The influence of health conditions, lifestyle factors, and stress on seafarers’ self-rated health — a cross-sectional study

BACKGROUND: Self-rated health (SRH) is a validated holistic indicator of health, yet evidence among seafarers is limited. We examined how health conditions and lifestyle factors relate to poor SRH and whether perceived stress modifies these associations in active-duty seafarers. A total of 22,432 international seafarers who were on board were included in the analysis of an electronic survey distributed via 52 shipping and manning companies in February-March 2024. MATERIAL AND METHODS: An 82-item questionnaire assessed SRH, self-reported health conditions, lifestyle factors (physical activity, sleep/feeling rested, smoking, alcohol risk, loneliness, screen time), and perceived stress. Cross-sectional analyses used descriptive statistics and logistic regression. Models were adjusted for age, sex, rank, and time on board; stress was added as an independent predictor. Additive interactions between stress and lifestyle factors were evaluated using relative excess risk due to interaction (RERI). RESULTS: Poor SRH was strongly associated with multimorbidity and selected conditions, particularly depression/anxiety, gastrointestinal issues, and musculoskeletal issues. In fully adjusted lifestyle models, sedentary behavior, not feeling rested, smoking, loneliness, and excess screen time remained associated with poor SRH, while alcohol risk was not. Stress was independently associated with poor SRH and amplified the effects of not feeling rested, loneliness, and excess screen time. Self-rated health captured a combined burden of physical and mental symptoms as well as recovery--related and psychosocial factors relevant to life at sea. The stress-sensitive clustering of poor sleep/rest, loneliness, and high screen time suggests that interventions may be most effective when stress management is integrated with fatigue and social-connection measures. CONCLUSIONS: Health conditions and modifiable lifestyle/psychosocial factors were associated with seafarers' SRH, and perceived stress acted as both an independent predictor and an effect modifier. Targeting sleep, stress, social well-being, and sedentary recovery patterns may improve perceived health and potentially safety on board.