Interaction Effects of Social Isolation and Peripheral Work Position on Risk of Disability Pension: A Prospective Study of Swedish Women and Men

PURPOSE The study examines various combinations of levels of social isolation in private life and peripheral work position as predictors of disability pension (DP). A second aim was to test the potential interaction effects (above additivity) of social isolation and peripheral work position on the future risk of DP, and to provide results for men and women by age. METHOD The study was based on a sample of 45567 women and men from the Swedish population who had been interviewed between 1992 and 2007. Further information on DP and diagnoses was obtained from the Swedish Social Insurance Agency's database (1993-2011). The studied predictors were related to DP using Cox's proportional hazard regression. The analyses were stratified on sex and age (20-39 years, 40-64 years), with control for selected confounders. RESULTS Increased risks of DP were found for most combinations of social isolation and peripheral work position in all strata. The hazard ratios (HRs) for joint exposure to high degree of social isolation and a peripheral work position were particularly strong among men aged 20-39 (HR 5.70; CI 95% 3.74-8.69) and women aged 20-39 (HR 4.07; CI 2.99-5.56). An interaction effect from combined exposure was found for women in both age groups as well as a tendency in the same direction among young men. However, after confounder control the effects did not reach significance. CONCLUSIONS Individuals who were socially isolated and in a peripheral work position had an increased risk of future DP. The fact that an interaction effect was found among women indicates that a combination of social isolation and peripheral work position may reinforce adverse health effects. There was no evidence that a peripheral work position can be compensated by a high degree of social intergration in private life.