Association between unemployment and insomnia-related symptoms based on the Comprehensive Survey of Living Conditions: a large cross-sectional Japanese population survey

This study examined whether employment category was associated with insomnia-related symptoms (IRS). We analyzed the 2010 Comprehensive Survey of Living Conditions in Japan. The anonymous data of 43,865 people ranging from 20–59 yr of age were analyzed. We defined six employment categories: regularly employed, non-regularly employed, self-employed, others, unemployed and not in the labor force. Sex-specific odds ratios (ORs) and 95% confidence intervals (CIs) of IRS were calculated using multivariable logistic regression analysis, adjusted for confounding factors. We further conducted stratified analyses by mental illness, smoking status, and age. For men, the multivariable ORs (95% CI) of IRS for the unemployed and those who were not in the labor force were 2.5 (1.8–3.4) and 2.1 (1.2–3.7). For women, the multivariable ORs (95% CI) for the unemployed was 1.9 (1.5–2.5). After being stratified by mental illness, we found that the associations were not significant in persons with mental illness, and were more evident in persons without mental illness. Smoking and age did not modify the associations. In conclusion, we found a significantly higher OR of IRS for the unemployed, and men who were not in the labor force. These associations were particularly more evident for individuals without mental illness.