The subjective–objective mismatch in sleep perception among those with insomnia and sleep apnea

Abstract

SUMMARYThe diagnosis and management of insomnia relies primarily on clinical history. However, patient self-report of sleep-wake times may not agree with objective measurements. We hypothesized that those with shallow or fragmented sleep would under-report sleep quantity, and that this might account for some of the mismatch. We compared objective and subjective sleep-wake times for 277 patients who underwent diagnostic polysomnography. The group included those with insomnia symptoms (n = 92), obstructive sleep apnea (n = 66) or both (n = 119). Mismatch of wake duration was context dependent: all three groups overestimated sleep latency but underestimated wakefulness after sleep onset. The insomnia group underestimated total sleep time by a median of 81 min. However, contrary to our hypothesis, measures of fragmentation (N1, arousal index, sleep efficiency, etc.) did not correlate with the subjective sleep duration estimates. To unmask a potential relationship between sleep architecture and subjective duration, we tested three hypotheses: N1 is perceived as wake; sleep bouts under 10 min are perceived as wake; or N1 and N2 are perceived in a weighted fashion. None of these hypotheses exposed a match between subjective and objective sleep duration. We show only modest performance of a Naïve Bayes Classifier algorithm for predicting mismatch using clinical and polysomnographic variables. Subjectiveobjective mismatch is common in patients reporting insomnia symptoms. We conclude that mismatch was not attributable to commonly measured polysomnographic measures of fragmentation. Further insight is needed into the complex relationships between subjective perception of sleep and conventional, objective measurements.

Sleep Fragmentation Does Not Explain Misperception of Latency or Total Sleep Time

“…22 Second, reporting SDSL in units of minutes avoids the potentially divergent results when standard SL misperception metrics are reported in absolute versus relative terms. 7 Third, it facilitates "correction" of the objective TST, what we termed the LA-TST, and thus avoids double-penalizing TST estimations in individuals who also exhibited SL misperception. Our results do not support the hypothesis that light or fragmented sleep drives misperception of sleep onset or of total sleep.…”

“…These issues are important because there is no gold standard for defining objective SL, and different definitions will yield different results and could impact interpretation. 7 For example, Figure 1A illustrates the range of results obtained if we define objective SL by either the first epoch of sleep versus the latency to persistent sleep (LPS; 10 epochs). We reasoned that the fundamental goal of describing SL misperception is to capture the amount (and type) of sleep that is misperceived during the period of subjective sleep latency, which is not accurately captured by the routine method of subtracting subjective onset and objective onset (regardless of how objective onset is defined).…”

“…6,7 The difficulty in linking sleep metrics to misperception could be due to insensitivity of the metrics for capturing the relevant physiology and/or the manner in which misperception is quantified. For example, survival analysis and similar approaches focusing on sleep stage transition dynamics have been shown to capture fragmentation related to OSA more effectively than standard metrics.…”

“…These populations exhibit a range of misperception and insomnia symptoms, as reported previously. 6,7 Each patient completed a post-sleep survey after overnight testing in our clinical laboratory, in which they indicated their subjective recollection of sleep latency and total sleep time. Responses in units of hours and minutes were compared with objective sleep stage scoring performed by experienced technicians according to American Academy of Sleep Medicine guidelines.…”

“…4 Some patients with obstructive sleep apnea (OSA) may also exhibit misperception, though perhaps not to the same extent as those with insomnia symptoms. [5][6][7] Several hypotheses have arisen regarding the basis for misperception, although a unified explanation remains elusive. For example, misperception has been linked with anxiety and mood, 3,8 personality traits, and sleep physiology measures such as electroencephalogram patterns of alpha-delta sleep or cyclic alternating pattern and high frequency electroencephalography (EEG) content.…”