Danish Work Environment Cohort Study Research Articles

Towards an assessment of psychosocial work factors in a multi-level mental health intervention in the workplace: results from the MENTUPP pilot-study.

Mental health in the workplace is a growing concern for enterprises and policy makers. MENTUPP is a multi-level mental health intervention implemented in small and medium size enterprises from three work sectors in nine countries. This pilot study aimed to evaluate the feasibility, delivery, and instruments for the MENTUPP intervention to inform the planning of a clustered randomized controlled trial. We administered items from the Copenhagen Psychosocial Questionnaire and the Danish Work Environment Cohort Study measuring psychosocial workplace factors. The questionnaire was answered by 382 participants at baseline, of which 98 participants also answered after six months at follow-up. We calculated mean scores of 19 psychosocial factors at baseline and conducted repeated measures ANOVAs to assess differences in eight psychosocial factors at follow-up. We also examined whether outcomes differed between work sectors and job positions at follow-up. The construction sector and workers with no or a lower leadership role reported more negative working environment factors at baseline. We observed a statistically significant decline in social support from colleagues and social community at work, and a marginally significant decline in justice at work. For the rest of the constructs, we did not observe statistically significant changes. We found significant differences in psychosocial work environment factors among work sectors and job positions at baseline. Contrary to our hypotheses, three psychosocial work environment factors decreased at follow-up. Possible explanations are the utilization of specific psychosocial factors as resources to cope with psychosocial stressors, high participant expectations that were not met by the intervention, insufficient time for structural changes, or the intervention prompting critical evaluations of the work environment. These findings will inform the design and implementation of the forthcoming clustered randomized controlled trial, where they will also be further investigated to validate their significance.

Workplace Violence and Long-term Sickness Absence: Assessment of the Potential Buffering Effect of Social Support in Two Occupational Cohort Studies.

We aimed to determine the effect of workplace violence on long-term sickness absence, and whether social support from supervisors and colleagues buffer this effect. Information on workplace violence and social support were derived from the Danish Work Environment Cohort Study in 2000, 2005, and 2010 and the Swedish Longitudinal Occupational Survey of Health in 2006 and 2008. Individual- and joint-effects on register-based long-term sickness absence were determined using logistic regression models for repeated measurements. Cohort-specific estimates were combined in random effect meta-analyses. Workplace violence and low social support were independently associated with a higher risk of long-term sickness absence, and we did not find evidence of an interaction. Exposure to workplace violence is a risk factor for long-term sickness absence while social support is associated with a lower risk of long-term sickness absence.

Does Midlife Forgetfulness Influence Positive and Negative Aspects of Social Relations at Work?: Results From the Danish Working Environment Cohort Study.

We investigated whether midlife forgetfulness was prospectively associated with changes in social relations at work (SRW) among occupationally active individuals in Denmark. We analyzed data of 2339 men and women participating in the first (1990) and second (1995) survey of the Danish Work Environment Cohort Study, responding to questions on working environment, SRW, and forgetfulness. We used multiple linear regression analysis while adjusting for potential confounders. At baseline (1990), 517 (22.1%) study participants were categorized as forgetful. Forgetfulness was prospectively associated with a decline in one of the investigated items reflecting a negative aspect of SRW (experiencing teasing, regression coefficient = 0.07, 95% CI: 0.03 to 0.11), while no association was observed with positive aspects of SRW. Our findings did not support the hypothesis that memory problems such as midlife forgetfulness negatively affect SRW.

Joint association of physical and psychosocial working conditions with risk of long-term sickness absence: Prospective cohort study with register follow-up

