Assessing the Sleep-wake Pattern in Cancer Patients for Predicting a Short Sleep Onset Latency.

We investigated the sleep parameters and clinical factors related to short sleep onset latency (SL) in cancer patients. We retrospectively reviewed the medical records of 235 cancer patients. Patient Health Questionnaire-9, State and Trait Anxiety Inventory (State subcategory), Insomnia Severity Index (ISI), Cancer-related Dysfunctional Beliefs about Sleep, and Fear of Progression scale scores and sleep related parameters including sleeping pill ingestion time, bedtime, sleep onset time, and wake-up time were collected. We also calculated the duration from sleeping pill ingestion to bedtime, sleep onset time, and wake-up time; duration from wake-up time to bedtime and sleep onset time; and time spent in bed over a 24 hours period. Among patients not taking sleeping pills (n = 145), early wake-up time (adjusted odds ratio [OR]: 0.39, 95% confidence interval [CI] 0.19-0.78), early sleep onset time (OR: 0.50, 95% CI 0.27-0.93), and low ISI score (OR: 0.82, 95% CI 0.71-0.93) were identified as expecting variables for SL ≤ 30 minutes. Longer duration from wake-up time to bedtime (OR: 2.49, 95% CI 1.48-4.18) predicted SL ≤ 30 minutes. Among those taking sleeping pills (n = 90), early sleep onset time (OR: 0.54, 95% CI 0.39-0.76) and short duration from pill ingestion to sleep onset time (OR: 0.05, 95% CI 0.02-0.16) predicted SL ≤ 30 minutes. Cancer patients who fell asleep quickly spent less time in bed during the day. Thus, before cancer patients with insomnia are prescribed sleeping pills, their sleep parameters should be examined to improve their SL.