8285566 Occupational exposures and risk of injuries, disease and death among offshore petroleum workers and their offspring: a study protocol

<h3>Objective</h3> The lack of comprehensive personnel lists and work histories after the year 2000 has hampered epidemiological studies of recent exposure and risk of injuries, disease, and death in Norwegian offshore petroleum industry workers. The overarching purpose of the study is to assess hydrocarbon exposure, night shift work, and prescription drug use in relation to risk of injuries, cancer, cardiovascular-, neurological-, and respiratory diseases, psychological conditions, and death, in a combined cohort of Norwegian offshore petroleum workers and their offspring covering 1965–2023. <h3>Material and Methods</h3> The Norwegian Offshore Petroleum Workers cohort (n=27,917, work histories 1965–1998), and the Heliport cohort (n=83,202, work histories 1980–2023), will be merged into a combined cohort (n=100,332) with work histories spanning 1965–2023. The combined cohort will be linked to the Medical Birth Registry of Norway for identification of the offshore worker’s offspring (n≈186,000). Exposures will be assessed through work histories linked to industry-specific job-exposure matrices, and two survey-questionnaires (from 1998 and 2023). The combined cohort will be linked to national registries for follow-up of injuries, disease, and death 1999–2023. <h3>Analysis and results</h3> Excess mortality and incidence will be assessed by calculation of standardized mortality and incidence ratios. Cause-specific analyses will be conducted by Cox regression or cumulative incidence from multistate models. Inverse probability of treatment weights will be used to estimate adjusted (weighted) cumulative incidence curves with death as a competing event. <h3>Conclusion</h3> Merging the NOPW and Heliport cohorts creates a uniquely comprehensive dataset with six decades of offshore work histories, detailed exposure and covariate data. High-quality outcome data from national registers enable a broad range of investigations including injuries, cancer and other non-communicable diseases, death and drug use. This will advance research on exposure-related risks in offshore workers and their offspring and facilitate disease prevention in the petroleum industry.