Aims: The interplay between physical and psychosocial working conditions for the risk of developing poor health is not well understood. This study aimed to determine the joint association of physical and psychosocial working conditions with risk of long-term sickness absence (LTSA) in the general working population. Methods: Based on questionnaire responses about physical working conditions and psychosocial working conditions (influence at work, emotional demands, support from colleagues and support from managers) and two-year prospective follow-up in a national register on social transfer payments, we estimated the risk of incident LTSA of >30 days among 9544 employees without previous LTSA from the Danish Work Environment Cohort Study. The analyses were censored for all events of permanent labour market drop-out (retirement, disability pension, immigration or death) and controlled for potential confounders. Results: In the total cohort, more demanding physical working conditions were associated with risk of LTSA in a dose-response fashion (trend test, p<0.0001). The combination of poor overall psychosocial working conditions (index measure of influence at work, emotional demands, support from managers and support from colleagues) and hard physical working conditions showed the highest risk of LTSA. However, poor overall psychosocial working conditions did not interact with physical working conditions in the risk of LTSA (p=0.9677). Conclusions: The results of this study suggest that workplaces should strive to improve both psychosocial and physical work factors in order to ensure the health of workers.

Association between physical work demands and work ability in workers with musculoskeletal pain: cross-sectional study

BackgroundMusculoskeletal pain is common in the working population and may affect the work ability, especially among those with high physical work demands. This study investigated the association between physical work demands and work ability in workers with musculoskeletal pain.MethodsWorkers with physically demanding jobs (n = 5377) participated in the Danish Work Environment Cohort Study in 2010. Associations between physical work ability and various physical work demands were modeled using cumulative logistic regression analyses while controlling for possible confounders.ResultsIn the fully adjusted model, bending and twisting/turning of the back more than a quarter of the workday (reference: less than a quarter of the workday) was associated with higher odds of lower work ability in workers with low-back pain (OR: 1.38, 95% CI: 1.09–1.74) and neck-shoulder pain (OR: 1.29, 95% CI: 1.01–1.64). When adding up the different types of demands, being exposed to two or more physical work demands for more than a quarter of the workday was consistently associated with lower work ability.ConclusionsWork that involves high demands of the lower back seems especially problematic in relation to work ability among physical workers with musculoskeletal pain. Regardless of the specific type of physical work demand, being exposed to multiple physical work demands for more than a quarter of the workday was also associated with lower work ability.

High leisure-time physical activity reduces the risk of long-term sickness absence.

This study examined the association of leisure-time physical activity (LTPA) with the risk of long-term sickness absence (LTSA). A total of 10427 subjects from the general working population in Denmark answered questions about physical activity habits, health and work environment in the 2010 Danish Work Environment Cohort Study (DWECS). Data on LTSA (≥6 consecutive weeks during 2-year follow-up) were obtained from the Danish Register for Evaluation of Marginalization (DREAM). Cox regression analysis censored for competing events and adjusted for potential confounders (age, sex, BMI, smoking habits, depression, cancer, back diseases, previous LTSA, occupational social class, and psychosocial work environment) estimated the association between the predictor (LTPA) and the outcome variable (LTSA). During the 2-year follow-up period, 9.2% of the studied population experienced LTSA. In the general working population, moderate LTPA was not associated with LTSA (HR=0.89, 95% CI: 0.72-1.09), while high LTPA showed a tendency (HR=0.77, 95% CI: 0.59-1.01). In subgroup analyses, women below the age of 45years with high LTPA showed a significantly lower risk of LTSA when compared with their low LTPA counterparts (HR=0.44, 95% CI: 0.25-0.78). The results suggest that high levels of physical activity during leisure are associated with a lowered risk of LTSA, especially among younger women.

Job control and risk of disability pension in the nationwide Danish Work Life Course Cohort

Abstract Background A large number of studies have found job control to be consistently associated with an increased risk of disability pension. However, most previous studies have measured job control by self-report, introducing possible reporting bias inflating the risk estimates. Furthermore, previous studies have not accounted for the potential selection of individuals with pre-existing risk factors for disability pensioning into low control jobs. Methods We analyzed data from the nationwide register-based Danish Work Life Course Cohort (DAWCO; n = 960,562 with approx. 6 million person-years). We measured job control annually by a job exposure matrix, based on a scale of five self-reported items from The Danish Work Environment Cohort Study, and disability pension using registers on public transfer payments. To account for potential selection into occupations with lower levels of job control, we included numerous life course confounders, including parental socioeconomic position and psychiatric and somatic diagnoses. Results Employees in jobs with lower levels of job control had increased risk of disability pensioning. The association attenuated after adjustment for confounders but was not explained by selection into job groups with lower levels of job control (hazard ratio: 1.16 (95% CI: 1.03-1.31). Conclusions Our findings suggest that lower levels of job control are associated with an increased risk of disability pension, and that this association is explained by neither reporting bias nor a selection of individuals with an increased risk of disability pensioning into job groups with lower levels of job control. Key messages Lower levels of job control appear associated with an increased risk of disability pension independent of life course confounders. Further research is needed on preventive measures in occupations with low levels of job control.

