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  • 351.
    Carlsen, Hanne Krage
    et al.
    Centre of Public Health Sciences, University of Iceland.
    Zoëga, Helga
    Valdimarsdóttir, Unnur
    Gíslason, Thórarinn
    Hrafnkelsson, Birgir
    Hydrogen sulfide and particle matter levels associated with increased dispensing of anti-asthma drugs in Iceland's capital2012In: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 113, p. 33-39Article in journal (Refereed)
    Abstract [en]

    Background Air pollutants in Iceland's capital area include hydrogen sulfide (H2S) emissions from geothermal power plants, particle pollution (PM10) and traffic-related pollutants. Respiratory health effects of exposure to PM and traffic pollutants are well documented, yet this is one of the first studies to investigate short-term health effects of ambient H2S exposure.

    Objectives The aim of this study was to investigate the associations between daily ambient levels of H2S, PM10, nitrogen dioxide (NO2) and ozone (O3), and the use of drugs for obstructive pulmonary diseases in adults in Iceland's capital area.

    Methods The study period was 8 March 2006 to 31 December 2009. We used log-linear Poisson generalized additive regression models with cubic splines to estimate relative risks of individually dispensed drugs by air pollution levels. A three-day moving average of the exposure variables gave the best fit to the data. Final models included significant covariates adjusting for climate and influenza epidemics, as well as time-dependent variables.

    Results The three-day moving average of H2S and PM10 levels were positively associated with the number of individuals who were dispensed drugs at lag 3–5, corresponding to a 2.0% (95% confidence interval [CI] 0.4, 3.6) and 0.9% (95% CI 0.1, 1.8) per 10 μg/m3 pollutant concentration increase, respectively.

    Conclusion Our findings indicated that intermittent increases in levels of particle matter from traffic and natural sources and ambient H2S levels were weakly associated with increased dispensing of drugs for obstructive pulmonary disease in Iceland's capital area. These weak associations could be confounded by unevaluated variables hence further studies are needed.

  • 352.
    Carlsson, Amelie
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences.
    Reproducerbarhet i öga-nacke/skuldra besvär hos yrkesverksamma mikroskoparbetare: Självskattade besvär inom och mellan måndagar och fredagar under två separata arbetsveckor2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: Microscopy at work involves a combination of external exposures that pose an increased risk for eye-neck/shoulder symptoms such as; visually demanding near work, eye-hand coordination, static work postures and repetitive work.

    Objectives: To explore the pattern of fluctuations in eye-neck/shoulder symptoms and the reproducibility of these fluctuations during separate workdays and workweeks, for individuals who regularly perform microscopic duties at work.

    Method: Data was collected at 8 different times for all participants (n=16); Monday morning and afternoon and Friday morning and afternoon, during 2 different weeks at work.

    Results: Musculoskeletal complaints in the neck/shoulders and symptoms of eye strain increased significantly (∆Musculoskeletal complaints; p<0,01, ∆Symptoms of eye stain; p<0,05)  during the workweek.  The highest levels of self-reported symptoms did not correlate with the self-reported time in microscopy during the workweek (p>0.05).  The same tendency for the increments in symptoms was observed during both work weeks. Only for musculoskeletal complaints did the increments of symptoms correlated with one another (p<0.05). 

    Conclusion: The results indicate that microscopy at work is a risk factor, primarily for increased musculoskeletal complaints in the neck/shoulders. More studies are needed to assess the relationship between microscopy at work and the onset and development of eye-neck/shoulder complaints.

  • 353.
    Carlsson, Daniel
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Effects of cold and hand-arm vibration on the peripheral neurosensory and vascular system: an occupational perspective2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background In Swedish working life, exposure to cold and exposure to hand-arm vibration (HAV) are two common health hazards. Health effects of HAV in the neurosensory, vascular and musculoskeletal systems are collectively denoted hand-arm vibration syndrome (HAVS), and have been thoroughly studied. Effects of cold exposure in terms of effects on the peripheral neurosensory and vascular system are on the contrary limited, especially in an occupational setting. Effects of cold exposure or cold injury have not previously been assessed with quantitative sensory testing (QST). Commonly reported symptoms after exposure to HAV and after cold injuries, includes cold sensitivity and sensation of cold. Cold sensitivity can also occur without previous exposure to vibration or cold and may have a major impact on quality of life. Other possible risk factors for cold sensitivity need to be assessed. Sensation of cold hands could theoretically imply an early manifestation of damage to the neurosensory or vascular system, and therefore be of importance to enable early detection of vascular and neurosensory HAVS. The purpose of this thesis was to increase the knowledge about health effects from cold and HAV on the peripheral neurosensory and vascular system, with an occupational perspective. The aims were: first, to identify and evaluate health effects and sequelae in the peripheral neurosensory and vascular system due to cold injury and cold exposure; second, to investigate if sensation of cold hands is a predictor for future onset of Raynaud's phenomenon or paresthesia; and third, to identify possible risk factors associated with cold sensitivity.

    Methods A case series on 15 military conscripts with local cold injuries in the hands or feet, involving QST and symptom descriptions, was conducted to investigate the hypothesis that cold injuries can result in similar neurosensory and vascular impairments as in HAVS. To assess health effects of cold exposure, a cohort study on 54 military conscripts in cold winter military training, with cold exposure assessments, was conducted. Possible health effects were assessed after 14 months of military training, containing considerable cold exposure, by means of QST, Finger systolic blood pressure after local cooling (FSBP) and a questionnaire. To investigate if sensation of cold hands is a predictor for vascular or neurosensory HAVS we investigated a cohort of 178 employees at a manufacturing company where HAV was a common exposure. The cohort was followed during 21 years and both vibration exposure and health outcomes were assessed regularly. Questionnaire items were used to assess sensations of cold hands as well as signs of Raynaud’s phenomenon and paresthesia. To identify risk factors for cold sensitivity a case-control study was conducted involving 997iiiparticipants from the general population in northern Sweden. The study was cross-sectional and explored possible risk factors for cold sensitivity.

    Results Cold injuries and cold exposure were associated with reduced sensibility in QST and increase severity and prevalence of neurosensory and vascular symptoms. Our results did not show any impairment in peripheral blood flow due to cold exposure, detectable by FSBP. The risk of developing Raynaud's phenomenon was increased for workers previously reporting sensation of cold hands (OR 6.3, 95% CI 2.3-17.0). No increased risk for paresthesia in relation to a sensation of cold hands was observed. The identified risk factors for cold sensitivity were frostbite in the hands, rheumatic disease, nerve injury in upper extremities or neck, migraine and vascular disease. When analysing women and men separately, women’s risk factors were frostbite in the hands, rheumatic disease, migraine and cold exposure. Men’s risk factors were frostbite in the hands, vibration exposure and nerve injury in upper extremities or neck. BMI > 25 was a protective factor for both men and women.

    Conclusion Cold injury and cold exposure are associated with impairments in the neurosensory system, detectable by QST. Symptoms such as sensation of cold hands and white fingers indicate vascular involvement, even though no vascular impairments due to cold exposure could be detected by objective measurements. A sensation of cold hands is a risk factor for development of Raynaud´s phenomenon, but not for paresthesia. At the individual level, reporting cold hands does not appear to be useful information when considering the possibility of a future development of Raynaud’s phenomenon. Frostbite in the hands is a risk factor for cold sensitivity among both women and men. For women rheumatic disease, migraine and cold exposure are also independent risk factors, and for men, exposure to HAV. Being overweight is a protective factor for both women and men.

  • 354.
    Carlsson, Daniel
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine. Sundsvall Hosp, Dept Occupat & Environm Med, SE-85186 Sundsvall, Sweden.
    Burström, Lage
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Heldestad Lilliesköld, Victoria
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Nilsson, Tohr
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine. Sundsvall Hosp, Dept Occupat & Environm Med, SE-85186 Sundsvall, Sweden.
    Nordh, Erik
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Wahlström, Jens
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Neurosensory sequelae assessed by thermal and vibrotactile perception thresholds after local cold injury2014In: International Journal of Circumpolar Health, ISSN 1239-9736, E-ISSN 2242-3982, Vol. 73, article id 23540Article in journal (Refereed)
    Abstract [en]

    Background. Local freezing cold injuries are common in the north and sequelae to cold injury can persist many years. Quantitative sensory testing (QST) can be used to assess neurosensory symptoms but has previously not been used on cold injury patients.

    Objective. To evaluate neurosensory sequelae after local freezing cold injury by thermal and vibrotactile perception thresholds and by symptom descriptions.

    Design. Fifteen patients with a local freezing cold injury in the hands or feet, acquired during military training, were studied with QST by assessment of vibrotactile (VPT), warmth (WPT) and cold (CPT) perception thresholds 4 months post-injury. In addition, a follow-up questionnaire, focusing on neurovascular symptoms, was completed 4 months and 4 years post-injury.

    Results. QST demonstrated abnormal findings in one or both affected hands for VPT in 6 patients, for WPT in 4 patients and for CPT in 1 patient. In the feet, QST was abnormal for VPT in one or both affected feet in 8 patients, for WPT in 6 patients and for CPT in 4 patients. Freezing cold injury related symptoms, e. g. pain/discomfort when exposed to cold, cold sensation and white fingers were common at 4 months and persisted 4 years after the initial injury.

    Conclusions. Neurosensory sequelae after local freezing cold injury, in terms of abnormal thermal and/or vibration perception thresholds, may last at least 4 months after the initial injury. Symptoms such as pain/discomfort at cold exposure, cold sensations and white fingers may persist at least 4 years after the initial injury.

  • 355.
    Carlsson, Daniel
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Pettersson, Hans
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Burström, Lage
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nilsson, Tohr
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Wahlström, Jens
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Neurosensory and vascular function after 14 months of military training comprising cold winter conditions2016In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 42, no 1, p. 61-70Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: This study aimed to examine the effects of 14 months of military training comprising cold winter conditions on neurosensory and vascular function in the hands and feet.

    METHODS: Military conscripts (N=54) were assessed with quantitative sensory testing comprising touch, temperature, and vibration perception thresholds and finger systolic blood pressure (FSBP) after local cooling and a questionnaire on neurosensory and vascular symptoms at both baseline and follow-up. Ambient air temperature was recorded with body worn temperature loggers.

    RESULTS: The subjects showed reduced sensitivity to perception of touch, warmth, cold and vibrations in both the hands and feet except from vibrotactile perception in digit two of the right hand (right dig 2). Cold sensations, white fingers, and pain/discomfort when exposed to cold as well as pain increased in both prevalence and severity. There were no statistically significant changes in FSBP after local cooling.

    CONCLUSION: Fourteen months of winter military training comprising cold winter conditions reduced sensation from touch, warmth, cold, and vibrotactile stimulus in both hands and feet and increased the severity and prevalence of symptoms and pain. The vascular function in the hands, measured by FSBP after local cooling, was not affected.

