Mortality from cardiovascular disease in a cohort of Swedish seafarers

Abstract

Purpose: The aim of this study was to investigate whether Swedish seafarers have increased mortality from cardiovascular disease compared with the general population. Methods: Register-based longitudinal cohort study of 85,169 Swedish seafarers where all subjects with a minimum of 30 days service registered in the Seafarers’ Register 1985–2013 were included. Mortality from coronary heart disease, cerebrovascular disease and total mortality for comparison were analysed by calculating standardised mortality ratios (SMRs), with 95% confidence intervals (CIs). Mortality was further analysed by gender, duty on board, type of vessel, and over time. Results: There was no increase in either mortality from cardiovascular disease or total mortality for seafarers, who had worked solely on passenger ferries. Mortality from coronary heart disease and cerebrovascular disease was increased for male seafarers < 46 years old who had worked on different types of vessels, SMR 1.48 (95% CI 1.06–2.01) and SMR 1.93 (95% CI 1.16–3.02), respectively. Analysing the seafarers by duty showed significantly increased SMRs from coronary heart disease in males aged < 46 of the categories “deck crew” and “engine officer/crew (ever)”. The total mortality for seafarers who had worked on different types of vessels was increased; males SMR 1.05 (95% CI 1.02–1.09) and females SMR 1.17 (95% CI 1.04–1.30), but decreased over time. Conclusions: No increased mortality on passenger ferries but younger male seafarers on different types of vessels had increased mortality from cardiovascular disease. Reduction of hazardous occupational exposures onboard is important, such as shift work, stress and noise.