Sleep characteristics and self-reported sleep quality in the oldest-old: Results from a prospective longitudinal cohort study.

Little is known about the correlation between subjective perception and objective measures of sleep quality in particular in the oldest-old. The aim of this study was to perform longitudinal home sleep monitoring in this age group, and to correlate results with self-reported sleep quality. This is a prospective longitudinal home sleep-monitoring study in 12 oldest-old persons (age 83-100 years, mean 93 years, 10 females) without serious sleep disorders over 1 month using a contactless piezoelectric bed sensor (EMFIT QS). Participants provided daily information about perceived sleep. Duration in bed: 264-639 min (M = 476 min, SD = 94 min); sleep duration: 239-561 min (M = 418 min, SD = 91 min); sleep efficiency: 83.9%-90.7% (M = 87.4%, SD = 5.0%); rapid eye movement sleep: 21.1%-29.0% (M = 24.9%, SD = 5.5%); deep sleep: 13.3%-19.6% (M = 16.8%, SD = 4.5%). All but one participant showed a weak (r = 0.2-0.39) or very weak (r = 0-0.19) positive or negative correlation between self-rated sleep quality and the sleep score. In conclusion, longitudinal sleep monitoring in the home of elderly people by a contactless piezoelectric sensor system is feasible and well accepted. Subjective perception of sleep quality does not correlate well with objective measures in our study. Our findings may help to develop new approaches to sleep problems in the oldest-old including home monitoring. Further studies are needed to explore the full potential of this approach.