The effects of a scheduled nap during the night shift on sleepiness and cognitive functioning in female hospital nurses

The present study aimed to examine the effectiveness of a scheduled nap and its interaction with individual factors on sleepiness and cognition during an 8-hour night shift. All participants were female and had a mean age of 39.0±9.1 years. Mean experience in shift work was 13.6±8.7 years. Most were married (79.8%), with children living in the household (80.7%); the mean number of children of 1.8±1.2. Fifty-six (51.9 %) of the nurses were overweight, and 18.3% were smokers. Participants were predominantly early chronotypes (76.3%). Lower levels of sleepiness were found at 5:00, 6:00, and 7:00 a.m. on nap versus no-nap nights. Increments in performance between 3:00 and 7:00 a.m. were significantly greater on nap versus no-nap nights for DSST correct responses and LCT capacity. No interactions between the nap and any of the individual factors emerged.