Seafarer fatigue: a systematic review and narrative synthesis of concepts, risk factors, prediction methods, and risk management strategies

Seafarer fatigue is a major contributing factor to maritime accidents and has gained widespread attention in the shipping industry. However, existing evidence remains fragmented across different fatigue concepts, measurement approaches, risk factors, prediction models, and management strategies. This systematic review and narrative synthesis aimed to critically synthesize current evidence on seafarer fatigue, with particular attention to its conceptualization, risk factors, subgroup differences, prediction approaches, and fatigue risk management strategies. A systematic search was conducted in Web of Science, Scopus, PubMed, CNKI, and Wanfang from January 2000 to April 2026. Additional studies were identified through citation searching. After screening and eligibility assessment, 56 studies were included. Owing to substantial heterogeneity in study designs, populations, fatigue definitions, measurement tools, and outcomes, no meta-analysis was conducted; instead, findings were synthesized narratively. The review indicates that seafarer fatigue is a multidimensional phenomenon shaped by sleep and recovery conditions, work organization, shipboard environmental stressors, individual and psychosocial factors, and organizational or regulatory contexts. This review highlights the need for clearer fatigue concepts, stronger subgroup-specific evidence, externally validated prediction models, and integrated fatigue risk management systems tailored to diverse maritime working conditions.