Background: Global demographics are changing as societies all over the world are aging. This puts focus on maintaining functional ability and independence into older age. Individuals from lower social classes are at greater risk of developing limitations in physical function later in life. In this study, we investigated the mediating role of working conditions in the association between occupation-based social class and physical function measured as self-reported mobility limitations and objectively measured physical impairment in older age.

Methods: Two Swedish surveys, linked at the individual level, were used (n = 676-814 depending on the outcome). Follow-up time was 20-24 years. Multiple logistic regression analyses were performed with adjustments for age, sex, level of education, mobility, and health problems at baseline. This was followed by analyses of the size of the mediating effect of working conditions.

Results: Working conditions seem to mediate 35-74% of the association between social class and physical impairment in older age. The pattern of mediation was primarily driven by passive jobs, i.e., low psychological demands and low control, among blue-collar workers. Working conditions did not mediate the association between social class and self-reported mobility limitations in older age.

Conclusions: The results of this study indicate that working conditions are important in combating the social gradient in healthy aging, contributing to the evidence regarding the magnitude of impact exerted by both the physical and psychosocial work environment separately and in conjunction.