| 1. |
- Cillekens, Bart, et al.
(författare)
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O7-1 The association of occupational and leisure time physical activity with all-cause mortality. Using an individual participant dataset (N = 634,131)
- 2022
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Ingår i: European Journal of Public Health. - : Oxford Academic. - 1101-1262 .- 1464-360X. ; 32:Suppl2
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPhysical activity is a key determinant for health and considered as an important factor in the prevention of lifestyle related-diseases. All physical activity domains are generally considered to be health enhancing. However, accumulating evidence in recent years suggests that occupational physical activity may not have the same beneficial health effect as leisure time physical activity. Our aim was to assess the association of occupational and leisure time physical activity and all-cause mortality.MethodsWe obtained individual participant data from published and unpublished cohort studies and assessed their risk of bias. We harmonized the data, and used Cox survival regression models to assess the association between occupational and leisure time physical activity with all-cause mortality, in a two-stage individual participant data meta-analysis. Different models were performed to assess the impact of relevant confounders including behavioral, health-related and socio-economic factors. Results of the data were reported with hazard ratios (HRs) and 95% confidence intervals (95% CI).ResultsData from 22 prospective cohort studies showed that male workers with high occupational physical activity had an increased risk of all-cause mortality in comparison with sedentary occupational physical activity (HR: 1.12, 95%CI: 1.03- 1.23). For female workers, no such association was found (HR: 1.01, 95%CI: 0.85-1.19). when comparing high with sedentary occupational physical activity.Increasing levels of leisure time physical activity were inversely and dose-dependently associated with a reduced risk of all-cause mortality. For example, high compared with sedentary leisure time physical activity was associated with reduced risks for males (HR: 0.53, 95%CI: 0.36-0.79) and for females (HR: 0.49, 95%CI: 0.31-0.79).All associations remained robust when adjusting for additional relevant confounders, leaving one study out analysis, and when assessing the role of bias and reverse causality.ConclusionWe consistently found a reduced risk of all-cause mortality with increasing levels of leisure time physical activity, but not for occupational physical activity. These findings indicate that occupational activity may not be health-enhancing. These findings suggest that occupational physical activity may not be considered a suitable substitute to leisure time physical activity when striving for health enhancement.
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| 2. |
- Coenen, Pieter, et al.
(författare)
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Bias and power in group-based epidemiologic studies of low-back pain exposure and outcome : effects of study size and exposure measurement efforts
- 2015
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 59:4, s. 439-454
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Coenen, Pieter, et al.
(författare)
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Calibration of self-reported physical behaviours among office workers: A compositional data analysis
- 2019
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Ingår i: ICAMPAM 2019. - Maastricht : ICAMPAM.
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Konferensbidrag (refereegranskat)abstract
- The aim of this study was to develop and evaluate calibration models to predict objectively measured time spent sitting, standing and walking during office work from self-reported time-use compositions using a compositional data analysis (CoDA) approach. Ninety-nine office workers (49 women) at the Swedish Transport Administration participated in an intervention study on relocation to activity-based offices. At baseline and at a 3-months follow-up, physical behaviours (sitting, standing and walking) at work were assessed for five days using a thigh-mounted accelerometer (Actigraph) and by self-report (IPAQ). The time-use composition of the three behaviours was expressed in terms of isometric log-ratios (ILR). Calibration models predicting accelerometry-based time-use from self-reported compositions were constructed using linear regression on baseline data, and then validated using follow-up data. The accelerometer data showed that, on average, workers spent 69.9% of their day sitting, 23.7% standing, and 6.4% walking. The corresponding percentages for self-reports were 71.7%, 21.6%, and 7.4%, respectively. Non-calibrated self-reports were biased: the RMS errors obtained from the ILRs expressing sitting, standing and walking were 0.73, 1.09 and 1.05, respectively. Calibration models reduced these errors by 45% (sitting), 56% (standing), and 76% (walking). Validation of the calibration models using follow-up data from the same workers showed calibration remained equally effective; RMS errors were reduced by 55% (sitting), 58% (standing), and 75% (walking). In conclusion, calibration models for compositional time-use data were effective in reducing bias in self-reported physical behaviours at work, and the models remained effective when used on new data from the same workers. Calibrated self-reports may represent a cost-effective method for obtaining physical behaviour data with a satisfying accuracy in large-scale cohort and intervention studies.
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| 4. |
- Coenen, Pieter, et al.
(författare)
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Correction of bias in self-reported sitting time among office workers – a study based on compositional data analysis
- 2020
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 46:1, s. 32-42
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Tidskriftsartikel (refereegranskat)abstract
- 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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| 5. |
- Coenen, Pieter, et al.
(författare)
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Differences in heart rate reserve during occupational and leisure time physical activity in Danish blue-collar workers
- 2017
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Ingår i: European Journal of Preventive Cardiology. - : Sage Publications. - 2047-4873 .- 2047-4881. ; 24:2S, s. 33-34
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Tidskriftsartikel (refereegranskat)abstract
- 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).
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| 6. |
- Coenen, Pieter, et al.
(författare)
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Differences in heart rate reserve of similar physical activities during work and in leisure time - A study among Danish blue-collar workers
- 2018
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 185, s. 45-51
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Coenen, Pieter, et al.
(författare)
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Group-based exposuremeasurement strategies and their effects on trunk rotation and low-back pain exposure-outcome associations
- 2013
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Ingår i: Occupational & Environmental Medicine. - : BMJ Journals. ; , s. A101-A102
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 8. |
- Coenen, Pieter, et al.
(författare)
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The association of adolescent spinal-pain-related absenteeism with early adulthood work absenteeism : A six-year follow-up data from a population-based cohort
- 2018
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Nordic Association of Occupational Safety and Health. - 0355-3140 .- 1795-990X. ; 44:5, s. 521-529
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Spinal (ie, back and neck) pain often develops as early as during adolescence and can set a trajectory for later life. However, whether early-life spinal-pain-related behavioral responses of missing school/work are predictive of future work absenteeism is yet unknown. We assessed the association of adolescent spinal-pain-related work or school absenteeism with early adulthood work absenteeism in a prospective population-based cohort.Methods: Six year follow-up data from the Western Australian Pregnancy Cohort (Raine) study were used (N=476; with a 54% response rate). At age 17, participants reported spinal pain (using the Nordic questionnaire) and adolescent spinal-pain-related work/school absenteeism (with a single item question). Annual total and health-related work absenteeism was assessed with the Health and Work Performance questionnaire distributed in four quarterly text messages during the 23rd year of age. We modelled the association of adolescent spinal-pain-related absenteeism with work absenteeism during early adulthood, using negative binomial regression adjusting for sex, occupation and comorbidities.Results: Participants with adolescent low-back or neck pain with work/school absenteeism reported higher total work absenteeism in early adulthood [148.7, standard deviation (SD) 243.4 hours/year], than those without pain [43.7 (SD 95.2) hours/year); incidence rate ratio 3.4 (95% CI 1.2-9.2)]. Comparable findings were found when considering low-back and neck separately, and when considering health-related absenteeism.Conclusions: We found a more than three-fold higher risk of work absenteeism in early adulthood among those with adolescent spinal-pain-related absenteeism, compared to those without. These findings suggest that, to keep a sustainable workforce, pain prevention and management should focus on pain-related behaviors as early as in adolescence.
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| 9. |
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| 10. |
- Coenen, Pieter, et al.
(författare)
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The effect of the presence and characteristics of an outlying group on exposure-outcome associations
- 2015
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 41:1, s. 65-74
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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