Occupational physical activity and mortality risk among 756 377 adults: A prospective cohort register-based study with 13 years follow-up

• There is mixed evidence on how occupational physical activity might affect mortality risk in working populations from different countries. • This study uses a large representative sample of administrative registers included in a homogeneous dataset. • Our results partially support prior research showing higher mortality risk for higher occupational physical activity in men. Recent research from Nordic countries observed higher levels of occupational physical activity (OPA) to increase mortality risk. However, research is required to clarify generalizability to other countries as several studies have found no or even an inverse association for certain subgroups. We aimed to investigate the association between OPA and mortality, retrieving administrative data from a Spanish population. In a prospective cohort study, individuals from the Continuous Working Life Sample (CWLS), a representative sample with administrative registers of the workforce in Spain were followed up from baseline (January 1, 2006) to either death date or end of follow-up (September 1, 2019). During 13.6 years from baseline to the end of follow-up, 23,975 (3.2 %) of the participants died. The full adjusted model showed significant associations for men aged 18–36 years in moderate (HR, 1.54; 95 % CI, 1.26–1.88), high (HR, 1.26; 95 % CI 1.01–1.58), and very high OPA (HR, 1.44; 95 % CI, 1.15–1.80). Men aged 37–64 years solely showed a significant HR for moderate OPA (HR, 1.10; 95 % CI, 1.04–1.16), whereas no significant association was found in women. These results warrant preventative measures to address early mortality among young working men in highly demanding physical jobs.