24-hour sleep/wake patterns in healthy elderly persons.

The purpose of this study was to examine the 24-hour sleep/wake patterns of healthy elderly persons. Data was obtained from 14 elderly subjects who wore a wrist actigraph for 48 hours and completed an activity diary during the monitoring period. Although subjects spent slightly more than 7.5 hours in bed at night, they were asleep for just over 6 hours. Subjects did not have trouble falling asleep, but once asleep, had trouble remaining asleep. All subjects took one or more naps during the recording period, but daytime naps composed only a small fraction of their total sleep time. Total duration of daytime sleep averaged 59.8 minutes.