Discussion
Nurses' sleep duration between shifts was adversely affected by work schedules and was particularly short between 2 consecutive night shifts. The mean sleep duration for ICU nurses between 2 day shifts was 6.79 hours. The mean sleep duration between 2 night shifts was much less (5.68 hours). This finding is of concern because of the impact of reduced sleep duration on cognitive function, especially when superimposed on the circadian dysfunction inherent in night-shift work. Furthermore, sleep duration between nonworkdays was significantly greater and close to 9 hours. This finding strongly suggests that nurses are sleep deprived during work periods and are catching up on their sleep loss during nonwork periods.