8287625 Mortality among Norwegian offshore petroleum workers in two cohorts: comparisons with the working population and the general population

<h3>Objective</h3> Offshore petroleum workers are exposed to various hazards through their work. We aimed to assess all-cause and cause-specific mortality among Norwegian offshore workers in two separate cohorts, with the working population and the general population as references. <h3>Material and Methods</h3> We examined workers first employed offshore during 1983–1998 in 1) the survey-based Norwegian Offshore Petroleum Workers (NOPW) cohort, comprising 25,142 workers (91% men), and 2) the national register-based Nor-Work cohort, comprising 60,096 workers (93% men). The cohorts were linked to the Cause of Death Registry for follow-up 1999–2020. We calculated calendar period- and age-standardized mortality ratios (SMR, 95% CI) for men with the working population (those who had at least one employment record during 1983–1998) as reference. SMRs for women and for the two cohorts with the general population as reference will also be calculated. <h3>Results</h3> Among men, when compared to the working population, all-cause mortality was reduced in both the NOPW cohort (SMR, 95%CI: 0.91, 0.86–0.98) and the Nor-Work cohort (0.48, 0.47–0.50). In both cohorts, death from diabetes was reduced (NOPW: 0.48, 0.22–0.90; Nor-Work: 0.32, 0.23–0.43). In NOPW, death from Parkinson’s disease (3.07, 1.68–5.15) and all cancers combined (1.12, 1.01–1.23) were elevated, while in Nor-Work, the corresponding estimates were reduced. <h3>Conclusion</h3> Reduced all-cause mortality among offshore workers compared to the working population was found for both cohorts. Comparisons to findings with longer inclusion periods and with the general population as reference may elucidate the impact of selection or information biases, including a healthy worker effect. Findings will contribute to a more thorough understanding of mortality patterns among Norwegian offshore workers.