Are there differences between officers and ratings on merchant vessels concerning effort–reward imbalance: a cross-sectional maritime field study

PURPOSE: Today, measures to economise in the operation of ships can cause either an effort–reward imbalance or health impairments. The goal of this study was to assess the risk of effort–reward imbalance including overcommitment among officers and ratings on merchant vessels during their assignments and to evaluate lifestyle factors of seafarers as well as the health-promoting conditions on board. METHODS: A study sample of 308 male seafarers was examined during a total of 20 sea voyages on German container ships (participation rate 91.9%). RESULTS: Only 11 seafarers were identified as having an increased health risk of an effort–reward imbalance (ER ratio > 1). Officers tended to have a higher risk of an elevated ratio than ratings (4.4% vs. 3.1%) and also showed a significantly higher risk of an ER ratio above the median (58.8% vs. 41.8%; p = 0.022). Compared to land-based populations, the average overcommitment score of seafarers was high (17.9)—particularly among officers (20.3 vs. 16.5; p = 0.031). This corresponded to an elevated risk of overcommitment among officers compared to ratings (OR 2.14; 95% CI 1.78–2.37). This elevated risk remained significant after adjustment for age (OR 2.11; 95% CI 1.76–2.35) and job-related stressors. CONCLUSION: Although an elevated risk of effort–reward imbalance was only observed in few seafarers, this study revealed a high prevalence of overcommitment particularly among officers. In the course of time, overcommitment can lead to mental exhaustion. Therefore, shipboard health-promoting conditions need to be optimised.