Biomechanical and psychosocial occupational exposures: joint predictors of post-retirement functional health in the French GAZEL cohort

Challenges of Measuring Self-Reported Exposure to Occupational Biomechanical Risk Factors Amongst People with Low Literacy Engaged in Manual Labour: Findings from a Cross-Cultural Adaptation and Psychometric Investigation in an African Population with Chronic Low Back Pain

PURPOSE

Occupational biomechanical factors are implicated in the aetiology and progression of low back pain (LBP). This study cross-culturally adapted and psychometrically investigated the Occupational Risk Factor Questionnaire (ORFQ) in a low literate Nigerian Igbo population with chronic LBP.

METHODS

Forward and back translation of the original ORFQ by clinical and non-clinical translators was followed by an expert committee review. The adapted ORFQ was pre-tested amongst rural Nigerian adults with chronic LBP using cognitive think-aloud interviewing. Internal consistency (Cronbach's alpha) and test-retest reliability (unweighted and linear weighted k statistic for item-by-item agreement, and intra-class correlation coefficient-ICC) were investigated amongst 50 rural and urban Nigerian dwellers with chronic LBP. Spearman's correlation and regression analyses were conducted with the Igbo-ORFQ, and measures of disability [World Health Organisation Disability Assessment Schedule (WHODAS 2.0), Roland Morris Disability Questionnaire (RMDQ), Back performance scale (BPS)], pain intensity [Eleven-point box scale (BS-11)] and social support [Multidimensional Scale of Perceived Social Support (MSPSS)], to test construct validity with 200 rural Nigerian dwellers with chronic LBP.

RESULTS

Cross-cultural adaptation highlighted difficulty conceptualising and concretising exposure to biomechanical risk factors. Item-by-item agreement, internal consistency (α = 0.84) and intraclass correlation coefficient (ICC = 0.83) were good. Some unexpected direction of associations between the biomechanical components of the Igbo-ORFQ, and disability, pain intensity, and social support prohibits establishment of construct validity.

CONCLUSION

Prospective studies comparing the Igbo-ORFQ to other measures of exposure to occupational biomechanical risk factors are required to establish the construct validity of the Igbo-ORFQ.

Longitudinal profiles of occupational physical activity during late midlife and their association with functional limitations at old age: a multi-cohort study

OBJECTIVE

The aim was to examine longitudinal profiles of occupational physical activity (OPA) from midlife to retirement and to investigate how the different OPA-profiles are associated with mobility limitations (ML) and activities of daily living (ADL-disability) at old age.

METHODS

Harmonized data from two cohort studies from Finland and the United States, that have followed people from midlife until old age were used. Repeated measurements of self-reported OPA were collected during approximately 11- to 12-year period. Persons who had data on OPA from ≥ 2 time points during the period from mid-working life to retirement were included. Latent class growth analysis was used to identify OPA-profiles. Risk ratios (RRs) with 95% confidence intervals for the associations of the OPA-profiles and later life MLs and ADL-disability were estimated.

RESULTS

Three OPA-profiles were identified in both cohorts: high-persistent, moderate-fluctuating, and low-persistent. For majority OPA remained stable: for workers reporting high or low levels of OPA at midlife, the physical demands of work likely persisted, whereas people reporting moderate level OPA had high fluctuation in their exposure level. Members of high-persistent and moderate-fluctuating OPA-profiles had increased risk of subsequent MLs at old age. The RRs for ADL-disability did not differ between the profiles.

CONCLUSIONS

Perceived OPA remains rather stable for workers reporting high or low physical work demands during midlife, yet fluctuating profiles also exist. Workers exposed to high or moderate OPA have higher risk for MLs when they reach old age. Establishing safe and health-promoting levels of OPA during late working life might have positive long-term consequences on healthy ageing.

Combined exposure to heavy physical workload and low job control and the risk of disability pension: A cohort study of employed men and women in Sweden

OBJECTIVE

To investigate the separate and combined effects of overall heavy physical workload (PWL) and low decision authority on all-cause disability pension (DP) or musculoskeletal DP.

METHODS

This study uses a sample of 1,804,242 Swedish workers aged 44-63 at the 2009 baseline. Job Exposure Matrices (JEMs) estimated exposure to PWL and decision authority. Mean JEM values were linked to occupational codes, then split into tertiles and combined. DP cases were taken from register data from 2010 to 2019. Cox regression models estimated sex-specific Hazard Ratios (HR) with 95% confidence intervals (95% CI). The Synergy Index (SI) estimated interaction effects.

