Perception of sleep

Abstract

The aim of the study was to examine subjective sleep perception not only in patients with insomnia but also in other sleep disorders. A total of 159 patients with insomnia, sleep-related movement disorders (SMD), hypersomnia, and parasomnia underwent full cardiorespiratory polysomnography with videometry during two consecutive nights. In addition, patients filled in sleep logs assessing subjective sleep parameters as well as several questionnaires including the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Center for Epidemiologic Studies-Depression scale (CES-D). For the second night, not only subjective sleep efficiency, total sleep time (TST), and sleep latency but also objective TST and efficiency significantly differed across diagnostic groups. Comparison between subjective and objective TST, efficiency and latency revealed insomnia patients to significantly underestimate their sleep efficiency and TST, while overestimating their sleep latency. Subjective and objective sleep efficiency as well as sleep latencies differed significantly in the SMD group. Parasomnia and hypersomnia patients only showed significant differences in sleep latencies. PSQI scores significantly differed across patient groups. The PSQI is useful as a screening instrument for distinguishing between diagnostic categories of sleep disorders. Not only insomnia patients significantly misinterpreted sleep parameters, but patients with SMD, hypersomnia, and parasomnia also displayed significant misinterpretation of at least one sleep parameter.