Midlife Forgetfulness and Risk of Dementia in Old Age: Results from the Danish Working Environment Cohort Study

Background: Despite the current evidence of a high prevalence of forgetfulness in middle-aged individuals, and the evidence of a link between midlife memory complaints and biological changes in the brain, no previous study has yet investigated midlife forgetfulness in relation to risk of dementia in old age. Aims: We investigated whether midlife forgetfulness was an indicator of an increased risk of dementia in old age. Methods: We used data from 3,136 employed men and women who participated in the Danish Work Environment Cohort Study in 1990. These data were linked to Danish national registers. Participants were asked whether their closest relative had ever told them that they were forgetful. Incidence rate ratios (IRR) were estimated using Poisson regression analysis. Results: At baseline, 749 (24%) study participants were categorized as forgetful, and 86 (2.7%) participants were diagnosed with dementia during a total of 31,724 person-years at risk. After adjusting for sociodemographic factors, comorbidities, and work-related factors, midlife forgetfulness was associated with a higher risk of dementia (IRR = 1.82; 95% CI: 1.12–2.97). Conclusions: This study is the first to investigate midlife forgetfulness and dementia, and the results suggest that midlife forgetfulness is an early indicator of an increased risk of dementia in old age.

Are Insomnia Type Sleep Problems Associated With a Less Physically Active Lifestyle? A Cross-Sectional Study Among 7,700 Adults From the General Working Population.

Background: Sleep problems are common in the general population and negatively affect both private and work life. A vicious circle may exist between poor sleep and an unhealthy lifestyle. For example, poor sleep may drain the energy to do health-promoting physical activity during leisure-time after work. The aim of the present study was to investigate the association between sleep problems and the duration of low- and high-intensity leisure-time physical activity in sedentary and physical workers.Methods: This cross-sectional study employ data from the Danish Work Environment Cohort Study in 2010, where currently employed wage-earners in Denmark on daytime schedule (N = 7,706) replied to questions about sleep quality (cf. the Bergen Insomnia Scale) and participation in low- and high-intensity leisure-time physical activity. Associations were modeled using general linear models controlling for various confounders.Results: Workers with high levels of sleep problems reported less high-intensity leisure-time physical activity. Specifically, the weekly duration of high-intensity leisure-time physical activity was 139 (95%CI 111–168), 129 (95%CI 101–158), and 122 (95%CI 92–151) min in sedentary workers with sleep problems < 1, 1–3, and ≥3 days per week, respectively. The same pattern was observed among physical workers. In sedentary workers ≥50 years, the fully adjusted model showed a weekly duration in high-intensity physical activity during leisure of 122 (95%CI 83–161), 102 (95%CI 64–141), and 90 (95%CI 51–130) among those with sleep problems < 1, 1–3, and ≥3 days per week, respectively.Conclusions: Workers, particularly sedentary older workers, having sleep problems report less high-intensity leisure-time physical activity. These data suggest that a vicious circle may indeed exist between poor sleep and reduced leisure-time physical activity.

Physical workload and bodily fatigue after work: cross-sectional study among 5000 workers.