  • 356.
    Carlsson, Daniel
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Wahlström, Jens
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Burström, Lage
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Hagberg, Mats
    Avd för samhällsmedicin och folkhälsa vid Institutionen för medicin, Göteborgs universitet.
    Lundström, Ronnie
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Pettersson, Hans
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nilsson, Tohr
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Can sensation of cold hands predict Raynaud’s phenomenon or paresthesia?2018In: Occupational Medicine, ISSN 0962-7480, E-ISSN 1471-8405, Vol. 68, no 5, p. 314-319Article in journal (Refereed)
    Abstract [en]

    Background: Raynaud's phenomenon and neurosensory symptoms are common after hand-arm vibration exposure. Knowledge of early signs of vibration injuries is needed. Aims: To investigate the risk of developing Raynaud's phenomenon and paraesthesia in relation to sensation of cold hands in a cohort of male employees at an engineering plant. Methods: We followed a cohort of male manual and office workers at an engineering plant in Sweden for 21 years. At baseline (1987 and 1992) and each follow-up (1992, 1997, 2002, 2008), we assessed sensation of cold, Raynaud's phenomenon and paraesthesia in the hands using questionnaires and measured vibration exposure. We calculated risk estimates with univariate and multiple logistic regression analyses and adjusted for vibration exposure and tobacco usage. Results: There were 241 study participants. During the study period, 21 individuals developed Raynaud's phenomenon and 43 developed paraesthesia. When adjusting the risk of developing Raynaud's phenomenon for vibration exposure and tobacco use, the odds ratios were between 6.0 and 6.3 (95% CI 2.2-17.0). We observed no increased risk for paraesthesia in relation to a sensation of cold hands. Conclusions: A sensation of cold hands was a risk factor for Raynaud's phenomenon. At the individual level, reporting a sensation of cold hands did not appear to be useful information to predict future development of Raynaud's phenomenon given a weak to moderate predictive value. For paraesthesia, the sensation of cold was not a risk factor and there was no predictive value at the individual level.

  • 357.
    Carlsson, Maria
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Samband mellan rörelseutslag i ryggkotpelaren och antropometriska mått vid exponering för mekanisk stöt i sittande: En laboratorieundersökning2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sammanfattning: Vid körning av maskiner i terräng utsätts kroppen för mekaniska stötar och vibrationer vilket kan ge muskuloskeletala besvär, främst i ryggraden. Det saknas kunskap om hur kroppsliga reaktioner vid mekanisk stöt påverkas av kroppens storleksförhållanden (antropometri). Syfte: Att undersöka samband mellan rörelseutslag i ryggkotpelaren och antropometriska mått då en person utsätts för en translatorisk stöt i sidled under sittande position. Vidare var syftet att se om sambandet påverkades om personen samtidigt utför en kognitiv uppgift då forskning visat att det kan påverka postural kontroll i andra situationer. Metod: Tjugotre friska manliga forskningspersoner (19-36år) satt på en stol monterad på en rörelsesimulator. De utsattes för 10 stötar med eller utan samtidig kognitiv uppgift. Rörelseutslag registrerades som relativa vinklar mellan olika ryggsegment genom orienteringsmätare fästa på huden. Resultat: Flera svaga men signifikanta samband fanns. Det högst uppmätta korrelationsvärdet var r=0,55 (avstånd mellan huvud-sits och rörelseutslag i nacken). Inga starka samband gick att finna och att samtidigt utföra en kognitiv uppgift påverkade inte sambanden. Slutsats: Antropometriska mått tycks ha viss betydelse för hur stora rörelseutslagen blir i ryggraden hos unga friska män som utsätts för mekanisk stöt. Sambanden påverkas inte av att man samtidigt utför en kognitiv uppgift.

  • 358.
    Carlsson, Ruth
    et al.
    Swedish Work Environment Authority.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Physical variation at work – a scientific review2016In: NES2016 - Ergonomics in theory and practice: Proceedings of 48th Annual Conference of Nordic Ergonomics and Human Factors Society / [ed] Järvelin-Pasanen, S, 2016, p. 156-159Conference paper (Refereed)
    Abstract [en]

    Physical variation is generally considered to be an important factor influencing the risk for musculoskeletal disorders in repetitive work, but a comprehensive scientific basis for this assumption has not been available. Thus, the Swedish Work Environment Authority requested the Centre for Musculoskeletal Research at the University of Gävle to review scientific standings regarding physical variation and its effects.  In total, 56 articles were included in the review. The results showed that occupationally relevant studies of the effects of physical variation are few, and that the effectiveness of initiatives promoting variation has also been studied to a limited extent. Thus, current research cannot provide a clear answer to what an effective combination would be of work tasks in a job in the context of physical variation, let alone the optimal time distribution of tasks in a short (hours, days) and long (weeks, months, years) perspective. Also, gender aspects of physical variation were considered to a very limited extent. There is a need for more studies of relevant initiatives aiming at creating increased physical variation by changing the contents of work or its temporal structure; including studies placing this issue in a gender perspective.

  • 359.
    Carrwik, Christian
    et al.
    Department of Surgical Sciences, Uppsala University Hospital, Uppsala, Sweden.
    Murakami, Hideki
    Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
    Willander, Johan
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work and Psychology, Psychology.
    Robinson, Yohan
    Department of Surgical Sciences, Uppsala University Hospital, Uppsala, Sweden.
    Potential harms of interventions for spinal metastatic disease2017In: Cochrane Database of Systematic Reviews, ISSN 1469-493X, E-ISSN 1469-493X, Vol. -, no 7, article id CD012724Article in journal (Refereed)
    Abstract [en]

    This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: The primary objective of this review is to compare the potential harms of treatment for spinal metastatic disease for the following treatments: 1. Surgical intervention. 2. Surgical intervention with radiation therapy. 3. Radiation therapy alone. Our secondary objectives are: 1. comparing the harms of different surgical methods; 2. comparing the harms between different radiation protocols.

  • 360. Carsin, Anne-Elie
    et al.
    Fuertes, Elaine
    Schaffner, Emmanuel
    Jarvis, Debbie
    Antó, Josep M.
    Heinrich, Joachim
    Bellisario, Valeria
    Svanes, Cecilie
    Keidel, Dirk
    Imboden, Medea
    Weyler, Joost
    Nowak, Dennis
    Martinez-Moratalla, Jesus
    Gullón, José-Antonio
    Sanchez Ramos, José Luis
    Caviezel, Seraina
    Beckmeyer-Borowko, Anna
    Raherison, Chantal
    Pin, Isabelle
    Demoly, Pascal
    Cerveri, Isa
    Accordini, Simone
    Gislason, Thorarinn
    Toren, Kjell
    Department of Public Health and Community Medicine, Institute of Medicine, Goteburg, Sweden..
    Forsberg, Bertil
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Janson, Christer
    Department of Medical Sciences, Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden..
    Jogi, Rain
    Emtner, Margareta
    Gómez Real, Francisco
    Raza, Wasif
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Leynaert, Bénédicte
    Pascual, Silvia
    Guerra, Stefano
    Dharmage, Shyamali C.
    Probst-Hensch, Nicole
    Garcia-Aymerich, Judith
    Restrictive spirometry pattern is associated with low physical activity levels: A population based international study2019In: Respiratory Medicine, ISSN 0954-6111, E-ISSN 1532-3064, Vol. 146, p. 116-123Article in journal (Refereed)
    Abstract [en]

    Introduction: Restrictive spirometry pattern is an under-recognised disorder with a poor morbidity and mortality prognosis. We compared physical activity levels between adults with a restrictive spirometry pattern and with normal spirometry.

    Methods: Restrictive spirometry pattern was defined as a having post-bronchodilator FEV1/FVC ≥ Lower Limit of Normal and a FVC<80% predicted in two population-based studies (ECRHS-III and SAPALDIA3). Physical activity was measured using the International Physical Activity Questionnaire. The odds of having low physical activity (<1st study-specific tertile) was evaluated using adjusted logistic regression models.

    Results: Subjects with a restrictive spirometry pattern (n = 280/4721 in ECRHS, n = 143/3570 in SAPALDIA) reported lower levels of physical activity than those with normal spirometry (median of 1770 vs 2253 MET·min/week in ECRHS, and 3519 vs 3945 MET·min/week in SAPALDIA). Subjects with a restrictive spirometry pattern were more likely to report low physical activity (meta-analysis odds ratio: 1.41 [95%CI 1.07–1.86]) than those with a normal spirometry. Obesity, respiratory symptoms, co-morbidities and previous physical activity levels did not fully explain this finding.

    Conclusion: Adults with a restrictive spirometry pattern were more likely to report low levels of physical activity than those with normal spirometry. These results highlight the need to identify and act on this understudied but prevalent condition.

  • 361. Catalano, Ralph
    et al.
    Karasek, Deborah
    Gemmill, Alison
    Falconi, April
    Goodman, Julia
    Magganas, Aristotle
    Hartig, Terry
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Institute for Housing and Urban Research.
    Very low birthweight: Dysregulated gestation versus evolutionary adaptation2014In: Social Science and Medicine, ISSN 0277-9536, E-ISSN 1873-5347, Vol. 108, p. 237-242Article in journal (Refereed)
    Abstract [en]

    Much medical literature attributes persistently high rates of very low birthweight (VLBW) to "dysregulated" gestation. We offer the alternative view that natural selection conserved well-regulated, though nonconscious, decisional biology that protects the reproductive fitness of women by spontaneously aborting gestations that would otherwise yield frail infants, particularly small males. Modern obstetric practice, however, converts some fraction of these erstwhile spontaneous abortions into live births of very small infants. We further propose that the nonconscious decisional biology of gestation exhibits preferences also seen in consciously made decisions. We hypothesize that the incidence of VLBW among male infants should vary with the population's self-reported intentions to assume financial risk. We apply time-series modeling to monthly birth counts by sex and weight from the Swedish Medical Birth Registry between January 1993 and December 2010. We gauge risk aversion with monthly data from the Micro Index of the Swedish Consumer Tendency Survey (MISCT). Consistent with our argument that nonconscious decisional biology shares risk aversion with conscious decisions, we find that the incidence of VLBW among male infants in Sweden varies with the population's self-reported intentions to assume financial risk. We find increases above expected odds of a very low weight infant among males born 1 month after increases above expected levels of self-reported risk aversion in the Swedish population. We offer this finding as support for the argument that persistently high rates of VLBW arise, at least in part, from a combination of medical interventions and mechanisms conserved by natural selection to protect reproductive fitness. (C) 2014 Elsevier Ltd. All rights reserved.