RESULTS

Heavy physical workload and low decision authority were associated with an increased risk of DP. Workers with combined exposure to heavy PWL and low decision authority often had greater risks of all-cause DP or musculoskeletal DP than when adding the effects of the single exposures. The results for the SI were above 1 for all-cause DP (men: SI 1.35 95%CI 1.18-1.55, women: SI 1.19 95%CI 1.05-1.35) and musculoskeletal disorder DP (men: SI 1.35 95%CI 1.08-1.69, women: 1.13 95%CI 0.85-1.49). After adjustment, the estimates for SI remained above 1 but were not statistically significant.

CONCLUSION

Heavy physical workload and low decision authority were separately associated with DP. The combination of heavy PWL and low decision authority was often associated with higher risks of DP than would be expected from adding the effects of the single exposures. Increasing decision authority among workers with heavy PWL could help reduce the risk of DP.

Functioning Changes in Varying Ways After Retirement: A Scoping Review

The association between retirement and functioning remains still poorly known. This scoping review examines physical, social, cognitive, and mental functioning after retirement, describes the changes in them, determines the different aspects that affect functioning, and documents the main characteristics of the phenomenon. We systematically scoped the relevant studies on functioning after retirement using CINAHL, MEDLINE, Medic, and PubMed databases. This scoping review included both qualitative and quantitative studies. The studies were analysed with inductive content analysis. After retirement, functioning was found to decline but also improve, and additionally, inequalities in functioning emerged. Functioning after retirement changed in ways which were: declining functioning, improving functioning, and inequalities in functioning. Only a few qualitative studies were found. This scoping review shows that functioning after retirement changes in varying ways. The results show that more qualitative research is needed to help us gain a more profound understanding on, for example, individuals' motives to improve leisure, physical, and social activities after retirement, which are likely to contribute to changes in functioning. Additionally, further longitudinal studies would offer knowledge about the long-term effects of retirement on the different dimensions of functioning.

Interaction between physical demands and job strain on musculoskeletal symptoms and work performance

This study investigated the interaction between physical demands and job strain on musculoskeletal symptoms in upper extremities (MSUE) and work performance. Two years of prospective data were analysed from 713 full-time workers from twelve manufacturing and healthcare facilities in Washington in the United States. Physical exposure was measured by the Strain Index and Threshold Limit Value for hand activity, giving rise to safe, action, and hazardous physical demand groups. Job strain was calculated as the ratio of psychological job demands to job control. Multilevel modelling analysis showed that job strain affected MSUE and limited work performance less in the high physical demand group than the safe group because the protective effect of job control was smaller in these groups. Findings may suggest that high physical demand jobs are structured such that workers have low job control or high physical demand groups experience job strain not adequately captured by psychosocial variables.Practitioner Summary: The effects of job strain and job control on musculoskeletal symptoms in upper extremities and work performance were smaller among workers with higher physical demands. This could imply that high physical demand jobs limit job control or psychosocial variables may not adequately capture job strain among high physical demand groups.

Retirement age does not modify the association of prior working conditions with self-rated health and mortality in retirees: results from a prospective study of retired French workers

OBJECTIVE

It is unclear whether retirement age can modify the association of working conditions with health and mortality in retirees who are no longer exposed to these conditions.

METHODS

The present study investigated this issue in a cohort of 13,378 French workers in whom self-rated health and mortality were measured over 15 years after statutory retirement. The analyses were also performed in homogenous clusters of workers differentiated on the basis of working conditions, social position, birth and retirement years.

RESULTS

Bad working conditions before retirement, which were assessed using a global score combining 25 different occupational exposures, were associated with higher rates of suboptimum self-rated health and mortality in retirees after adjusting for retirement age, social position, demographics and health status before retirement. These rates were also substantially higher in the cluster of workers characterized by bad working conditions in comparison to other clusters. In contrast, retirement age was not associated with self-rated health or mortality after adjusting for working conditions, social position, demographics and health status before retirement. Likewise, no association of retirement age with self-rated health or mortality was found in any cluster of workers and no interactions were observed with any of these clusters.

CONCLUSION

These results suggest that bad working conditions before retirement have long-term detrimental effects on health and mortality in retirees and that retirement age does not modulate these effects. Improving work environment rather than modifying retirement age should be prioritized to promote health and reduce mortality not only in workers but also in retirees.

