Purpose: The aim of this study was to evaluate the prevalence and clinical correlates of impaired sleep quality and excessive daytime sleepiness among patients receiving methadone for opioid use disorder (OUD).
Methods: Patients receiving methadone (n = 164) completed surveys assessing sleep quality (Pittsburgh Sleep Quality Index [PSQI]), daytime sleepiness (Epworth Sleepiness Scale [ESS]), and related comorbidities. We used bivariate and multivariable linear regression models to evaluate correlates of sleep quality and daytime sleepiness.
Results: Ninety percent of patients had poor sleep quality (PSQI >5), and the mean PSQI was high (11.0 ±4). Forty-six percent reported excessive daytime sleepiness (ESS > 10). In multivariable analyses, higher PSQI (worse sleep quality) was significantly associated with pain interference (coefficient = 0.40; 95% CI = 0.18-0.62; β = 0.31), somatization (coefficient = 2.2; 95% CI = 0.75-3.6; β = 0.26), and negatively associated with employment (coefficient = - 2.6; 95% CI = - 4.9 to - 0.19; β = - 0.17). Greater sleepiness was significantly associated with body mass index (coefficient = 0.32; 95% CI = 0.18-0.46; β = 0.33), and there was a non-significant association between sleepiness and current chronic pain (coefficient = 1.6; 95% CI = 0.26-3.5; β = 0.13; p value = 0.09).
Conclusions: Poor sleep quality and excessive daytime sleepiness are common in patients receiving methadone for OUD. Chronic pain, somatization, employment status, and obesity are potentially modifiable risk factors for sleep problems for individuals maintained on methadone. People with OUD receiving methadone should be routinely and promptly evaluated and treated for sleep disorders.
Keywords: Methadone; Opioid; Pain; Sleep quality; Sleepiness; Somatization.