  • 362. Cecchi, L
    et al.
    D'Amato, G
    Ayres, JG
    Galan, C
    Forastiere, F
    Forsberg, Bertil
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Gerritsen, J
    Nunes, C
    Behrendt, H
    Akdis, C
    Dahl, R
    Annesi-Maesano, I
    Projections of the effects of climate change on allergic asthma: the contribution of aerobiology2010In: Allergy. European Journal of Allergy and Clinical Immunology, ISSN 0105-4538, E-ISSN 1398-9995, Vol. 65, no 9, p. 1073-1081Article in journal (Refereed)
    Abstract [en]

    Climate change is unequivocal and represents a possible threat for patients affected by allergic conditions. It has already had an impact on living organisms, including plants and fungi with current scenarios projecting further effects by the end of the century. Over the last three decades, studies have shown changes in production, dispersion and allergen content of pollen and spores, which may be region- and species-specific. In addition, these changes may have been influenced by urban air pollutants interacting directly with pollen. Data suggest an increasing effect of aeroallergens on allergic patients over this period, which may also imply a greater likelihood of the development of an allergic respiratory disease in sensitized subjects and exacerbation of symptomatic patients. There are a number of limitations that make predictions uncertain, and further and specifically designed studies are needed to clarify current effects and future scenarios. We recommend: More stress on pollen/spore exposure in the diagnosis and treatment guidelines of respiratory and allergic diseases; collection of aerobiological data in a structured way at the European level; creation, promotion and support of multidisciplinary research teams in this area; lobbying the European Union and other funders to finance this research.

  • 363. Cedervall, Therese
    et al.
    Lind, P. Monica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Savendahl, Lars
    Expression of the Aryl Hydrocarbon Receptor in Growth Plate Cartilage and the Impact of Its Local Modulation on Longitudinal Bone Growth2015In: International Journal of Molecular Sciences, ISSN 1422-0067, E-ISSN 1422-0067, Vol. 16, no 4, p. 8059-8069Article in journal (Refereed)
    Abstract [en]

    Although dioxin has been reported to impair bone growth in both humans and animals, the underlying mechanisms have not been clarified. We conducted this study to rule out if dioxin may directly target the growth plate, via local modulation of the aryl hydrocarbon receptor (AhR). Initial studies in rare tissue samples of the human growth plate confirmed that the AhR protein is widely expressed in growth plate cartilage. To explore the local role of the AhR, mechanistic studies were performed in a well-established model of cultured fetal rat metatarsal bones. The longitudinal growth of these bones was monitored while being exposed to AhR modulators. The AhR agonist, 2,3,7,8-tetrachlorodibenzo-p-dioxin, did not affect bone growth at any concentrations tested (1 pM-10 nM). In contrast, the AhR antagonist, alpha-naphthoflavone, suppressed bone growth and increased chondrocyte apoptosis, although only at a high, potentially cytotoxic concentration (50 mu M). We conclude that although the AhR is widely expressed in the growth plate, bone growth is not modulated when locally activated, and therefore, dioxin-induced growth failure is likely mediated through systemic rather than local actions.

  • 364. Celeste, Roger Keller
    et al.
    Nadanovsky, Paulo
    Fritzell, Johan
    Stockholm University, Faculty of Social Sciences, Centre for Health Equity Studies (CHESS).
    Trends in socioeconomic disparities in the utilization of dental care in Brazil and Sweden2011In: Scandinavian Journal of Public Health, ISSN 1403-4948, E-ISSN 1651-1905, Vol. 39, no 6, p. 640-648Article in journal (Refereed)
    Abstract [en]

    Aims: To describe trends in socioeconomic disparities in utilization of dental care. Methods: We obtained cross-sectional data from Sweden in the period 1968-2000 and from Brazil in 1986 and 2002 for 16 state capitals. The outcome was the percentage of people who reported that they had visited the dentist in the last 12 months, calculated for a higher and a lower income group and stratified by sex, age (two groups: young and adults) and dental status. Adjusted prevalence differences and prevalence ratios were produced using Poisson regression. Results: In Brazil, there was a decline in use of dental care among the 15-19 year olds in the period 1986-2002, but not among the 35-44 year olds. In Sweden, there was a decline among the young and adults between 1991 and 2000. Overall, socioeconomic disparities in use of dental services between the higher and the lower economic groups showed a decline in both countries. The reduction in disparities among young Brazilians was 1.1 percentage points per year (p < 0.01), but among the other age groups the decline was not significant (p>0.01). In the last surveys, the gap remained in both countries and age groups (p < 0.01). Conclusions: The recent decline in utilization of dental care and in the socioeconomic gap may mirror improvements in oral health. However, there are still relevant and persistent disparities in utilization of dental care in both countries, with a higher proportion of people of higher socioeconomic status visiting the dentist.

  • 365.
    Cha, Yingying
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Tu, Minghui
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Elmgren, Max
    SLB-analys, Environment and Health Administration, Stockholm, Sweden.
    Silvergren, Sanna
    SLB-analys, Environment and Health Administration, Stockholm, Sweden.
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Factors affecting the exposure of passengers, service staff and train drivers inside trains to airborne particles2018In: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 166, p. 16-24Article in journal (Refereed)
    Abstract [en]

    This study investigated train air conditioning filters, interior ventilation systems, tunnel environments and platform air quality as factors affecting the concentrations of airborne particles inside trains and provides information on the exposure of passengers, train drivers and service staff to particles. Particle sampling was done inside the passenger cabin, the driver cabin and the service staff cabin during on-board measurement campaigns in 2016 and 2017. The results show that interior ventilation plays a key role in maintaining cleaner in-train air. Noticeable increases in PM10 and PM2.5 levels were observed for all of the measured cabins when the train was running in the newly opened tunnel. The increases occurred when the doors of the passenger cabin and the service staff cabin were open at underground stations. The door to the driver cabin, which remained closed for the entire measurement period, acted as a filter for coarse particles (PM2.5–10). The highest particle exposure occurred in the passenger cabin, followed by the service staff cabin, while the driver had the lowest exposure. The highest deposition dose occurs for the service staff and the lowest for commuters.

  • 366. Chen, Chih-Mei
    et al.
    Thiering, Elisabeth
    Zock, Jan-Paul
    Villani, Simona
    Olivieri, Mario
    Modig, Lars
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Jarvis, Deborah
    Norbaeck, Dan
    Verlato, Giuseppe
    Heinrich, Joachim
    Is There a Threshold Concentration of Cat Allergen Exposure on Respiratory Symptoms in Adults?2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 6, article id e0127457Article in journal (Refereed)
    Abstract [en]

    Background and Objective Cat allergen concentrations higher than 8 mu g/g in settled house dust, have been suggested to provoke exacerbation of allergic respiratory symptoms. However, whether the 8 mu g/g of indoor cat allergen concentration is indeed the minimal exposure required for triggering the asthma related respiratory symptoms or the development of sensitization has not yet been confirmed. We studied the associations between domestic cat allergen concentrations and allergic symptoms in the European Community Respiratory Health Survey II, with the aim of confirming this suggested threshold. Methods Cat allergen concentrations were measured in the mattress dust of 3003 participants from 22 study centres. Levels of specific immunoglobulin E to cat allergens were measured in serum samples using an immunoassay. Information on allergic symptoms, medication use, home environment and smoking was obtained from a face-to-face interview. Results Domestic cat allergen concentrations were not associated with allergic/asthmatic symptoms in the entire study population, nor in the subset sensitized to cat allergen. We also found no association among individuals exposed to concentrations higher than 8 mu g/g. However, exposure to medium cat allergen concentrations (0.24-0.63 mu g/g) was positively associated with reported asthmatic respiratory symptoms in subjects who have experienced allergic symptoms when near animals. Conclusions The proposed 8 mu g/g threshold of cat allergen concentrations for the exacerbation of allergic/respiratory symptoms was not confirmed in a general European adult population. Potential biases attributable to avoidance behaviours and an imprecise exposure assessment cannot be excluded.

  • 367. Chen, Chih-Mei
    et al.
    Thiering, Elisabeth
    Zock, Jan-Paul
    Villani, Simona
    Olivieri, Mario
    Modig, Lars
    Jarvis, Deborah
    Norbäck, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Verlato, Giuseppe
    Heinrich, Joachim
    Is There a Threshold Concentration of Cat Allergen Exposure on Respiratory Symptoms in Adults?2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 6, article id e0127457Article in journal (Refereed)
    Abstract [en]

    Background and Objective Cat allergen concentrations higher than 8 mu g/g in settled house dust, have been suggested to provoke exacerbation of allergic respiratory symptoms. However, whether the 8 mu g/g of indoor cat allergen concentration is indeed the minimal exposure required for triggering the asthma related respiratory symptoms or the development of sensitization has not yet been confirmed. We studied the associations between domestic cat allergen concentrations and allergic symptoms in the European Community Respiratory Health Survey II, with the aim of confirming this suggested threshold. Methods Cat allergen concentrations were measured in the mattress dust of 3003 participants from 22 study centres. Levels of specific immunoglobulin E to cat allergens were measured in serum samples using an immunoassay. Information on allergic symptoms, medication use, home environment and smoking was obtained from a face-to-face interview. Results Domestic cat allergen concentrations were not associated with allergic/asthmatic symptoms in the entire study population, nor in the subset sensitized to cat allergen. We also found no association among individuals exposed to concentrations higher than 8 mu g/g. However, exposure to medium cat allergen concentrations (0.24-0.63 mu g/g) was positively associated with reported asthmatic respiratory symptoms in subjects who have experienced allergic symptoms when near animals. Conclusions The proposed 8 mu g/g threshold of cat allergen concentrations for the exacerbation of allergic/respiratory symptoms was not confirmed in a general European adult population. Potential biases attributable to avoidance behaviours and an imprecise exposure assessment cannot be excluded.

