Title
Comparison Of Polysomnographic And Self-Report Measures Of Sleep Parameters In Older Individuals
Abstract
Older individuals are more vulnerable to sleep disorders and because of the physical and psychosocial consequences of their insomnia, our ongoing research has focused on evaluating aspects of sleep in the older population,,. The present study was designed to evaluate the nature and implications of similarities and differences between polysomnography (PSG) and self-report measurement. The following questions were addressed: (1) How do scores on various sleep parameters compare when measured by self-report versus PSG? (2) How does the individual's subjective perception of sleep quality relate to selected sleep parameters, as measured by self-report and PSG? (3) How does the sleep experience at home compare with sleep in a sleep laboratory?
The sample consisted of nine older individuals, six women and three men (mean age = 68). All 9 subjects underwent 2 consecutive nights of sleep laboratory evaluation after completing a brief analogue treatment intervention. Participants were recruited from community seniors' groups and met the minimal diagnostic criteria for psychophysiological insomnia set by the International Classification of Sleep Disorders. They kept a daily log of their sleep experiences (Daily Sleep Diary) for a two week pre-intervention baseline period, during a two week analogue treatment period, and for two weeks post intervention. Immediately following the treatment period, subjects underwent two consecutive nights of sleep laboratory evaluation. On both nights they also completed the Daily Sleep Diary.
The following five sleep parameters were explored: sleep onset latency (SOL), duration (WASO) and frequency of nocturnal awakenings (FNA), hours slept during the night, and sleep efficiency. Results were as follows:
1)Comparison of recorded (PSG) and reported (Sleep Diary) sleep parameter scores indicate more frequent recorded than reported nocturnal arousals, and shorter reported than recorded sleep onset latency.
2)Correlation coefficients between equivalent Sleep Diary and PSG scores collected on the same night were not significant.
3)Sleep quality was associated with different variables depending on the modality of assessment. Better sleep quality was most closely, although not significantly, related to reported time slept and sleep efficiency. In contrast, for PSG, sleep quality was most closely related to fewer nocturnal arousals and to less time spent awake during the night.
4)Subjects' sleep diary evaluations of their sleep in the sleep lab are reasonably similar to their Sleep Diary evaluations of their sleep at home.
5)PSG monitoring identified a high rate of undiagnosed medically based sleep disorders: nocturnal myoclonus in four subjects and obstructive sleep apnea in one.
The high incidence of physiologically based sleep disruption, together with the discrepancies in recorded and reported sleep parameters, suggest that for older individuals with insomnia conscious awareness of nocturnal events may not be necessary to the subjective experience of impaired sleep. Polysomnographic and self-report measures seem to reflect complementary aspects of the sleep experience. Thus, our results emphasize the importance of including objective physiological assessment techniques in the evaluation of disorders in initiating and maintaining sleep in older individuals.
Author
Eva Libman, Robert Levy, Laura Creti and Catherine Fichten
Source
Proceedings: 8th Annual Meeting of the Association of Professional Sleep Societies, 1994, p. 226. Reprinted in Sleep Research, 23, p. 132.