OBJECTIVE ASSESSMENT OF SLEEP AND ALERTNESS IN MEDICAL HOUSE STAFF AND THE IMPACT OF PROTECTED TIME FOR SLEEP

We studied 26 physicians in postgraduate medical training (''house sta ff'') to objectively quantify their sleep, alertness, and psychomotor performance while working on call. This study provided precise data on the extent of sleep deprivation during a typical call night, the work load factors predictive of sleep loss, and the extent to which protect ed time for sleep within the call night can ameliorate sleep loss and consequent daytime sleepiness. We used ambulatory EEG recording equipm ent and a standardized computer-based performance test to monitor slee p and alertness over the course of a 36-hour call day. Comparisons wer e made between interns provided with 4 hours of protected time for sle ep by a covering resident (''night-float'') and interns without such c overage. As anticipated, we found evidence that hospital interns were severely sleep-deprived, to an extent even greater than prior behavior al observations have suggested. Interns in both conditions spent an av erage of less than 5 hours (295.4 minutes) in bed attempting to sleep and obtained an average of 3.67 hours (220.1 minutes) of sleep (range 37.4-358.4 minutes). Provision of the night-float for 4 hours did not significantly change total sleep time (TST) (212.8 minutes covered vs. 224.9 minutes uncovered), bur sleep efficiency was significantly impr oved (86.5% vs. 70.3%; p = 0.001). Covered interns also obtained signi ficantly more slow-wave sleep than the uncovered interns (65.4 minutes vs. 51.1 minutes; p = 0.05). However, measures of alertness and perfo rmance were not significantly different between the two groups and wer e only weakly related to TST. These data suggest that significant chro nic sleep deprivation is relatively unaffected by sleep obtained in th e hospital and that provision of protected time for sleep does not sig nificantly improve TST.