  • 368.
    Chen, Fei'er
    et al.
    Fudan Univ, Sch Publ Hlth, Dept Environm Hlth, Shanghai 200032, Peoples R China..
    Lin, Zhijing
    Fudan Univ, Sch Publ Hlth, Dept Environm Hlth, Shanghai 200032, Peoples R China..
    Chen, Renjie
    Fudan Univ, Sch Publ Hlth, Dept Environm Hlth, Shanghai 200032, Peoples R China.;Natl Hlth & Family Planning Commiss Peoples Repub, Shanghai Key Lab Meteorol & Hlth, Key Lab Hlth Technol Assessment, Key Lab Publ Hlth Safety,Minist Educ, Shanghai 200032, Peoples R China..
    Norbäck, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine. Uppsala Univ, Dept Med Sci Occupat & Environm Med, SE-751 Uppsala, Sweden..
    Liu, Cong
    Fudan Univ, Sch Publ Hlth, Dept Environm Hlth, Shanghai 200032, Peoples R China..
    Kan, Haidong
    Fudan Univ, Sch Publ Hlth, Dept Environm Hlth, Shanghai 200032, Peoples R China.;Natl Hlth & Family Planning Commiss Peoples Repub, Shanghai Key Lab Meteorol & Hlth, Key Lab Hlth Technol Assessment, Key Lab Publ Hlth Safety,Minist Educ, Shanghai 200032, Peoples R China..
    Deng, Qihong
    Cent S Univ, Sch Energy Sci & Engn, Changsha 410083, Hunan, Peoples R China..
    Huang, Chen
    Univ Shanghai Sci & Technol, Sch Environm & Architecture, Shanghai 200093, Peoples R China..
    Hu, Yu
    Univ Shanghai Sci & Technol, Sch Environm & Architecture, Shanghai 200093, Peoples R China..
    Zou, Zhijun
    Univ Shanghai Sci & Technol, Sch Environm & Architecture, Shanghai 200093, Peoples R China..
    Liu, Wei
    Univ Shanghai Sci & Technol, Sch Environm & Architecture, Shanghai 200093, Peoples R China..
    Wang, Juan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Lu, Chan
    Cent S Univ, Sch Energy Sci & Engn, Changsha 410083, Hunan, Peoples R China..
    Qian, Hua
    Southeast Univ, Sch Energy & Environm, Nanjing 210096, Jiangsu, Peoples R China..
    Yang, Xu
    Cent China Normal Univ, Coll Life Sci, Wuhan 430079, Hubei, Peoples R China..
    Zhang, Xin
    Shanxi Univ, Res Ctr Environm Sci & Engn, Taiyuan 030006, Shanxi, Peoples R China..
    Qu, Fang
    Tsinghua Univ, Dept Bldg Sci, Beijing 100084, Peoples R China..
    Sundell, Jan
    Tsinghua Univ, Dept Bldg Sci, Beijing 100084, Peoples R China..
    Zhang, Yinping
    Tsinghua Univ, Dept Bldg Sci, Beijing 100084, Peoples R China..
    Li, Baizhan
    Chongqing Univ, Key Lab Three Gorges Reservoir Reg Ecoenvironm, Chongqing 400030, Peoples R China..
    Sun, Yuexia
    Tianjin Univ, Sch Environm Sci & Engn, Tianjin 300350, Peoples R China..
    Zhao, Zhuohui
    Fudan Univ, Sch Publ Hlth, Dept Environm Hlth, Shanghai 200032, Peoples R China.;Natl Hlth & Family Planning Commiss Peoples Repub, Shanghai Key Lab Meteorol & Hlth, Key Lab Hlth Technol Assessment, Key Lab Publ Hlth Safety,Minist Educ, Shanghai 200032, Peoples R China..
    The effects of PM2.5 on asthmatic and allergic diseases or symptoms in preschool children of six Chinese cities, based on China, Children, Homes and Health (CCHH) project2018In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 232, p. 329-337Article in journal (Refereed)
    Abstract [en]

    The urbanization and industrialization in China is accompanied by bad air quality, and the prevalence of asthma in Chinese children has been increasing in recent years. To investigate the associations between ambient PM2.5 levels and asthmatic and allergic diseases or symptoms in preschool children in China, we assigned PM2.5 exposure data from the Global Burden of Disease (GBD) project to 205 kindergartens at a spatial resolution of 0.1° × 0.1° in six cities in China (Shanghai, Nanjing, Chongqing, Changsha, Urumqi, and Taiyuan). A hierarchical multiple logistical regression model was applied to analyze the associations between kindergarten-level PM2.5 exposure and individual-level outcomes of asthmatic and allergic symptoms. The individual-level variables, including gender, age, family history of asthma and allergic diseases, breastfeeding, parental smoking, indoor dampness, interior decoration pollution, household annual income, and city-level variable-annual temperature were adjusted. A total of 30,759 children (average age 4.6 years, 51.7% boys) were enrolled in this study. Apart from family history, indoor dampness, and decoration as predominant risk factors, we found that an increase of 10 μg/m3 of the annual PM2.5 was positively associated with the prevalence of allergic rhinitis by an odds ratio (OR) of 1.20 (95% confidence interval [CI] 1.11, 1.29) and diagnosed asthma by OR of 1.10 (95% CI 1.03, 1.18). Those who lived in non-urban (vs. urban) areas were exposed to more severe indoor air pollution arising from biomass combustion and had significantly higher ORs between PM2.5 and allergic rhinitis and current rhinitis. Our study suggested that long-term exposure to PM2.5 might increase the risks of asthmatic and allergic diseases or symptoms in preschool children in China. Compared to those living in urban areas, children living in suburban or rural areas had a higher risk of PM2.5 exposure.

  • 369. Chen, Liang
    et al.
    Jin, Taiyi
    Huang, Bo
    Chang, Xiuli
    Lei, Lijian
    Nordberg, Gunnar F
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nordberg, Monica
    Plasma metallothionein antibody and cadmium-induced renal dysfunction in an occupational population in China.2006In: Toxicol Sci, ISSN 1096-6080, Vol. 91, no 1, p. 104-12Article in journal (Refereed)
  • 370. Chen, Liang
    et al.
    Lei, Lijian
    Jin, Taiyi
    Nordberg, Monica
    Nordberg, Gunnar F
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Plasma metallothionein antibody, urinary cadmium, and renal dysfunction in a Chinese type 2 diabetic population.2006In: Diabetes Care, ISSN 0149-5992, Vol. 29, no 12, p. 2682-7Article in journal (Refereed)
  • 371. Chen, Xiao
    et al.
    Wang, Zhongqiu
    Zhu, Guoying
    Nordberg, Gunnar F
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Ding, Xiaoqiang
    Jin, Taiyi
    The association between renal tubular dysfunction and zinc level in a Chinese population environmentally exposed to cadmium2018In: Biological Trace Element Research, ISSN 0163-4984, E-ISSN 1559-0720, Vol. 186, no 1, p. 114-121Article in journal (Refereed)
    Abstract [en]

    Microglobulin (UBMG) were measured. The median UCd, BCd, SZn, and HZn were 2.8 and 13.6 μg/g cr, 1.3 and 12.2 μg/L, 1.31 and 1.12 mg/L, and 0.14 and 0.12 mg/g in subjects living in control and polluted areas. The UBMG level of subjects living in the polluted area was significantly higher than that of the control (0.27 vs 0.11 mg/g cr, p < 0.01). SZn, HZn, and Zn/Cd ratios were negatively correlated with UBMG (p < 0.05 or 0.01). Subjects with high SZn concentrations (≥ 1.62 mg/L) had reduced risks of elevated UBMG [(odds ratio (OR) = 0.26, 95% confidence interval (CI) 0.07-0.99)] after controlling for multiple covariates compared with those with lower zinc levels. A similar result was observed in subjects with high HZn (OR = 0.09, 95% CI 0.02-0.48). The ORs of the second, third, and fourth quartiles of Zn/Cd ratio were 0.40 (95% CI 0.19-0.84), 0.14 (95% CI 0.06-0.37), and 0.01 (95% CI 0.02-0.18) for renal dysfunction compared with those of the first quartile, respectively. For those subjects with high level of UCd, high level of SZn and HZn also had reduced risks of elevated UBMG. The results of the present study show that high zinc body burden is associated with a decrease risk of renal tubular dysfunction induced by cadmium. Zinc nutritional status should be considered in evaluating cadmium-induced renal damage.

  • 372. Chen, Xiao
    et al.
    Wang, Zhongqiu
    Zhu, Guoying
    Nordberg, Gunnar F.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Jin, Taiyi
    Ding, Xiaoqiang
    The association between cumulative cadmium intake and osteoporosis and risk of fracture in a Chinese population2019In: Journal of Exposure Science and Environmental Epidemiology, ISSN 1559-0631, E-ISSN 1559-064X, Vol. 29, no 3, p. 435-443Article in journal (Refereed)
    Abstract [en]

    Bone is one of the target organs for cadmium toxicity. However, few studies have shown the association between cumulative cadmium intake and prevalence of osteoporosis and bone fracture. In the present study, we evaluated the association between cumulative cadmium intake and osteoporosis and risk of fracture in a Chinese population. A total of 790 subjects (488 women and 302 men) living in a control area and two cadmium-polluted areas were included. The cumulative cadmium intake was estimated by a food survey. The bone mineral density was determined by using single-photon absorptiometry. The cumulative cadmium intakes were 0.48, 2.14, and 11.00 g for men, and 0.42, 2.11, and 11.12 g in women in control, and moderately and heavily polluted areas, respectively. In women, the odds ratios (ORs) of subjects with a cadmium intake between 2.21 and 10.63 g and >10.63 g were 1.30 (95% CI: 0.58-2.94) and 2.36 (95% CI: 1.14-5.16), compared with those with a cadmium intake < 0.58 g after adjusting to the confounders for osteoporosis. The ORs of subjects with a cadmium intake >10.63 g were 2.34 (95% CI: 1.23-4.38) for all of the women and 2.62 (95% CI: 1.02-5.58) in women ≥ 60 years old, compared with those with a cadmium intake <10.63 g after adjusting to the confounders for bone fractures. In men, similar trends were observed, but no statistical significance was found. In addition, those subjects with renal tubular dysfunction showed high risk of bone fracture. Our results indicate that a high level of cumulative cadmium intake is associated with an increased rate of osteoporosis and fractures among women.

  • 373. Chen, Yiqin
    et al.
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Kaserzon, Sarit
    Wang, Xianyu
    Weijs, Liesbeth
    Gallen, Michael
    Toms, Leisa-Maree L.
    Li, Yan
    Aylward, Lesa L.
    Sly, Peter D.
    Mueller, Jochen E.
    Monthly variation in faeces: blood concentration ratio of persistent organic pollutants over the first year of life2016In: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 147, p. 259-268Article in journal (Refereed)
    Abstract [en]

    Previous studies have found that the concentrations of a range of persistent organic pollutants (POPs) in faeces is linearly proportional to the POP concentrations in blood of human adults irrespective of age and gender. In order to investigate the correlation between POP concentrations in faeces and blood in infants, the monthly variation of POP concentrations in faeces over the first year of life of one infant was investigated in this study and compared to modelled blood concentrations. Faecal samples were collected from one male infant daily. The samples were pooled by month and analysed for three selected POPs (2,2',4,4',5,5'-Hexachlorobiphenyl (PCB153), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and 2,2',4,4'-tetrabromodiphenyl ether (BDE47)). The POP concentrations in faecal samples increased for the first four months by a factor of 2.9, 4.9 and 1.4 for PCB153, BDE47, and p,p'-DDE, respectively. The faecal concentrations of all POPs decreased rapidly following the introduction of formula and solid food to the diet and subsequent weaning of the infant. Further, a one-compartment model was developed to estimate the daily POP concentrations in the blood of the infant. The POP concentrations in blood were predicted to vary much less over the first year than those observed in faeces. The faeces:blood concentration ratio of selected POPs (K-fb) differed significantly (P < 0.0001) between the period before and after weaning, and observed changes in K-fb are far greater than the uncertainty in the estimated K-fb. A more stable K-fb after weaning indicates the possibility of applying the stable K-fb values for non-invasive assessment of internal exposure in infants after weaning. The intra-individual variation in K-fb in infants is worthy of further investigation.