BackgroundPersistent bodily fatigue after working days may indicate an imbalance between work demands and capacity of the workers. This study aimed to investigate associations between physical exposures at work and bodily fatigue after work.MethodsDanish workers with physical work (N=5377) answered questions about various physical exposures during work and bodily fatigue after work in the 2010 round of the Danish Work Environment Cohort Study. Associations were modeled using binary logistic regression controlled for various confounders.ResultsMean age among the younger (<50 years) and older (≥50 years) workers was 36 and 56 years, respectively. Younger and older workers exposed to various physical exposures (e.g. ‘bending/twisting the back’) for more than a quarter of the workday were more fatigued after work. An exposure–response relationship was observed between the number of physical exposures and bodily fatigue, with odds ratios (OR) for fatigue in the body among younger workers being 1.01 (95%CI 0.63–1.63), 1.59 (95%CI 1.01–2.50), 2.37 (95%CI 1.54–3.66) and 2.84 (95%CI 1.85–5.36) for 1, 2, 3 and ≥4 types of combined physical exposures, respectively. Correspondingly, for older workers, ORs were 1.95 (95%CI 1.09–3.51), 4.06 (95%CI 2.32–7.12), 4.10 (95%CI 2.28–7.37) and 4.90 (95%CI 2.72–8.82) for 1, 2, 3 and ≥4 exposures, respectively.ConclusionWhile some of the single factor exposures were associated with increased bodily fatigue, the most marked associations were found when summing the number of different exposures. These results indicate that workplaces should focus on the sum of combined physical exposures rather than focusing solely on single exposures.

Fear Avoidance Beliefs and Risk of Long-Term Sickness Absence: Prospective Cohort Study among Workers with Musculoskeletal Pain.

Background and Objective Musculoskeletal pain is common in the population. Negative beliefs about musculoskeletal pain and physical activity may lead to avoidance behavior resulting in absence from work. The present study investigates the influence of fear avoidance beliefs on long-term sickness absence. Methods Workers of the general working population with musculoskeletal pain (low back, neck/shoulder, and/or arm/hand pain; n = 8319) from the Danish Work Environment Cohort Study were included. Long-term sickness absence data were obtained from the Danish Register for Evaluation and Marginalization (DREAM). Time-to-event analyses (cox regression) controlled for various confounders estimated the association between fear avoidance beliefs (very low, low, moderate [reference category], high, and very high) at baseline and long-term sickness absence (LTSA; ≥6 consecutive weeks) during a 2-year follow-up. Results During the 2-year follow-up, 10.2% of the workers experienced long-term sickness absence. In the fully adjusted model, very high-level fear avoidance increased the risk of LTSA with hazard ratio (HR) of 1.48 (95% CI 1.15-1.90). Similar results were seen analyses stratified for occupational physical activity, i.e., sedentary workers (HR 1.72 (95% CI 1.04-2.83)) and physically active workers (HR 1.48 (95% CI 1.10-2.01)). Conclusion A very high level of fear avoidance is a risk factor for long-term sickness absence among workers with musculoskeletal pain regardless of the level of occupational physical activity. Future interventions should target fear avoidance beliefs through information and campaigns about the benefits of staying active when having musculoskeletal pain.

Is fatigue after work a barrier for leisure-time physical activity? Cross-sectional study among 10,000 adults from the general working population.

In spite of the many health-related benefits of regular physical activity, fatiguing work may be a barrier to performing leisure-time physical activity. This study investigates the association between work-related fatigue and the duration of low- and high-intensity leisure-time physical activity in workers with sedentary and physically demanding jobs. From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners from the general working population ( N=10,427) replied to questions about work-related fatigue (predictor) and duration of low- and high-intensity leisure-time physical activity (outcome). Associations were modelled using general linear models controlling for various confounders. Among workers with physically demanding jobs, higher levels of work-related fatigue were associated with gradually lower levels of leisure-time physical activity - for low, moderate and high levels of work-related fatigue the duration of high-intensity leisure-time physical activity was 133 (95% confidence interval (CI) 127-178), 134 (95% CI 109-160) and 113 (95% CI 86-140) min per week, respectively (trend test p<0.001). The duration of high-intensity leisure-time physical activity was lower among older workers (≥50 years) compared to younger workers (<50 years) (132 ± 126 vs 168 ± 150 min per week) ( p<0.0001). The duration of high-intensity leisure-time physical activity gradually decreases with increased work-related fatigue in workers with physically demanding jobs. Older workers perform less high-intensity physical activity than younger workers. Workplaces should consider initiatives to allow workers with physically demanding jobs and older workers to perform physical exercise during working hours and thereby increase physical capacity to meet the job demands.

