Sleep and daytime sleepiness problems among patients with chronic noncancerous pain receiving long-term opioid therapy: A cross-sectional study

Objective: Sleep problems are common among patients with chronic pain (CP). Information on sleep problems and associated covariates in opioid-treated patients with CP is limited. The aim of this study was to assess the prevalence, characteristics, and risk factors of sleep and day-time sleepiness problems in this specific population. Design: Cross-sectional. Setting: Primary care outpatient clinics. Participants: Eight hundred and seventy six patients with CP treated with long-term opioids. Main outcome measures: Prestudy selected questionnaires: six questions from the Medical Outcomes Study Sleep Scale, Pain Inventory Survey, Pain Patient Profile, Substance Dependence Severity Scale, and medication log. Results: Insomnia-type sleep problems and combined sleep and sleepiness problems were reported by 87 percent and 49 percent of the sample, respectively. Logistic regression analysis showed that depression (adjusted OR, aOR 2.8, 95% CI 2.1-3.7) and pain severity (aOR 1.4, 95% CI 1.1-1.7) were the strongest independent predictors of sleep problems; only depression severity predicted daytime sleepiness (aOR 1.9, 95% CI 1.6-2.2) or combined sleep/sleepiness problems (aOR 2.2, 95% CI 1.8-2.5). Opioid dose was associated with a slight tendency toward unrefreshing sleep (aOR 1.2, 95% CI 1.0-1.4) and worse sleep maintenance (aOR 1.2, 95% CI 1.0-1.4), while use of long-acting opioids was associated with a trend toward increased napping (aOR 1.3, 95% CI 1.0-1.8). Conclusions: Sleep and daytime sleepiness problems are common among opioid-treated primary care patients with CP and seem to be related mainly to depression and pain severity. Physicians caring for opioid-treated patients with CP may want to asess them for sleep disorders as a part of routine CP care.