Table 4.

The summary of evidence related to duty hours and postgraduate residents in Japan.

	Weekly duty hours
	< 60 h	60–80 h	> 80 h
Mental health (our study)
Burnout11	→	→	↑
Depression12,13	→	→	↑
Stress	↓	→	↑
Satisfaction	→	→	→
Education
In-training exam score8	↓	→	→
Self-study time7	↓	→	→
Patient safety	?	?	?

This table shows the factors associated with duty hours of postgraduate residents in Japan. Using 60–80 h weekly (equivalent to 80–120 h of overtime per month) as a reference point, the table shows how these factors change when working less than 60 h weekly or more than 80 h weekly. The references corresponding to each item are presented in the table.