Cumulative Risks from Stressor Exposures and Personal Risk Factors in the Workplace: Examples from a Scoping Review

Protecting worker and public health involves an understanding of multiple determinants, including exposures to biological, chemical, or physical agents or stressors in combination with other determinants including type of employment, health status, and individual behaviors. This has been illustrated during the COVID-19 pandemic by increased exposure and health risks for essential workers and those with pre-existing conditions, and mask-wearing behavior. Health risk assessment practices for environmental and occupational health typically do not incorporate multiple stressors in combination with personal risk factors. While conceptual developments in cumulative risk assessment to inform a more holistic approach to these real-life conditions have progressed, gaps remain, and practical methods and applications are rare. This scoping review characterizes existing evidence of combined stressor exposures and personal factors and risk to foster methods for occupational cumulative risk assessment. The review found examples from many workplaces, such as manufacturing, offices, and health care; exposures to chemical, physical, and psychosocial stressors combined with modifiable and unmodifiable determinants of health; and outcomes including respiratory function and disease, cancers, cardio-metabolic diseases, and hearing loss, as well as increased fertility, menstrual dysfunction and worsened mental health. To protect workers, workplace exposures and modifiable and unmodifiable characteristics should be considered in risk assessment and management. Data on combination exposures can improve assessments and risk estimates and inform protective exposure limits and management strategies.

Interaction effects of physical and psychosocial working conditions on the risk of disability pension among nursing professionals and care assistants in Sweden: A prospective study

BACKGROUND

Nursing professionals and care assistants are often subject to a combination of negative physical and psychosocial work environment factors, but most disability pension studies on such occupations have focused on one or the other of these factors. As they often coexist, there are reasons to assume that simultaneously being exposed to both types of exposures will increase the risk of disability more than being exposed to either.

OBJECTIVES

The study examined combinations of physical and psychosocial work conditions as predictors of future disability pension among nursing professionals and care assistants in Sweden.

PARTICIPANTS

The study was based on a random and representative sample of 79,004 participants in any of the Swedish Work Environment Surveys from 1993 to 2013. A total of 2576 nursing professionals, 10,175 care assistants, and 66,253 workers in other occupations were included.

METHODS

Information on background factors and disability pension was obtained from population registers. Cox proportional hazard regressions with 95% confidence intervals (CI) were performed to study if pairs of combinations of physical and psychosocial factors were related to an increased risk of disability pension. Additionally, measures of synergistic effects were estimated. The analyses were stratified on occupation group, with adjustment for selected confounders.

RESULTS

The results indicated increased hazard ratios (HR) for disability pension for most combinations of physical and psychosocial working conditions. The hazard ratios for joint exposure to high demands and heavy physical work were high among both nursing professionals (HR 1.91; CI 1.06-3.44) and care assistants (HR 2.09; CI 1.63-2.69). Also, the combination of high demands and strenuous postures resulted in significantly elevated risks of disability pension among nursing professionals (HR 1.95; CI 1.20-3.16) and care assistants (HR 2.18; CI 1.71-2.77). The HRs for joint exposure to low control and both heavy physical work and strenuous postures were significant among all other occupations (HR 2.30; CI 2.05-2.58 and HR 2.24; CI 2.01-2.51), and among care assistants (HR 1.52; CI 1.26-1.85 and HR 1.61; CI 1.34-1.93), but not significant among nursing professionals. The synergistic effects on disability pension from combined exposures were generally positive among all three occupational groups.

CONCLUSION

Nursing professionals and care assistants exposed to both negative physical and psychosocial conditions had an increased risk of disability pension. A synergistic effect with respect to disability pension was found among care assistants who reported low control and strenuous postures at work.

Psychosocial working conditions, trajectories of disability, and the mediating role of cognitive decline and chronic diseases: A population-based cohort study

BACKGROUND

Unfavorable psychosocial working conditions have been associated with cognitive decline and chronic diseases, both of which may subsequently accelerate functional dependence. This study aimed to investigate the association between job demand-control-support combinations and trajectories of disability in later life and to further explore the role of cognitive decline and the co-occurrence of chronic diseases in mediating this association.

