Influence of combined exposure to perceived risk at work and unstable employment on self-rated health: a comparison of two cross-sectional surveys in Europe and Korea

Objectives The purpose of this study was to investigate the combined effect of exposure to perceived risk at work and unstable employment on self-rated health in both Korea and the European Union. Design Cross-sectional study. Setting We conducted the analyses using employees data from the third Korean Working Conditions Survey (KWCS) conducted in 2011 and the fifth European Working Conditions Survey (EWCS) conducted in 2010. Participants Employees of the third KWCS and the fifth EWCS from 35 European countries were the participants of the study. Primary outcome measures Employment status was divided into two categories: stable and unstable employment. Perceived risk regarding safety and health at work were assessed. Primary health outcomes were poor or moderate self-rated health. Exposures and health status were assessed via a questionnaire. Results Among Korean employees, the OR of poor self-rated health was 2.00 (95% CI: 1.80 to 2.22) for those with perceived risk at work, 1.18 (95% CI: 1.09 to 1.28) for those with unstable employment and 3.22 (95% CI: 2.72 to 3.81) for those with both perceived risk at work and unstable employment. Relative excess risk due to interaction (RERI) was 1.03 (95% CI: 0.48 to 1.58). Among European employees, the OR for poor self-rated health was 3.20 (95% CI: 2.93 to 3.49) for those with perceived risk at work, 1.04 (95% CI: 0.97 to 1.13) for those with unstable employment and 3.41 (95% CI: 2.93 to 3.98) for those with both perceived risk at work and unstable employment. The RERI was 0.18 (95% CI: −0.36 to 0.71). Conclusions Among Korean employees, a supra-additive interaction between perceived risk at work and unstable employment on poor self-rated health was observed. Conversely, a supra-additive interaction was not observed among European employees.