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.