Prevalence of sleep disturbances in patients with chronic non-cancer pain: A systematic review and meta-analysis.

In individuals with chronic pain, sleep disturbances have been suggested to increase suffering, perception of pain, and to negatively affect long-term prognosis. This systematic review and meta-analysis aims to determine the pooled prevalence of sleep disturbances in chronic non-cancer pain patients with no other sleep disorders, using the patient-rated questionnaires Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI). Multiple databases were searched for studies reporting the prevalence of sleep disturbances in chronic pain patients. The meta-analysis was conducted to examine the pooled prevalence of PSQI and ISI data using the inverse-variance random-effects model and to examine mean differences in PSQI scores. The systematic search resulted in 25,486 articles and 20 were included for analysis. In 12 studies using PSQI, the pooled prevalence of sleep disturbance was 75.3% among 3597 chronic pain patients. In eight studies using ISI, the pooled prevalence was 72.9% among 2578 chronic pain patients. The meta-analysis showed a significant mean difference of 2.75 (p < 0.001) in the global PSQI score between the chronic pain group versus the non-chronic pain group. The relatively high prevalence of sleep disturbances in chronic pain patients emphasizes the importance of further characterizing the relationship between sleep and chronic pain.