Background

Previous studies have found associations between various health factors and behaviors and mental disorders. However, knowledge of such associations with disability pension (DP) due to mental diagnoses is scarce. Moreover, the influence of familial factors (genetics and family background) on the associations are mainly unknown. The aim of the study was to investigate associations between health factors and behaviors and future DP due to mental diagnoses in a twin cohort, accounting for familial confounding.

Methods

A prospective cohort study of Swedish twins (N=28 613), including survey data and national register data on DP and other background factors was conducted. Cox proportional hazards regression models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI) for the whole twin cohort, and for discordant twin pairs.

Results

During follow-up 1998–2008 (median 10 years), 2.2% of the cohort was granted a DP with a mental diagnosis. In the fully adjusted analyses of the whole cohort, the associations of poor or moderate self-rated health (SRH), under- or overweight, former or current tobacco use, or being an abstainer from alcohol were significantly associated with risk of DP due to mental diagnoses. Analyses of discordant twin pairs confirmed all these associations, except for current tobacco use, being independent from familial confounding. Exclusion of individuals with current or previous depression or anxiety at baseline did not influence the associations found.

Conclusions

Poor or moderate SRH, under- or overweight, former tobacco use or being an abstainer from alcohol seem to be strong direct predictors of DP due to mental diagnoses, independently of several confounders of this study, including familial factors.

Background. Occupations and psychosocial working conditions have rarely been investigated as predictors of disability pension in population-based samples. This study investigated how occupational groups and psychosocial working conditions are associated with future disability pension due to musculoskeletal diagnoses, accounting for familial factors in the associations.

Methods. A sample of 24 543 same-sex Swedish twin individuals was followed from 1993 to 2008 using nationwide registries. Baseline data on occupations were categorized into eight sector-defined occupational groups. These were further used to reflect psychosocial working conditions by applying the job strain scores of a Job Exposure Matrix. Cox proportional hazard ratios (HR) were estimated.

Results. During the 12-year (average) follow-up, 7% of the sample was granted disability pension due to musculoskeletal diagnoses. Workers in health care and social work; agriculture, forestry and fishing; transportation; production and mining; and the service and military work sectors were two to three times more likely to receive a disability pension than those in the administration and management sector. Each single unit decrease in job demands and each single unit increase in job control and social support significantly predicted disability pension. Individuals with high work strain or an active job had a lower hazard ratio of disability pension, whereas a passive job predicted a significantly higher hazard ratio. Accounting for familial confounding did not alter these results.

Conclusion. Occupational groups and psychosocial working conditions seem to be independent of familial confounding, and hence represent risk factors for disability pension due to musculoskeletal diagnoses. This means that preventive measures in these sector-defined occupational groups and specific psychosocial working conditions might prevent disability pension due to musculoskeletal diagnoses.

Objective: To investigate annual prevalence of disability pension (DP) from 1992 to 2007 and associations with sociodemographic factors in 1992.

Methods: All twins born between 1928 and 1958 were identified from the Swedish Twin Registry and linked to national records on DP. Descriptive statistics and logistic regressions were applied.

Results: The annual prevalence of DP was 10.7% (9.6% to 11.3%). High age (odds ratio [OR] 9.17; 95% confidence interval [CI] 8.43 to 9.98), low education (OR 4.84; 95% CI 4.31 to 5.42), and being unmarried (OR 2.36; 95% CI 2.22 to 2.50) were associated with DP. The associations remained after adjusting for familial factors.

Conclusions: The fact that the associations remained after control for familial factors indicates that factors not shared by family members, such as choices in adulthood, are of relevance for the associations found.

Purpose

The incidence of disability pension (DP), especially due to mental diagnoses, has increased in many countries, but knowledge of socio-demographic risk factors for DP is limited. Further, the influences of genetics and early-life factors (jointly called familial factors) on these associations remain to be studied. The aims were to study incidence of DP (due to all and mental diagnoses) and associations with socio-demographic factors, and also to establish whether associations differ with DP diagnosis and sex, and are influenced by familial factors.

Methods

A prospective cohort study of all twins born in 1928–1958 (n = 52,609) in Sweden was conducted. The twins were followed from 1993 to 2008 regarding DP. Cox proportional hazard models were applied.

Results

The cumulative incidence of DP was 17 %. Of all the DP diagnoses 20 % were mental. Higher age (≥45 years), being a woman or unmarried, and/or living in a semi-urban area were risk factors for DP. Low education, being a blue-collar worker or being self-employed predicted either higher (all diagnoses) or lower (mental diagnoses) risk of DP. Rural areas were associated with DP due to mental diagnoses. The estimates varied for men and women. After adjustment for familial factors the associations of DP with education and marital status were attenuated and no longer significant. Similar results were apparent for DP due to mental diagnoses and socioeconomic status.

Conclusions

Familial factors may select individuals into some of the established risk environments for DP. Studies investigating the causes of DP need to take such confounding into account.

Objectives

The aim of this study was to investigate associations between psychosocial working conditions, occupational groups defined by sector, and disability pension (DP) with mental diagnoses while accounting for familial confounding.

Methods

A prospective population-based cohort study was conducted, including all Swedish twins who, in January 1993, were living and working in Sweden and not on old-age pension or DP (N=42 715). The twins were followed from 1993–2008 regarding DP. Data on DP, exposures, and covariates were obtained from national registries. Cox proportional hazards regression models with hazard ratios (HR) and 95% confidence intervals (95% CI) were constructed for the whole cohort, and for discordant twin pairs.

Results

The associations for the whole cohort between DP with mental diagnoses and (i) job demands (HR 1.23, 95% CI 1.06–1.43), (ii) job control (HR 0.91, 95% CI 0.83–0.99), (iii) healthcare and social work (HR 1.41, 95% CI 1.04–1.92), and (iv) service and military work (HR 2.07, 95% CI 1.37–3.14) remained after accounting for possible confounders, including familial factors, while the associations between DP and (i) social support, (ii) type of jobs, and (iii) some of the occupational groups were attenuated, becoming non-significant. In the discordant twin pair analyses, commercial work was significantly associated with lower risk of DP (HR 0.55, 95% CI 0.32–0.95).

Conclusions

One unit increase in job demands and working in the occupational groups healthcare and social work or service and military work seem to be risk factors of DP with mental diagnoses, independent from various background factors including familial ones. However, one unit increase in job control or working in commercial work seem to be protective factors of such DP, accounting for confounding factors of this study.