Physical activity during work and leisure show contrasting associations with fear-avoidance beliefs: cross-sectional study among more than 10,000 wage earners of the general working population.

The association between different types of physical activity and fear-avoidance beliefs remains unclear. This study investigates the association between work-related and leisure-time physical activity with fear-avoidance beliefs in the general working population. Currently employed wage earners (n=10,427) from the 2010 round of the Danish Work Environment Cohort Study replied to questions about work, lifestyle and health. General linear models controlling for lifestyle, psychosocial work factors, education, pain, medication-use and chronic diseases tested associations of work-related and leisure-time physical activity (explanatory variables) with fear-avoidance beliefs (outcome variable, scale 0-100). The level of fear-avoidance was 41.7 (SD 27.3), 38.0 (SD 26.9) and 54.3 (SD 27.7) among the general working population, a subgroup of pain-free individuals, and a subgroup with back disease, respectively. In the general working population, the level of fear-avoidance among those with low, moderate and high physical activity during leisure were 47 [95% confidence intervals (CI) 45-49], 44 (95% CI 42-46) and 43 (95% CI 41-45), and physical activity at work were 40 (95% CI 39-42), 44 (95% CI 42-46) and 49 (95% CI 48-51), respectively. Individuals with back disease and a high level of physical activity at work showed the overall highest level of fear-avoidance whereas pain-free individuals with a low level of physical activity at work showed the overall lowest level of fear-avoidance. Physical activity during work and leisure shows contrasting associations with fear-avoidance beliefs. While high physical activity during leisure is associated with lower levels, high physical activity at work is associated with higher levels of fear-avoidance. The present results may reflect some deeply rooted negative beliefs about pain and work in the population. On the societal level, campaigns may be a possible way forward as these have shown to improve beliefs about musculoskeletal pain and work.

The longitudinal association between multiple job holding and long-term sickness absence among Danish employees: an explorative study using register-based data

PurposeMultiple job holding (MJH) is common in many countries, but little is known about its (health) consequences. Our aim is to explore the longitudinal association between MJH and long-term sickness absence (LTSA) among Danish employees.MethodsWe included employees (N = 8968) who participated in the Danish Work Environment Cohort Study (DWECS), based on a representative sample of the Danish working population. Three dichotomous independent variables were created: MJH in general, combination MJH (i.e. second job as employee) and hybrid MJH (i.e. self-employed in second job). LTSA (≥5 weeks) was measured using the Danish Register for Evaluation of Marginalization during 78 weeks of follow-up. Potential confounders included demographics, health, and work characteristics. Logistic regression analyses were performed to study whether LTSA was associated with MJH in general, combination MJH, and hybrid MJH. Interaction effects for gender, age, total working hours per week (≤37 or >37 h a week), and shift work were tested.ResultsIn total, 11.7% (N = 1048) of the respondents reported having multiple jobs and 7.6% (N = 678) experienced LTSA during follow-up. After adjustment for confounders, no significant association between LTSA and MJH in general (OR = 0.82), combination MJH (OR = 0.81), or hybrid MJH (OR = 0.83) was found. Among employees working more than 37 h per week, combination MJH was associated with a higher likelihood of LTSA (OR = 1.50).ConclusionsWe did not find evidence for an increased likelihood of LTSA among multiple job holders. Future research should study the likelihood of LTSA among subgroups of multiple job holders, e.g. those working long hours.

Overweight and obesity are progressively associated with lower work ability in the general working population: cross-sectional study among 10,000 adults.