METHODS AND FINDINGS

In this cohort study, 2,937 community dwellers aged 60+ years (mean age 73 ± 10.6; 62.9% female) residing in the Kungsholmen District of Stockholm, Sweden, participated in the baseline survey (2001-2004) and were followed up to 12 years. Lifelong occupational history was obtained through a standardized interview; job demands, job control, and social support at work in the longest-held occupation were graded with a psychosocial job-exposure matrix. Job control, demands, and social support were dichotomized using the median values from the matrix, respectively, to further generate demand-control-support combinations. Disability was measured by summing the number of impaired basic and instrumental activities of daily living. Global cognitive function was assessed by Mini-Mental State Examination. Chronic conditions were ascertained by clinical examinations, medical history, and patient clinical records; the total number of chronic diseases was summed. Data were analyzed using linear mixed-effects models and mediation analysis. Age, sex, education, alcohol consumption, smoking, leisure activity engagement, early-life socioeconomic status, occupational characteristic and physical demands, and baseline cognitive function and number of chronic diseases were adjusted for in the analyses. Compared with active jobs (high control/high demands; n = 1,807), high strain (low control/high demands; n = 328), low strain (high control/low demands; n = 495), and passive jobs (low control/low demands; n = 307) were all associated with a faster rate of disability progression (β = 0.07, 95% CI 0.02-0.13, p = 0.01; β = 0.10, 95% CI 0.06-0.15, p < 0.001; β = 0.11, 95% CI 0.05-0.18, p < 0.001). The association between high strain and disability progression was only shown in people with low social support at work (β = 0.13, 95% CI 0.07-0.19, p < 0.001), but not in those with high social support (β = 0.004, 95% CI -0.09 to 0.10, p = 0.93). Moreover, we estimated that the association between demand-control status and disability trajectories was mediated 38.5% by cognitive decline and 18.4% by accumulation of chronic diseases during the follow-up period. The limitations of this study include unmeasured confounding, self-reported work experience, and the reliance on a psychosocial job-exposure matrix that does not consider variabilities in individuals' perception on working conditions or job characteristics within occupations.

CONCLUSIONS

Our findings suggest that negative psychosocial working conditions during working life may accelerate disability progression in later life. Notably, social support at work may buffer the detrimental effect of high strain on disability progression. Cognitive decline and chronic-disease accumulation, and especially the former, partially mediate the association of psychosocial working conditions with trajectories of disability. Further studies are required to explore more mechanisms that underlie the association between psychosocial working conditions and disability trajectories.

Association between psychosocial factors at work and health outcomes after retirement: a protocol for a systematic review and meta-analysis

INTRODUCTION

The world's population is rapidly ageing, and health among older people is thus an important issue. Several previous studies have reported an association between adverse psychosocial factors at work before retirement and postretirement health. The objective of this systematic review and meta-analysis is to examine the association between psychosocial factors at work and health outcomes after retirement, based on a synthesis of well-designed prospective studies.

METHODS AND ANALYSIS

The participants, exposures, comparisons and outcomes of the studies in this systematic review and meta-analysis are defined as follows: (P) people who have retired from their job, (E) presence of adverse psychosocial factors at work before retirement, (C) absence of adverse psychosocial factors at work before retirement and (O) any physical and mental health outcomes after retirement. Published studies were searched using the following electronic databases: MEDLINE, EMBASE, PsycINFO, PsycARTICLES and Japan Medical Abstracts Society. The included studies will be statistically synthesised in a meta-analysis to estimate pooled coefficients and 95% CIs. The quality of each included study will be assessed using the Risk Of Bias In Non-randomised Studies-of Interventions. For the assessment of meta-bias, publication bias will be assessed by using Egger's test, as well as visually on a funnel plot. Heterogeneity will be assessed using the χ² test with Cochran's Q statistic and I².

ETHICS AND DISSEMINATION

Results and findings will be submitted and published in a scientific peer-reviewed journal and will be disseminated broadly to researchers and policy-makers interested in the translatability of scientific evidence into good practices.

PROSPERO REGISTRATION NUMBER

CRD42018099043.

Work-Related Biomechanical Exposure and Job Strain as Separate and Joint Predictors of Musculoskeletal Diseases: A 28-Year Prospective Follow-up Study

