Association of occupational physical activity and disability pension in 756,159 Spanish workers: A prospective cohort study with 13 years follow-up

Recent research from Nordic countries identified occupational physical activity (OPA) as a risk factor for disability pension, but further research accounting for exhaustive analyses in novel populations is warranted. Our objective was to assess the association between OPA and disability pension using administrative data. This prospective registry-based cohort study used data from the Spanish Continuous Working Life Sample (CWLS). Participants were followed up from baseline (January 1, 2006) to first event of disability pension, mortality, or end of follow-up (September 1, 2019). The assessment of OPA was based on registers of economic activity and their correspondence with a validated OPA index. To examine the association between OPA and disability pension, adjusted proportional hazard, and Fine-Gray models using mortality as competing risk were conducted. We retrieved data from 756,159 workers (57.7% men) with an average age of 38.5 years (SD 11.9). During 13.6 years from baseline to the end of follow-up (9,463,041 person-years), 18,191 men (4.2%) and 9631 (3.0%) women received a disability pension. In the fully adjusted model, participants exposed to higher levels of OPA showed higher risk for disability pension in an exposure-response fashion. Men and women exposed to very high OPA showed the highest HR for disability pension (2.31 [95% CI, 2.17 to 2.46] and 1.68 [95% CI, 1.56 to 1.81], respectively. These results warrant preventative measures to address early involuntary exit from the labour market in workers exposed to high physical work demands.