Obesity is associated with many diseases and functional limitations. Workplaces are not always designed to accommodate this challenge. This study investigated the association between body mass index (BMI) and work ability in the general working population. Currently employed wage earners (N=10,427) from the 2010 round of the Danish Work Environment Cohort Study (DWECS) replied to questions about work and health. Cumulative logistic regression analyses controlling for age, gender, physical and psychosocial work factors, lifestyle, and chronic diseases modeled the associations between BMI and work ability. BMIs above the normal range were progressively associated with lower work ability in relation to the physical demands of the job. Odds ratios for having lower work ability were 1.11 (95% CI 1.01-1.22), 1.17 (95% CI 1.01-1.34), 1.43 (95% CI 1.09-1.88), 1.69 (95% CI 1.10-2.62) for overweight and obesity classes I, II, and III, respectively. In subgroup analyses, the associations between BMI and work ability were more pronounced among individuals with mainly sedentary work than among those with physically active work. BMI was not associated with work ability in relation to the mental demands of the work. BMIs above the normal range are progressively associated with lower work ability in relation to the physical demands of the job, especially among individuals with mainly sedentary work. Ergonomic research on how to optimally design workstations for workers with obesity are needed.

Does age modify the association between psychosocial factors at work and deterioration of self-rated health?

Objectives Few epidemiological studies have examined whether associations of psychosocial working conditions with risk of poor health differ by age. Based on results from mostly cross-sectional studies, we test whether (i) psychosocial relational factors (social support) are more strongly associated with declining health of older than younger employees and (ii) psychosocial job factors (workpace, influence, possibilities for development) are more strongly associated with declining health of younger than older employees. Methods We extracted two cohorts from the Danish Work Environment Cohort Study (DWECS): the 2000-2005 and 2005-2010 cohorts. The participating 5281 employees with good self-rated health (SRH) at baseline were observed in 6585 5-year time windows. Using log-binomial regression analyses, we analysed whether psychosocial factors at work predicted 5-year deterioration of SRH. Effect modification by age was estimated by calculating relative excess risk due to interaction (RERI). Results High workpace among men, low influence at work as well as low social support from colleagues among women, and low possibilities for development and low social support from supervisors among both genders predicted 5-year decline in SRH. Of the 20 interaction analyses, only 1 was statistically significant and in the opposite direction of what was hypothesized (higher risk for declining SRH among middle-aged men with low possibilities for development compared to the young men with high possibilities for development). Conclusions Psychosocial working conditions predicted decline in SRH in this 5-year follow-up study. The model did not support our hypotheses about modifying effects by age.

Job satisfaction is more than a fruit basket, health checks and free exercise: Cross-sectional study among 10,000 wage earners.

Aim: Workers who are satisfied with their job are the cornerstones of healthy and productive companies. This study investigated factors associated with job satisfaction in the general working population. Methods: From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners (N=10,427) replied to questions about work, lifestyle and health. Multinomial logistic regression controlled for sex, age, job group, smoking, body mass index, chronic disease and general health assessed the association between work factors and job satisfaction (very satisfied and satisfied, respectively, with unsatisfied as reference). Results: Psychosocial work factors – social support from superiors, social support from colleagues and influence at work – had the strongest association with job satisfaction. For example, for high social support from superiors, the odds ratio (OR) for being very satisfied with the job was 12.35 (95% confidence interval [CI] 8.71–17.51). With sedentary work as reference, the OR for being very satisfied with the job for ‘standing and walking work that is not strenuous’ was 1.57 (95% CI 1.06–2.33), while the opposite was seen for ‘heavy and strenuous work’ with an OR of 0.34 (95% CI 0.18–0.62). Only two out of five types of workplace health-promotion offers (physical exercise and healthy diet) were associated with job satisfaction. For example, for offers of physical exercise the OR for being very satisfied with the job was 1.84 (95% CI 1.33–2.55). Conclusions: While psychosocial work factors and to some extent physical work demands are important for job satisfaction, workplace health-promotion offers appear to play a minor role.

The association of health and voluntary early retirement pension and the modifying effect of quality of supervision: Results from a Danish register-based follow-up study.

