Cardiovascular mortality among seafarers: a Danish nationwide cohort study

Objectives Cardiovascular disease (CVD) is the leading cause of death globally and the second most frequent cause of death in Denmark. Due to their unique occupational environment, seafarers are exposed to numerous risk factors for CVD including lifestyle and work-related factors. This study aims to investigate CVD mortality among Danish seafarers by comparing them to the economically active reference population. Methods This register-based cohort study included data on all Danish seafarers from 1993 to 2016 and compared them with the economically active Danish population not working as seafarers. The seafarers’ mortality was calculated using piecewise stratified Cox regression adjusting for potential confounders. Mortality was further analysed by diagnosis groups, vessel type and employment duration. Results Among 52 861 seafarers, 4226 deaths were observed, with 866 (20.5%) of these attributed to CVD. Male seafarers had higher all-cause mortality in age groups 18–44 years (HR 1.46, 95% CI 1.33 to 1.62), 45–64 years (HR 1.43, 95% CI 1.37 to 1.50) and 65+ years (HR 1.32, 95% CI 1.26 to 1.39) compared with the reference population. CVD mortality was increased for male seafarers aged 45–64 years (HR 1.27, 95% CI 1.13 to 1.42) and 65+ years (HR 1.34, 95% CI 1.21 to 1.48). The mortality was higher for male seafarers for ischaemic heart diseases, other forms of heart diseases, cerebrovascular diseases and diseases of arteries, arterioles and capillaries. CVD mortality was also observed based on vessel type. Conclusions The study provides evidence of elevated CVD mortality among Danish seafarers. Future research should focus on identifying effective strategies to improve the cardiovascular health of seafarers.