  • 374. Cherniack, Martin
    et al.
    Brammer, Anthony J
    Institute for Microstructural Sciences, National Research Council, Ottawa, Canada.
    Lundström, Ronnie
    Department of Biomedical Engineering and Informatics, University Hospital, Umeå, Sweden.
    Morse, Tim F.
    Neely, Greg
    Technical Risk Factors, National Institute for Working Life, Umeå, Sweden.
    Nilsson, Tohr
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Peterson, Donald
    Toppila, Esko
    Warren, Nicholas
    Diva, Ulysses
    Croteau, Marc
    Dussetschleger, Jefferey
    Syndromes from segmental vibration and nerve entrapment: observations on case definitions for carpal tunnel syndrome2008In: International Archives of Occupational and Environmental Health, ISSN 0340-0131, E-ISSN 1432-1246, Vol. 81, no 5, p. 661-669Article in journal (Refereed)
    Abstract [en]

    Objectives: The purpose of this paper is to assess the overlap and stability of two different case definitions of carpal tunnel syndrome CTS. The analysis considers the association between different case definitions and objective tests (sensory nerve conduction velocities, SNCVs and vibrotactile perception thresholds, TTS), and the natural history of CTS, in the context of two vibration-exposed cohorts.

    Methods: Clinical CTS cases were defined in two ways: (1) by the study physician using fixed criteria, and; (2) by questionnaire and hand diagram. SNCV in median and ulnar nerves was measured for digital, transpalmar, and transcarpal segments, and conventionally as from wrist-digit. Skin temperature was assessed as a point measurement by thermistor and regionally by thermal imaging. VTTs were determined at the bilateral fingertips of the third and fifth digits using a tactometer meeting the requirements of ISO 13091-1 (ISO 2001). The subjects were cohorts of shipyard workers in 2001 and 2004, and dental hygienists in 2002 and 2004.

    Results: Results are reported for 214 shipyard workers in 2001 and 135 in 2004, and for 94 dental hygienists in 2002 and 66 in 2004. In 2001, 50% of shipyard workers were diagnosed as CTS cases by at least one of the diagnostic schemes, but only 20% were positive by both criteria. Among study physician diagnosed cases, 64% were CTS negative in 2001, 76% were negative in 2004, 13% were positive in both years, 22% became negative after being positive, and 11% became positive after being negative. For only study physician diagnosed CTS did VTTs differ between cases differ and non-cases in digit 3; there was no such distinction in digit 5. The dental hygienists had little CTS.

    Conclusion: Clinical case definitions of CTS based on diagrams and self-assessment, and clinical evaluation have limited overlap. Combining clinical criteria to create a more narrow or specific case definition of CTS does not appear to predict SNCV. The natural history of CTS suggests a protean disorder with considerable flux in case status over time.

  • 375. Cherniack, Martin
    et al.
    Brammer, Anthony
    Lundström, Ronnie
    Morse, Timothy
    Neely, Gregory
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Nilsson, Tohr
    Peterson, Donald
    Toppila, Esko
    Warren, Nicholas
    Age and neuropathies in vibration exposed manual workers2009In: Canadian Acoustics, ISSN 0711-6659, E-ISSN 2291-1391, Vol. 37, no 3, p. 178-179Article in journal (Refereed)
  • 376. Cherniack, MG
    et al.
    Dussetschleger, J
    Björ, Bodil
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Musculoskeletal disease and disability in dentists2010In: Work: A journal of Prevention, Assesment and rehabilitation, ISSN 1051-9815, E-ISSN 1875-9270, Vol. 35, no 4, p. 411-418Article in journal (Refereed)
    Abstract [en]

    There is conflicting evidence on the extent that medical conditions, particularly musculoskeletal conditions related to work, cause disability and premature retirement in dentists. Reports based on data from disability insurance in the United States suggest dentists are not susceptible to work related musculoskeletal disability. Surveys of symptom rated debility suggest higher rates of dysfunction, however, as do compulsory employment injury reports from European countries. These data, including information on Swedish dentists, analyzed for this study, tend to put dentists at the higher end of health care professionals in terms of musculoskeletal injury and lost work time. Because compensation patterns and proprietorship vary between national systems, the relationship between exposure and injury and retirement from the active work force may include differing national characteristics.

  • 377. Cheung, Janet M. Y.
    et al.
    Atternäs, Kristina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Melchior, Madeleine
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Marshall, Nathaniel S.
    Fois, Romano A.
    Saini, Bandana
    Primary health care practitioner perspectives on the management of insomnia: a pilot study2014In: Australian Journal of Primary Health, ISSN 1448-7527, E-ISSN 1836-7399, Vol. 20, no 1, p. 103-112Article in journal (Refereed)
    Abstract [en]

    This paper reports a qualitative pilot study exploring primary care health practitioners' perspectives on the management of insomnia following the extensive media coverage on the adverse effects of zolpidem in 2007-08. General practitioners and community pharmacists were recruited throughout metropolitan Sydney, New South Wales using a convenience sampling and snowballing technique. Demographic information was collected from each participant followed by a semistructured interview. In total 22 participants were interviewed, including eight general practitioners and 14 community pharmacists. Interview transcripts were analysed using 'framework analysis'. Participants' responses illuminated some of the key issues facing primary care practitioners in the management of insomnia. Practitioners perceived there to be an overreliance on pharmacotherapy among insomnia patients and inadequate support for directing patients to alternative treatment pathways if they require or prefer non-pharmacological management. Current prescribing trends appear to favour older benzodiazepines in new cases of insomnia whereas some successful sporadic users of zolpidem have continued to use zolpidem after the media coverage in 2007-08. The findings of this pilot study suggest the need to address the limitations in the management of insomnia within the current health care system, to revise and disseminate updated insomnia guidelines and to provide educational opportunities and resources to primary care practitioners concerning management options.

  • 378. Christensen, Stine Holmegaard
    et al.
    Timm, Signe
    Janson, Christer
    Benediktsdóttir, Bryndis
    Forsberg, Bertil
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Holm, Mathias
    Jogi, Rain
    Johannessen, Ane
    Omenaas, Ernst
    Sigsgaard, Torben
    Svanes, Cecilie
    Schlünssen, Vivi
    A clear urban-rural gradient of allergic rhinitis in a population-based study in Northern Europe2016In: European clinical respiratory journal, ISSN 2001-8525, Vol. 3, article id 33463Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The protective effect of farm upbringing on allergic rhinitis is well known, but how upbringing in other environments influences the development of allergic rhinitis is scarcely investigated. The aim of this study was to investigate the association between place of upbringing and pet keeping in childhood and allergic rhinitis and nasal symptoms in adulthood.

    METHODS: The population-based Respiratory Health in Northern Europe study includes subjects from Denmark, Norway, Sweden, Iceland, and Estonia born in 1945-1973. This paper analyses 13,376 participants of the third study wave. Six categories of place of upbringing were defined: farm with livestock, farm without livestock, village in rural area, small town, city suburb, and inner city. Pets in the home at birth and during childhood were recorded. Data were analysed using adjusted logistic regression models.

    RESULTS: Livestock farm upbringing predicted less adult allergic rhinitis [odds ratio (OR) 0.68, 0.54-0.85] and nasal symptoms (OR 0.82, 0.68-0.99) than city upbringing, and an urban-rural gradient with decreasing risk per level of urbanisation was observed (OR 0.92, 0.88-0.94). Pets in the home at birth (OR 0.78, 0.68-0.88) and during childhood (OR 0.83, 0.74-0.93) were associated with less subsequent allergic rhinitis. Pet keeping did not explain the protective effect of place of upbringing.

    CONCLUSION: Risk of allergic rhinitis and nasal symptoms in adulthood was inversely associated with the level of urbanisation during upbringing. Pets at birth decreased the risk further, but did not explain the urban-rural gradient. Persistent beneficial effects of microbial diversity in early life might be an explanation for the findings.

  • 379. Chuang, Shu-Chun
    et al.
    Fanidi, Anouar
    Ueland, Per Magne
    Relton, Caroline
    Midttun, Oivind
    Vollset, Stein Emil
    Gunter, Marc J.
    Seckl, Michael J.
    Travis, Ruth C.
    Wareham, Nicholas
    Trichopoulou, Antonia
    Lagiou, Pagona
    Trichopoulos, Dimitrios
    Peeters, Petra H. M.
    Bueno-de-Mesquita, H. Bas
    Boeing, Heiner
    Wientzek, Angelika
    Kuehn, Tilman
    Kaaks, Rudolf
    Tumino, Rosario
    Agnoli, Claudia
    Palli, Domenico
    Naccarati, Alessio
    Ardanaz Aicua, Eva
    Sanchez, Maria-Jose
    Ramon Quiros, Jose
    Chirlaque, Maria-Dolores
    Agudo, Antonio
    Johansson, Mikael
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Grankvist, Kjell
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Boutron-Ruault, Marie-Christine
    Clavel-Chapelon, Francoise
    Fagherazzi, Guy
    Weiderpass, Elisabete
    Riboli, Elio
    Brennan, Paul J.
    Vineis, Paolo
    Johansson, Mattias
    Circulating Biomarkers of Tryptophan and the Kynurenine Pathway and Lung Cancer Risk2014In: Cancer Epidemiology, Biomarkers and Prevention, ISSN 1055-9965, E-ISSN 1538-7755, Vol. 23, no 3, p. 461-468Article in journal (Refereed)
    Abstract [en]

    Background: Imbalances in tryptophan metabolism have been linked to cancer-related immune escape and implicated in several cancers, including lung cancer. Methods: We conducted a nested case-control study within the European Prospective Investigation into Cancer andNutrition (EPIC) that included 893 incident lung cancer cases and 1,748matched controls. Circulating levels of tryptophan and six of its metabolites were measured and evaluated in relation to lung cancer risk. Results: Tryptophan (P-trend = 2 Chi 10(-5)) and the kynurenine/ tryptophan ratio (KTR; P-trend 4 Chi 10(-5)) were associated with lung cancer risk overall after adjusting for established risk factors. The ORs comparing the fifth and first quintiles (OR5th (vs. 1st)) were 0.52 [ 95% confidence interval (CI), 0.37-0.74] for tryptophan and 1.74 (95% CI, 1.24-2.45) for KTR. After adjusting for plasma methionine (available fromprevious work, which was strongly correlated with tryptophan), the associations of tryptophan (adjusted P-trend 0.13) and KTR (P-trend = 0.009) were substantially attenuated. KTR was positively associated with squamous cell carcinoma, the OR5th vs. 1st being 2.83 (95% CI, 1.62-4.94, P-trend -3 Chi 10(-5)) that was only marginally affected by adjusting for methionine. Conclusions: This study indicates that biomarkers of tryptophan metabolism are associated with subsequent lung cancer risk. Although this result would seem consistent with the immune system having a role in lung cancer development, the overall associations were dependent on methionine, and further studies are warranted to further elucidate the importance of these metabolites in lung cancer etiology. Impact: This is the first prospective study investigating the tryptophan pathway in relation to lung cancer risk.

