Sleep deprivation in junior doctors--house officers in Singapore.

House officers are known to endure marked levels of sleep deprivation in administration of their duties. We aim to establish sleep patterns of local house officers while on the job and the impact it might have on their mood and sleepiness state. We also studied their sleep during their final year of medical school and pre-university for identification of any prior sleep deprivation. Questionnaires were used to assess sleep and mood change. Sleepiness levels on the day after call were assessed using the Stamford Sleepiness Scale. Subjects were found to sleep a median of only 1.0 (+/- 2.0) h per night on call and 6.0 h (+/- 1.0) per non-call night. They suffered median of 5 interruptions (+/- 5) during sleep on one night call. Night call was found to adversely affect mood in 89.5% of the subjects while daytime sleepiness levels following call were found to increase the more the time spent at work after call. Subjects were found to have had 6.5 h (+/- 1.0) of sleep per night during final year of medical school and 8.0 h (+/- 1.0) in final year of pre-university. House officers enter the profession chronically sleep-deprived. The call schedule and general work regime further add to the existent sleep deprivation and may have adverse consequences on patient care and doctor's health. This calls for measures to be instituted for provision of proper sleep and work hours for them.