Working hours, side work, and depressive symptoms in physicians: A nationwide cross-sectional study in Japan

Long working hours in Japan is a social concern. This is also true for the working hours of physicians, who often do side work in addition to working at their main hospital. New physician work regulations to be implemented in Japan require work-hour management, including side work. This study examined the association between physicians' overtime and side work hours and their health outcomes.

We conducted a cross-sectional study using data from a survey of working physicians conducted by the Japan Medical Association from 2021 to 2022. Questionnaires completed by 2906 full-time working physicians aged 24-69, excluding junior resident doctors, were analyzed. Depressive symptoms and the presence of thoughts of death or suicide using the Quick Inventory of Depressive Symptomatology - Japanese version was used to assess health outcomes. Logistic regression analysis was performed using overtime at the main place of employment and side work hours as exposure factors.

Both depressive symptoms and thoughts of death or suicide increased in the group with longer overtime hours at the main place of work. A similar tendency was observed for side work but adjusting for overtime hours eliminated the association. In other words, total working hours had an impact on health, regardless of whether overtime work at the main place of employment or side work.

Despite the existence of multiple hurdles to managing working hours, including side work, the working environment for physicians needs to be improved to protect their health and quality of medical care.