  • 380.
    Ciccarelli, Marina
    et al.
    School of Occupational Therapy & Social Work, Curtin University, Perth, Australia.
    Straker, Leon
    School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Pollock, Clare
    Faculty of Health Sciences, Curtin University, Perth, Australia.
    Posture variation among office workers when using different information and communication technologies at work and away from work2014In: Ergonomics, ISSN 0014-0139, E-ISSN 1366-5847, Vol. 57, no 11, p. 1678-1686Article in journal (Refereed)
    Abstract [en]

    Office workers perform tasks using different information and communication technologies (ICT) involving various postures. Adequate variation in postures and muscle activity is generally believed to protect against musculoskeletal complaints, but insufficient information exists regarding the effect on postural variation of using different ICT. Thus, this study among office workers aimed to determine and compare postures and postural variation associated with using distinct types of ICT. Upper arm, head and trunk postures of 24 office workers were measured with the Physiometer® over a whole day in their natural work and away-from-work environments. Postural variation was quantified using two indices; APDF(90-10) and EVA(sd).Various ICT had different postural means and variation. Paper-based tasks had more non-neutral, yet also more variable postures. Electronics-based tasks had more neutral postures, with less postural variability. Tasks simultaneously using paper- and electronics-based ICT had least neutral and least variable postures. Tasks without ICT usually had the most posture variability. Interspersing tasks involving different ICT could increase overall exposure variation among office workers and may thus contribute to musculoskeletal risk reduction.

  • 381.
    Ciccarelli, Marina
    et al.
    Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
    Straker, Leon
    Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Pollock, Clare
    Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
    Variation in Muscle Activity Among Office Workers When Using Different Information Technologies at Work and Away From Work2013In: Human Factors, ISSN 0018-7208, E-ISSN 1547-8181, Vol. 55, no 5, p. 911-923Article in journal (Refereed)
    Abstract [en]

    Objective: To determine differences in muscle activity amplitudes and variation of amplitudes, when using different Information and Communication Technologies (ICT).

    Background: Office workers use different ICT to perform tasks. Upper body musculoskeletal complaints are frequently reported by this occupational group. Increased muscle activity and insufficient muscle activity variation are potential risk factors for musculoskeletal complaints.

    Method: Muscle activity of right and left upper trapezius and right wrist extensor muscle bundle (extensor carpi radialis longus and brevis) of 24 office workers (performing their usual tasks requiring different ICT at work and away-from-work) were measured continuously over 10-12 hours. Muscle activity variation was quantified using two indices, APDF(90-10) and EVAsd.

    Results: There was a trend for electronics-based New ICT tasks to involve less electromyography (EMG) variation than paper-based Old ICT tasks. Performing Combined ICT tasks (i.e. using paper- and electronics-based ICT simultaneously) resulted in the highest muscle activity levels and least variation; however, these Combined ICT tasks were rarely performed. Tasks involving no ICT (Non-ICT) had the greatest muscle activity variation.

    Conclusion: Office workers in this study used various ICT during tasks at work and away-from-work. The high EMG amplitudes and low variation observed when using Combined ICT may present the greatest risk for musculoskeletal complaints, and use of Combined ICT by workers should be kept low in office work. Breaking up Combined, New and Old ICT tasks; for example, by interspersing highly variable Non-ICT tasks into office workers’ daily tasks, could increase overall muscle activity variation and reduce risk for musculoskeletal complaints.

  • 382.
    Claeson, Anna-Sara
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Andersson, Hanna
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Wikdahl, Fredrik
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Nyback, Maj-Helen
    Nordin, Steven
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Comorbidity of Airway Inflammatory Diseases in Chemical and Building-Related Intolerance2018In: Journal of Occupational and Environmental Medicine, ISSN 1076-2752, E-ISSN 1536-5948, Vol. 60, no 4, p. 295-300Article in journal (Refereed)
    Abstract [en]

    Objectives: This study investigated comorbidity in chemical intolerance (CI) and building- related intolerance (BRI) with (i) chronic sinusitis, chronic obstructive pulmonary disease, allergic and nonallergic asthma and allergic rhinitis, and (ii) airway inflammatory symptoms. Methods: Data from two population-based questionnaire surveys, the Västerbotten and Österbotten Environmental Health Studies, were used. The participants were categorized as CI or BRI and referents, and binary logistic regression analysis was applied. Results: Prevalence rates for the case groups were 7.2% to 40.0% for diseases and 24.3% to 68.9% for symptoms, whereas adjusted odds ratios (ORs) were 3.4 to 26.1 for diseases and 3.3 to 17.0 for symptoms, all being significantly higher than unity. Prevalence rates and ORs were in general higher in BRI than in CI. Conclusion: Inflammatory airway diseases and symptoms are associated with CI and BRI, which encourages further research regarding underlying mechanisms and treatments.

  • 383.
    Claeson, Anna-Sara
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Gouveia-Figueira, Sandra
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Häggström, Jenny
    Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Statistics.
    Fowler, Christopher J.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Pharmacology.
    Nording, Malin L.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Levels of oxylipins, endocannabinoids and related lipids in plasma before and after low-level exposure to acrolein in healthy individuals and individuals with chemical intolerance2017In: Prostaglandins, Leukotrienes and Essential Fatty Acids, ISSN 0952-3278, E-ISSN 1532-2823, Vol. 121, p. 60-67Article in journal (Refereed)
    Abstract [en]

    Oxylipins and endocannabinoids play important biological roles, including effects upon inflammation. It is not known whether the circulating levels of these lipids are affected by inhalation of the environmental pollutant acrolein. In the present study, we have investigated the consequences of low-level exposure to acrolein on oxylipin, endocannabinoid and related lipid levels in the plasma of healthy individuals and individuals with chemical intolerance (CI), an affliction with a suggested inflammatory origin. Participants were exposed twice (60 min) to heptane and a mixture of heptane and acrolein. Blood samples were collected before exposure, after and 24 h post-exposure. There were no overt effects of acrolein exposure on the oxylipin lipidome or endocannibinoids detectable in the bloodstream at the time points investigated. No relationship between basal levels or levels after exposure to acrolein and CI could be identified. This implicates a minor role of inflammatory mediators on the systemic level in CI.

  • 384.
    Claeson, Anna-Sara
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Lidén, Edvard
    Nordin, Maria
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nordin, Steven
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    The role of perceived pollution and health risk perception in annoyance and health symptoms: a population-based study of odorous air pollution2013In: International Archives of Occupational and Environmental Health, ISSN 0340-0131, E-ISSN 1432-1246, Vol. 86, no 3, p. 367-374Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: Health effects associated with air pollution at exposure levels below toxicity may not be directly related to level of exposure, but rather mediated by perception of the air pollution and by top-down processing (e.g., beliefs that the exposure is hazardous). The aim of the study was to test a model that describes interrelations between odorous air pollution at non-toxic exposure levels, perceived pollution, health risk perception, annoyance and health symptoms.

    METHODS: A population-based questionnaire study was conducted in a Swedish community of residents living near a biofuel facility that emitted odorous substances. Individuals aged 18-75 years were selected at random for participation (n = 1,118); 722 (65 %) agreed to participate. Path analyses were performed to test the validity of the model.

    RESULTS: The data support a model proposing that exposure level does not directly influence annoyance and symptoms, and that these relations instead are mediated by perceived pollution and health risk perception.

    CONCLUSIONS: Perceived pollution and health risk perception play important roles in understanding and predicting environmentally induced annoyance and health symptoms in odorous environments at non-toxic levels of exposure.

  • 385.
    Claeson, Anna-Sara
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Lind, Nina
    Swedish Univ Agr Sci, Dept Econ, Uppsala, Sweden.
    Human exposure to acrolein: Time -dependence and individual variation in eye irritation2016In: Environmental Toxicology and Pharmacology, ISSN 1382-6689, E-ISSN 1872-7077, Vol. 45, p. 20-27Article in journal (Refereed)
  • 386.
    Claeson, Anna-Sara
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Lind, Nina
    Department of Economics, Swedish University of Agricultural Science, Uppsala, Sweden.
    Human exposure to acrolein: Time-dependence and individual variation in eye irritation2016In: Environmental Toxicology and Pharmacology, ISSN 1382-6689, E-ISSN 1872-7077, Vol. 45, p. 20-27Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to examine the time dependence on sensory irritation detection following exposure to threshold levels of acrolein, in humans. The exposures occurred in an exposure chamber and the subjects were breathing fresh air through a mask that covered the nose and mouth. All participants participated in four exposure conditions, of which three consisted of a mixture of acrolein and heptane and one of only heptane. Exposure to acrolein at a concentration half of the TLV-C lead to sensory irritation. The perceived sensory irritation resulted in both increased detectability and sensory irritation after about6.8 min of exposure in 58% of the participants. The study confirm the previously suggested LOAEL of about 0.34 mg/m3for eye irritation due to acrolein exposure. The sensory irritation was still significant 10 min after exposure. These results have implications for risk assessment and limit setting in occupational hygiene.

  • 387.
    Claeson, Anna-Sara
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Palmquist, Eva
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Lind, Nina
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Nordin, Steven
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Symptom-trigger factors other than allergens in asthma and allergy2016In: International Journal of Environmental Health Research, ISSN 0960-3123, E-ISSN 1369-1619, Vol. 26, no 4, p. 448-457Article in journal (Refereed)
    Abstract [en]

    Several environmental exposures of particular relevance for indoor air quality, such as exposure to odorants, may be associated with asthma and allergy. The aim of this study was to investigate attribution of symptoms and behavioral disruptions to various chemical and physical environmental sources in persons with self-reported asthma and allergy. Data from a population-based study, the Västerbotten Environmental Health Study, were used to compare persons with asthma, allergic rhinitis, allergic dermatitis, multiple diagnoses of asthma/allergy and no asthma or allergy. Persons with asthma and multiple diagnoses reported odorous/pungent and buildingrelated environmental factors to trigger symptoms to a larger extent than did the reference group, mainly due to perfume and odors from flowers. They also reported behavioral disruptions and affective reactions to odorous/ pungent environments. These findings increase the understanding of the role of odorants in symptom development and thereby the prevention of health problems in asthma and allergy in indoor air.

  • 388.
    Claeson, Anna-Sara
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Palmquist, Eva
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Nordin, Steven
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Physical and chemical trigger factors in environmental intolerance2018In: International journal of hygiene and environmental health (Print), ISSN 1438-4639, E-ISSN 1618-131X, Vol. 221, no 3, p. 586-592Article in journal (Refereed)
    Abstract [en]

    Background: Individuals with environmental intolerance (EI) react to exposure from different environmental sources at levels tolerated by most people and that are below established toxicological and hazardous thresholds. The main aim of this study was to determine the prevalence of attributing symptoms to chemical and physical sources in the environment among individuals with different forms of self-reported EI and in referents.

    Methods: Cross-sectional data from a population-based study, the Västerbotten Environmental Health Study (n = 3406), were used and individuals with self-reported EI to chemicals, buildings, electromagnetic fields and sounds as well as a group with multiple EIs were identified. The Environmental-Symptom Attribution Scale was used to quantify degree to which health symptoms are attributed to 40 specific environmental exposures and sources, with subscales referring to the four types of EI.

