Sleep quality in nurses: a randomized clinical trial of day and night shift workers.

The study investigated the number of days off nurses working night shifts need to recover their sleep quality to the level of daytime workers during their days off. This study included 30 day-shift nurses and 32 night-shift nurses. It was conducted as a randomized clinical trial in the medical and surgical wards of a medical center in northern Taiwan in May and June 2010 using sleep diaries and sleep parameters collected by actigraphy on different workdays and days off. On workdays, the night-shift group had significantly less total sleep time (TST) on Day 5 and significantly lower sleep efficiency (SE) on Day 3 than the day-shift group. TSTs of the two groups on days off were higher than those on workdays. On the 4th consecutive day off, higher TST, a decrease in WASO, and an increase in SE suggests that the night-shift group had recovered their sleep quality to the level of the day-shift group on their days off. The SE of the night-shift group exceeded that of the day-shift group after the 4th consecutive day off, though the difference was not statistically significant in the present study. Based on these data, it is recommended that night-shift workers arrange a period of at least 4 days off after 5 consecutive night shifts and at least 5 days off if the staff who have previously worked night shifts are being assigned a set of different shifts.