Sleep and ageing: the effect of institutionalization on subjective and objective characteristics of sleep.

To assess the impact of institutionalization on sleep/wake characteristics of elderly people, we compared subjective (study I: n = 160) and objective (study II: n = 30) sleep/wake measures of non-demented institutionalized subjects and age-matched non-institutionalized controls. We also evaluated the prevalence and causes of various sleep disturbances. The three living conditions, i.e. independently living (IL), service home (SH) and nursing home (NH) were respectively assumed to have minimal, moderate and maximal effects upon the timing, the amount and the quality of the sleep/wake behaviour of the persons involved. Study I showed that a higher level of institutionalization was significantly (p < 0.05) associated with phase-advanced sleep/wake patterns, increased amounts of time spent in bed during the 24-hour period and increased usage of prescribed sedative-hypnotic drugs. Poor sleep quality and disturbed sleep onset occurred significantly mostly in the SH group. No differences between groups were demonstrated with respect to the prevalence of disturbed sleep maintenance, parasomnias and difficulty with awakening and their possible causes, except for environmental noise which was exclusively reported by institutionalized subjects. No differences between groups for any of the objective measures were found (study II). Overall, our findings are in line with previous findings on this topic, although the observed high rate of poor sleep quality and sleep disturbances and their associated causes as observed in institutionalized subjects also occurs in an age-matched non-institutionalized population.