    Results: All EI groups, except the group with building related intolerance (BRI), reported more symptoms from the expected sources compared to the referents. In addition, individuals with chemical and sound intolerance reported symptoms from building related trigger factors, and individuals with electromagnetic hypersensitivity reported symptoms from chemical trigger factors.

    Conclusions: The study suggests that individuals with BRI react to fewer and more specific trigger factors than do individuals with other EIs, and that it is important to ask about different sources since three of the EI groups attribute their symptoms to a wide variety of sources in addition to the sources to which their EI implicates.

  • 389.
    Claesson, Maria
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Birgander, Lisbeth Slunga
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Jansson, Jan-Håkan
    Lindahl, B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Burell, G
    Asplund, Kjell
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Mattsson, Cecilia
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Cognitive-behavioural stress management does not improve biological cardiovascular risk indicators in women with ischaemic heart disease: a randomized-controlled trial.2006In: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 260, no 4, p. 320-331Article in journal (Refereed)
  • 390.
    Claesson, Maria
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Slunga Birgander, Lisbeth
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Lindahl, Bernt
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nasic, Salmir
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Åström, Monica
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Asplund, Kjell
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Burell, Gunilla
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Women's hearts - stress management for women with ischemic heart disease: explanatory analyses of a randomized controlled trial.2005In: Journal of Cardiopulmonary Rehabilitation (JCR), ISSN 0883-9212, E-ISSN 1539-0691, Vol. 25, no 2, p. 93-102Article in journal (Refereed)
  • 391.
    Clays, Els
    et al.
    Department of Public Health, Ghent University, Belgium.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Oakman, J.
    Department of Public Health, La Trobe University, Australia.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Objectively measured occupational physical activities in blue collar jobs: do psychosocial resources matter?2017In: European Journal of Preventive Cardiology, ISSN 2047-4873, E-ISSN 2047-4881, Vol. 24, no 2SArticle in journal (Refereed)
    Abstract [en]

    Aim: Occupational physical activity (OPA), and particularly static postures and physically exerting activities, is known to impact worker health and to increase the risk of cardiovascular disease, musculoskeletal problems, sickness absence and premature retirement. The exploration of structural preventive measures at the workplace against the adverse health effects of excessive OPA is needed. The psychosocial work environment is hypothesised to buffer the adverse effects of OPA, and as such psychosocial resources might directly influence the performance of OPA. However, this has not been previously investigated with detailed objective measurements. The aim of this study is to describe OPA within blue-collar workers, and to examine the role of psychosocial job resources in the performance of OPA.

    Methods: Results are based on a sample of 198 blue-collar workers from the NOMAD (New method for Objective Measurements of physical Activity in Daily living) study, recruited from seven workplaces in Denmark. The sample included 112 men (56.6%) and 86 women (43.4%); the mean age was 44.9 years (SD 9.9). Data were collected with two Actigraph devices placed on the thigh and trunk, during four consecutive days. The accelerometer data were processed and analysed using the Acti4 software, to determine working time spent standing, walking, on feet and in activity of moderate to vigorous intensity level (MVPA). The level of influence and social support at work were assessed by questionnaire, and measured with a four-item scale. Analysis of (co-)variance and (multiple) linear regression models were conducted. All analyses were stratified by gender predominance of occupation.

    Results: The different types of OPA significantly varied by particular job type. Within male predominant occupations, job type accounted for 50–70% of explained variance, depending on the type of OPA. Manufacturing workers showed the highest average proportions of working time standing (33%) and on feet (79%), while garbage collectors had the highest proportion of working time in MVPA (33%). Mobile plant operators and construction workers had the lowest average working time spent walking and in MVPA. Differences in OPA between job types in female predominant occupations were less pronounced, but healthcare workers and cleaners had higher average proportions of time spent walking and in MVPA compared to assembly workers. The addition of age and psychosocial resources to the models did not contribute to a larger explained variance in OPA and the relations with job type remained significant. Social support at work showed an independent positive relation with working on feet, and with standing in female predominant jobs only. Influence at work was not related to OPA.

    Conclusion: The positive relation of social support with working on feet and standing is likely to be explained by the nature of the work tasks, as jobs that require these activities probably comprise more close interactions and as such create more intensified levels of cooperation at the work floor. Overall, our hypothesis that psychosocial job resources would affect the performance of OPA within blue-collar workers was not confirmed. These findings suggest that the performance of OPA within blue-collarjobs – and particularly within male predominant occupations – is mostly affected by work organisational factors related to specific job type, and not by psychosocial job resources.

  • 392.
    Clays, Els
    et al.
    Department of Public Health and Primary Care, Ghent University, Belgium.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Oakman, Jodi
    Department of Public Health, Centre for Ergonomics and Human Factors, La Trobe University, Australia.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Objectively measured occupational physical activity in blue-collar workers: What is the role of job type, gender and psychosocial resources?2019In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 82, article id 102948Article in journal (Refereed)
    Abstract [en]

    The aim was to describe occupational physical activity (OPA) and examine the role of psychosocial job resources among blue-collar workers. In a sample of 198 workers (57% male; mean age 44.9 (SD 9.9) year) from 7 companies in Denmark, two accelerometers (Actigraph) were placed on the thigh and trunk during 1-5 consecutive days, to determine working time spent standing, walking, on feet and in activity of moderate to vigorous intensity level (MVPA). The level of influence and social support at work were assessed by questionnaire. The exposure to OPA significantly varied by particular job type, especially in male predominant occupations. Overall, psychosocial job resources did not affect the exposure to OPA. These findings suggest that workplace interventions aiming to prevent adverse outcomes of OPA among blue-collars workers ought to focus on task redesign and target work organizational factors related to specific job type.

  • 393. Clendenen, Tess V.
    et al.
    Arslan, Alan A.
    Lokshin, Anna E.
    Liu, Mengling
    Lundin, Eva
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Koenig, Karen L.
    Berrino, Franco
    Hallmans, Göran
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Nutritional Research. Umeå University, Faculty of Medicine, Department of Biobank Research.
    Idahl, Annika
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Krogh, Vittorio
    Lukanova, Annekatrin
    Marrangoni, Adele
    Muti, Paola
    Nolen, Brian M.
    Ohlson, Nina
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Shore, Roy E.
    Sieri, Sabina
    Zeleniuch-Jacquotte, Anne
    Circulating prolactin levels and risk of epithelial ovarian cancer2013In: Cancer Causes and Control, ISSN 0957-5243, E-ISSN 1573-7225, Vol. 24, no 4, p. 741-748Article in journal (Refereed)
    Abstract [en]

    Indirect evidence from experimental and epidemiological studies suggests that prolactin may be involved in ovarian cancer development. However, the relationship between circulating prolactin levels and risk of ovarian cancer is unknown.

    We conducted a nested case-control study of 230 cases and 432 individually matched controls within three prospective cohorts to evaluate whether pre-diagnostic circulating prolactin is associated with subsequent risk of ovarian cancer. We also assessed whether lifestyle and reproductive factors are associated with circulating prolactin among controls.

    Prolactin levels were significantly lower among post- versus pre-menopausal women, parous versus nulliparous women, and past versus never users of oral contraceptives in our cross-sectional analysis of controls. In our nested case-control study, we observed a non-significant positive association between circulating prolactin and ovarian cancer risk (ORQ4vsQ1 1.56, 95 % CI 0.94, 2.63, p trend 0.15). Our findings were similar in multivariate-adjusted models and in the subgroup of women who donated blood a parts per thousand yen5 years prior to diagnosis. We observed a significant positive association between prolactin and risk for the subgroup of women with BMI a parts per thousand yen25 kg/m(2) (ORQ4vsQ1 3.10, 95 % CI 1.39, 6.90), but not for women with BMI < 25 kg/m(2) (ORQ4vsQ1 0.81, 95 % CI 0.40, 1.64).

    Our findings suggest that prolactin may be associated with increased risk of ovarian cancer, particularly in overweight/obese women. Factors associated with reduced risk of ovarian cancer, such as parity and use of oral contraceptives, were associated with lower prolactin levels, which suggests that modulation of prolactin may be a mechanism underlying their association with risk.

  • 394.
    Coenen, Pieter
    et al.
    School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia; Department of Public and Occupational Health, Amsterdam Public Health Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
    Korshøj, Mette
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Hallman, David M.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Huysmans, Maaike A.
    Department of Public and Occupational Health, Amsterdam Public Health Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
    van der Beek, Allard J.
    Department of Public and Occupational Health, Amsterdam Public Health Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
    Straker, Leon M
    School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark; Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
    Differences in heart rate reserve of similar physical activities during work and in leisure time - A study among Danish blue-collar workers2018In: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 185, p. 45-51Article in journal (Refereed)
    Abstract [en]

    Recent studies suggest that while leisure-time physical activity (LTPA) promotes general health, engaging in occupational physical activity (OPA) may have negative health consequences. It has been hypothesized that the different health effects from OPA and LTPA can be explained by differences in physical activity (PA) intensity in these two domains. To assess the intensity of OPA and LTPA, we aimed to study the percentage heart rate reserve (%HRR) during similar types of OPA and LTPA during workdays. Data from the NOMAD study on Danish blue-collar workers (n=124) with objective measurements of PA (using accelerometers) and heart rate (using heart rate monitors) for 4 workdays were analysed. Activities of sitting, standing, moving, walking, and stair climbing were identified and %HRR in each of these activities was determined for work and leisure. %HRR was significantly higher during OPA than LTPA. These differences were more pronounced in men than in women. Although not statistically significant in the fully adjusted model, we found indications that these differences were more pronounced in those with low compared to high fitness. To our knowledge, this is the first study with objective measurements showing that %HRR is higher during the same gross-body postural activities when performed at work compared to leisure-time during workdays. This elevated intensity may help explaining the negative health consequences of engagement in high levels of OPA. Future guidelines should distinguish OPA from LTPA, possibly by advising workers to remain active during their leisure time, in particular when they are highly active at work.

  • 395.
    Coenen, Pieter
    et al.
    Department of Public and Occupational Health, VU University Medical Center, The Netherlands.
    Korshøj, Mette
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    van der Beek, Allard
    Department of Public and Occupational Health, VU University Medical Center, The Netherlands.
    Straker, Leon
    School of Physiotherapy and Exercise Science, Curtin.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Differences in heart rate reserve during occupational and leisure time physical activity in Danish blue-collar workers2017In: European Journal of Preventive Cardiology, ISSN 2047-4873, E-ISSN 2047-4881, Vol. 24, no 2S, p. 33-34Article in journal (Refereed)
    Abstract [en]

    Aim: Physical activity (PA) is considered to be an important factor in the prevention of various cardiovascular diseases. However, recent studies suggest that while leisure time PA promotes cardiovascular health, occupational PA might impair cardiovascular health. An explanation for this PA health paradox may be a difference in the intensity and associated physical demands between occupational and leisure time PA. Occupational PA often consists of low-intensity, long-lasting physically demanding tasks, such as repetitive work and prolonged static working postures, which are presumed to cause sustained elevated heart rate that may stress the cardiovascular system. Despite this notion, the differences in physiological responses between occupational and leisure time PA are not well understood. Therefore, we aimed: (a) to study the difference in intensity of occupational and leisure time PA (expressed in percentage heart rate reserve; % HRR); and b) to assess whether this potential difference varies by gender and cardiorespiratory fitness level.