We investigated how work-related biomechanical exposure and job strain in midlife separately and jointly predicted back and degenerative musculoskeletal diseases (MSDs). A total of 6,257 employees participated in the Finnish Longitudinal Study on Aging Municipal Employees (FLAME) in 1981 and were followed up for 28 years. Risk ratios and the relative excessive risk due to interaction and 95% confidence intervals were modeled for separate and joint prediction estimates, respectively. After adjustment for confounders, job strain predicted degenerative MSDs among women after 4 and 11 years of follow-up. After 11 years, both exposures predicted both types of MSDs among men. Joint exposure predicted both types of MSDs after 4 years among women (for back MSDs, risk ratio (RR) = 1.58, 95% confidence interval (CI): 1.15, 2.18; for degenerative MSDs, RR = 1.59, 95% CI: 1.21, 2.07) and men (for back MSDs, RR = 1.50, 95% CI: 1.05, 2.15; for degenerative MSDs, RR = 1.61, 95% CI: 1.16, 2.22) and both types of MSDs after 11 years (for back MSDs, RR = 1.72, 95% CI: 1.21, 2.43; for degenerative MSDs, RR = 1.68, 95% CI: 1.25, 2.46) among men only, but the relative excessive risk due to interaction was not significant throughout. However, after 28 years, the separate and joint exposures did not predict MSDs. Workplace interventions should be focused on reducing job strain along with biomechanical exposure for possible prevention of MSDs in working life and around the time of retirement, but there may be other pathways of onset of MSDs in old age.

Work Characteristics Associated with Physical Functioning in Women

Women make up almost half of the labor force with older women becoming a growing segment of the population. Work characteristics influence physical functioning and women are at particular risk for physical limitations. However, little research has explored the effects of work characteristics on women’s physical functioning. U.S. women between the ages of 50 and 79 were enrolled in the Women’s Health Initiative Observational Study between 1993 and 1998. Women provided job titles and years worked at their three longest-held jobs (n = 79,147). Jobs were linked to characteristics in the Occupational Information Network. Three categories of job characteristics related to substantive complexity, physical demand, and social collaboration emerged. The association between job characteristics and physical limitations in later life, measured using a SF-36 Physical Functioning score <25th percentile, was examined using modified Poisson regression. After controlling for confounding variables, high physical demand was positively associated with physical limitations (RR = 1.09 CI: 1.06–1.12) and substantively complex work was negatively associated (RR = 0.94, CI: 0.91–0.96). Jobs requiring complex problem solving, active learning, and critical thinking were associated with better physical functioning. Employers should explore opportunities to reduce strain from physically demanding jobs and incorporate substantively complex tasks into women’s work to improve long-term health.

Domains of cognitive function in early old age: which ones are predicted by pre-retirement psychosocial work characteristics?

BACKGROUND

Psychosocial work characteristics may predict cognitive functioning after retirement. However, little research has explored specific cognitive domains associated with psychosocial work environments. Our study tested whether exposure to job demands, job control and their combination during working life predicted post-retirement performance on eight cognitive tests.

METHODS

We used data from French GAZEL cohort members who had undergone post-retirement cognitive testing (n=2149). Psychosocial job characteristics were measured on average for 4 years before retirement using Karasek's Job Content Questionnaire (job demands, job control and demand-control combinations). We tested associations between these exposures and post-retirement performance on tests for executive function, visual-motor speed, psychomotor speed, verbal memory, and verbal fluency using ordinary least squares regression.

RESULTS

Low job control during working life was negatively associated with executive function, psychomotor speed, phonemic fluency and semantic fluency after retirement (p's<0.05), even after adjustment for demographics, socioeconomic status, health and social behaviours and vascular risk factors. Both passive (low-demand, low-control) and high-strain (high-demand, low-control) jobs were associated with lower scores on phonemic and semantic fluency when compared to low-strain (low-demand, high-control) jobs.

CONCLUSIONS

Low job control, in combination with both high and low-job demands, is associated with post-retirement deficits in some, but not all, cognitive domains. In addition to work stress, associations between passive work and subsequent cognitive function may implicate lack of cognitive engagement at work as a risk factor for future cognitive difficulties.

Cohort Profile Update: The GAZEL Cohort Study

The original GAZEL cohort was composed of 20 625 employees of the French national gas and electricity companies (15 011 male employees then aged 40 to 50 years and 5614 women between 35 and 50 years old) at its inception in 1989. A Cohort Profile article was published in 2007. By the end of 2013, participants were aged 60-75, and almost all of them retired during follow-up. Accordingly, the main focus of research in the past decade was devoted to the study of the persistent, long-term effects of occupational exposures after retirement; of the transition between professionally active life and retirement; and on determinants of early ageing. Accordingly, in addition to the health, behavioural and social data collected yearly since the beginning of the follow-up, new data were thus collected on cognitive complaints, cognitive and physical functioning, limitations in daily activities, time use and social relationships of retirees. This update presents the main findings of research within the GAZEL Cohort Study during the past 7 years. Any research group, in France or elsewhere, can submit a research proposal to work on the GAZEL cohort. To do this, interested researchers should contact one of the principal investigators of the GAZEL Cohort Study.