Objectives: The aims of this article are to (1) determine whether and to what extent general perceived health and quality of supervision predict voluntary early retirement pension (VERP) and (2) assess whether quality of supervision modifies the association between general perceived health and VERP. Methods: Employees aged 49–64 years who participated in the Danish Work Environment Cohort Study in 2000 were selected. Their questionnaire data about health and work were linked to register data on social transfer payments, among others VERP, from 2001 to 2012 in the Danish Register for Evaluation of Marginalization (N=1167). Cox proportional hazards analyses were performed to identify the prospective association of general perceived health and quality of supervision on VERP. Relative excess risks due to interaction (RERIs) were calculated to assess whether quality of supervision modified the association between health and VERP. Results: Employees with poor health at baseline had an increased risk of VERP during follow-up (hazard ratio [HR]=1.23; 95% confidence interval [CI] 1.02–1.49). Quality of supervision at baseline was not associated to VERP during follow-up (HR=1.04; 95% CI 0.90–1.21). There was no statistically significant interaction of poor health and poor quality of supervision with regard to risk of VERP (RERI=−0.33; 95% CI −1.79 to 1.14). Conclusions: This study did not support the notion that quality of supervision buffers the association between poor health and VERP. Future research is needed to determine whether other aspects of supervision, for example supervisors’ opportunities to effectuate workplace adjustments, may modify the association of poor health and VERP.

Does age modify the association between physical work demands and deterioration of self-rated general health?

Objective Due to the growing proportion of older employees in the work force in several countries, the importance of age in the association between work and health is becoming increasingly relevant. Few studies have investigated whether age modifies the association of physical work demands with health. We hypothesized that the association of demanding body postures with deteriorated self-rated health (SRH) is stronger among older employees than among younger employees. Method We analyzed three 5-year cohorts in the Danish Work Environment Cohort Study comprising 8318 observations from 5204 employees (follow-up participation rate 83%) with good baseline SRH. Physical work demands were assessed as demanding body postures. Age was divided into tertiles; young (18-32 years), middle-aged (33-43 years) and old (44-59 among men and 44-54 years among women). Poor SRH ("fairly good", "poor", and "very poor") was measured with a single item. Log binomial regressions were stratified by gender. Effect modification (ie, interaction) was defined as deviation from additivity and examined by calculating the relative excess risk due to interaction (RERI). The reference group was employees aged 18-32 years with low physical exposure. Results When predicting deterioration of SRH, an interaction between demanding body postures and age was found among men [RERI: 0.75, 95% confidence interval (95% CI) 0.16-1.34, regarding the age group 44-59 years] and among women (RERI: 0.84, 95% CI 0.19-1.34, for the age group 33-43 years; and 1.17, 95% CI 0.42-1.93, for the age group 44-54 years). Conclusion The study findings suggest that demanding body postures have a stronger impact on health among older compared to younger employees.

Joint association of multimorbidity and work ability with risk of long-term sickness absence: a prospective cohort study with register follow-up.

Objectives The aim of this study was to determine the joint association of multimorbidity and work ability with the risk of long-term sickness absence (LTSA) in the general working population. Methods Cox regression analysis censoring for competing events (statutory retirement, early retirement, disability pension, immigration, or death) was performed to estimate the joint association of chronic diseases and work ability in relation to physical and mental demands of the job with the prospective risk for LTSA (defined as ≥6 consecutive weeks during 2-year follow-up) among 10 427 wage earners from the general working population (2010 Danish Work Environment Cohort Study). Control variables were age, gender, psychosocial work environment, smoking, leisure physical activity, body mass index, job group, and previous LTSA. Results Of the 10 427 respondents, 56.8% had experienced ≥1 chronic disease at baseline. The fully adjusted model showed an association between number of chronic diseases and risk of LTSA. This association was stronger among employees with poor work ability (either physical or mental). Compared to employees with no diseases and good physical work ability, the risk estimate for LTSA was 1.95 [95% confidence interval (95% CI) 1.50-2.52] for employees with ≥3 chronic diseases and good physical work ability, whereas it was 3.60 (95% CI 2.50-5.19) for those with ≥3 chronic diseases and poor physical work ability. Overall, the joint association of chronic disease and work ability with LTSA appears to be additive. Conclusions Poor work ability combined with ≥1 chronic diseases is associated with high risk of long-term sickness absence in the general working population. Initiatives to improve or maintain work ability should be highly prioritized to secure sustainable employability among workers with ≥1 chronic diseases.