Gender differences in insomnia and the role of paid work and family responsibilities

A higher prevalence of insomnia in females has been consistently demonstrated across countries and cultures. The aim of this study was to clarify whether gender differences in insomnia could be explained by gender differences in paid work and family responsibilities.

Participants were employees at two local governments in Hokkaido, Japan, who underwent annual health checkups from April 2003 to March 2004. All data were obtained via self-administered questionnaires. Insomnia was evaluated by the Athens Insomnia Scale. For work and family characteristics, occupation, working hours, days off, shift work, visual display terminal (VDT) work, occupational stress, marital status, hours spent on household tasks, childcare, and caregiving were chosen. Data from 7,451 participants (5,951 men and 1,500 women) were analyzed. Logistic regression analysis examined how much paid work and family responsibilities explained gender differences in insomnia.

The prevalence of insomnia in female subjects (31.0%) was significantly larger than in males (23.2%), but the gender difference disappeared after adjustment for paid work and family responsibilities. The results of stratified analyses revealed that significant gender differences were found only among workers with comparatively favorable work and family conditions, such as non-shift work, less than 6 h/day of VDT work, exposure to low levels of occupational stress, household tasks for less than 1 h/day, and not living with persons who needed care and support.

These results suggest that gender differences in insomnia are explained, in the main, by gender differences in work and family characteristics.