    Methods: We used data from the NOMAD study, in which Danish blue-collar workers from seven different workplaces took part in a four-day protocol of objective measurements of PA (using hip and thigh-worn accelerometers) and heart rate (using an ambulatory heart rate monitor). During occupational and leisure time, activities of sitting, standing, moving, walking and stair climbing were identified, and %HRR in each of these activities was determined. Differences in %HRR between occupational and leisure time PA were tested using generalised estimating equations (expressed in regression coefficient – beta with 95% confidence interval (CI)) adjusted for personal, health,work and lifestyle confounders.

    Result: In 124 workers with data on PA and heart rate, %HRR was higher for occupational PA compared to leisure time PA (beta1.9, 95% CI2.4,1.4,P<0.001). Differences in %HRR between occupational and leisure time PA were more pronounced in men than in women, and in those with high cardiorespiratory fitness compared to those with low cardiorespiratory fitness.

    Conclusion: This study is the first to assess differences in %HRR between occupational and leisure time PA, using objectiv emeasurements in blue-collarworkers. Cardiovascular intensity was higher in occupational activities (possibly due to additional physical and/or mental workloads) compared to the same activities during leisure time. The increase in cardiovascular intensity at work maybe a contributing factor to the health paradox of occupational and leisure time PA, suggesting negative cardiovascular health consequences for engagement in occupational PA (see Figure 1).

  • 396.
    Coenen, Pieter
    et al.
    Curtin University, Perth, Australia; VU University Amsterdam, the Netherlands; Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    VU University Amsterdam, the Netherlands; Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands.
    Boot, Cécile
    Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands; EMGO Institute, VU University Medical Center, Amsterdam, the Netherlands.
    Bongers, Paulien
    Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands; TNO Healthy Living, Hoofddorp, the Netherlands.
    van Dieën, Jaap
    VU University Amsterdam, the Netherlands; King Abdulaziz University,Jeddah, Saudi Arabia.
    Bias and power in group-based epidemiologic studies of low-back pain exposure and outcome: effects of study size and exposure measurement efforts2015In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 59, no 4, p. 439-454Article in journal (Refereed)
    Abstract [en]

    Objectives: Exposure-outcome studies, for instance on work-related low-back pain (LBP), often classify workers into groups for which exposures are estimated from measurements on a sample of workers within or outside the specific study. The present study investigated the influence on bias and power in exposure-outcome associations of the sizes of the total study population and the sample used to estimate exposures.

    Methods: At baseline, lifting, trunk flexion, and trunk rotation were observed for 371 of 1131 workers allocated to 19 a-priori defined occupational groups. LBP (dichotomous) was reported by all workers during three years of follow-up. All three exposures were associated with LBP in this parent study (p<0.01).

    All 21 combinations of n=10,20,30 workers per group with an outcome, and k=1,2,3,5,10,15,20 workers actually being observed were investigated using bootstrapping, repeating each combination 10,000 times. Odds ratios (OR) with p-values were determined for each of these virtual studies. Average OR and statistical power (p<0.05 and p<0.01) was determined from the bootstrap distributions at each (n,k) combination.

    Results: For lifting and flexed trunk, studies including n≥20 workers, with k≥5 observed, led to an almost unbiased OR and a power >0.80 (p-level 0.05). A similar performance required n≥30 workers for rotated trunk. Small numbers of observed workers (k) resulted in biased OR, while power was, in general, more sensitive to the total number of workers (n).

    Conclusions: In epidemiologic studies using a group-based exposure assessment strategy, statistical performance may be sufficient if outcome is obtained from a reasonably large number of workers, even if exposure is estimated from only few workers per group.

  • 397.
    Coenen, Pieter
    et al.
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Boot, Cécile
    Body@Work, Research Center on Physical Activity, Work and Health, The Netherlands.
    Bongers, Paulien
    Body@Work, Research Center on Physical Activity, Work and Health, The Netherlands.
    van Dieën, Jaap
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Group-based exposuremeasurement strategies and their effects on trunk rotation and low-back pain exposure-outcome associations2013In: Occupational & Environmental Medicine: 23rd Conference on Epidemiology in Occupational Health EPICOH 2013: Improving the Impact June 18–21, 2013, Utrecht, The Netherlands, BMJ Journals , 2013, p. A101-A102Conference paper (Refereed)
    Abstract [en]

    Objectives In epidemiological studies of occupational exposures (e.g. lifting) and low-back pain (LBP), group-based exposure measurement strategies are common. Workers are classified into exposure groups; exposure is measured only in a selection of workers in each group, and their mean exposure is assigned to all workers in the group. Exposure-outcome relationships are then determined by regression, relating exposure estimates with individual LBP data from all subjects. The objective of this study was to assess the effect of different group-based measurement strategies on exposure-outcome associations.

    Methods 1122 workers, classified into 19 groups on the basis of job-related exposure, participated in this study. In each group, videos were collected from ~25% of the workers (in total, 370 workers), and percentage of the work day spent in trunk rotation was estimated by observation of the videos. This estimate of trunk rotation was significantly associated with self-reported LBP during three years of follow-up (OR:1.43 (1.06–1.93)).

    Using a bootstrap simulation, workers per group (n = 10, 20, 30, 40) and percentage of observed workers (k = 10, 20, 30, 40, 50%) were varied. For each combination, (nk) workers were selected with replacement in each job group among those observed, and n (100-k) workers among those not observed. The mean exposure of the observed workers was assigned to all group members which was related to individual LBP data. ORs and accompanying p-level was estimated using logistic-regression.

    Results A group-based measurement protocol led to significant (p < 0.05) ORs when the total number of workers was larger than n = 30 in each job group, and ≥20% was actually observed.

    Conclusions The proportion of observed workers did have an effect on p-values, but it appeared weaker than that of changing the total group size. These results suggest that it may be sufficient to observe only a minor proportion of workers if the overall size of the population is reasonably large.

  • 398.
    Coenen, Pieter
    et al.
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Boot, Cécile
    Body@Work, Research Center on Physical Activity, Work and Health, The Netherlands.
    Bongers, Paulien
    Body@Work, Research Center on Physical Activity, Work and Health, The Netherlands.
    van Dieën, Jaap
    Faculty of Human Movement Sciences, VU University Amsterdam.
    The effect of group-based exposure measurement strategies on the statistical significance of an association between lifting and low-back pain2013In: Eighth International Conference on Prevention of Work-related Musculoskeletal Disorders; Abstracts, 2013, p. 175-Conference paper (Refereed)
  • 399.
    Coenen, Pieter
    et al.
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Boot, Cécile
    EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam.
    Bongers, Paulien
    TNO Healthy Living, Hoofddorp.
    van Dieën, Jaap
    Faculty of Human Movement Sciences, VU University Amsterdam.
    The effect of the presence and characteristics of an outlying group on exposure-outcome associations2015In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 41, no 1, p. 65-74Article in journal (Refereed)
    Abstract [en]

    Objectives: Physical exposures (e.g., lifting or bending) are believed to be risk factors for low-back pain (LBP), but the literature is inconsistent. Exposure and LBP prevalence differ considerably between occupations, and so exposure-outcome associations could be severely modified by the presence of particular occupational groups. We aimed at investigating the influence of such outlying groups on the properties of associations between exposure and LBP.

    Methods: Lifting and trunk flexion were observed for 371 of 1131 workers within 19 groups. LBP was obtained from all workers during three follow-up years. Both exposure variables were associated with LBP (p<0.01) in this parent dataset.

    By removing the 19 groups one-by-one and performing logistic regressions analysis on the 18 remaining groups, we demonstrated that one group, mainly road workers, with outlying exposures and LBP prevalence substantially affected the exposure-outcome association in the total population. In order to further examine this phenomenon, we assessed, by simulation, the influence of realistic sizes (n=4, 8, 16, 32, 64, 128), mean exposures (e=2000, 3000, 4000 lifts and e=30, 40, 50% trunk flexion time) and LBP prevalences (p=70, 80, 90, 100%) of the outlying group on the strength and certainty of the eventual relationship between exposure and LBP. For each combination of n, e and p, 3000 virtual studies were constructed, including the simulated group together with the other 18 original groups from the parent data-set. Average OR, OR confidence limits, and power (p<0.05) were calculated across these 3,000 studies as measures of the properties of each virtual study design.

    Results: ORs were attenuated more towards 1 and power decreased with smaller values of n, e and p in the outlying group. Changes in group size and prevalence had a larger influence on OR and power than changes in mean exposure.

    Conclusions: The size and characteristics of a single group with high exposure and outcome prevalence can strongly influence both the OR point estimate and the likelihood of obtaining significant exposure-outcome associations in studies of large populations. These findings can guide interpretations of prior epidemiological studies and support informed design of future studies.

  • 400.
    Coenen, Pieter
    et al.
    Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    van der Beek, Allard
    Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Correction of bias in self-reported sitting time among office workers – a study based on compositional data analysis2019In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990XArticle in journal (Refereed)
    Abstract [en]

    Objective: Emerging evidence suggests that excessive sitting has negative health effects. However, this evidence largely relies on research using self-reported sitting time, which is known to be biased. To correct this bias, we aimed at developing a calibration model estimating "true" sitting from self-reported sitting.

    Methods: Occupational sitting time was estimated by self-reports (the International Physical Activity Questionnaire) and objective measurements (thigh-worn accelerometer) among 99 Swedish office workers at a governmental agency, at baseline and 3 and 12 months afterwards. Following compositional data analysis procedures, both sitting estimates were transformed into isometric log-ratios (ILR). This effectively addresses that times spent in various activities are inherently dependent and can be presented as values of only 0−100%. Linear regression was used to develop a simple calibration model estimating objectively measured "true" sitting ILR (dependent variable) from self-reported sitting ILR (independent variable). Additional self-reported variables were then added to construct a full calibration model. Performance of the models was assessed by root-mean-square (RMS) differences between estimated and objectively measured values. Models developed on baseline data were validated using the follow-up datasets.

    Results: Uncalibrated self-reported sitting ILR showed an RMS error of 0.767. Simple and full calibration models (incorporating body mass index, office type, and gender) reduced this error to 0.422 (55%) and 0.398 (52%), respectively. In the validations, model performance decreased to 57%/62% (simple models) and 57%/62% (full models) for the two follow-up data sets, respectively.

    Conclusions: Calibration adjusting for errors in self-reported sitting led to substantially more correct estimates of "true" sitting than uncalibrated self-reports. Validation indicated that model performance would change somewhat in new datasets and that full models perform no better than simple models, but calibration remained effective.

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