Restorative sleep predicts the resolution of chronic widespread pain: results from the EPIFUND study.

OBJECTIVES: Poor sleep is associated with chronic widespread pain (CWP). Conversely, good-quality sleep may play a role in the resolution of pain symptoms. Sleep is a multidimensional construct, comprising a number of diverse components. The aims of the current study were to examine the hypotheses that: (i) good sleep quality would predict the resolution of CWP, (ii) restorative sleep would predict the resolution of CWP and (iii) that these relationships would be independent of confounding psychological factors. METHODS: Subjects in a population-based prospective study completed a pain questionnaire at baseline from which subjects with CWP were identified. Baseline sleep was measured using the Estimation of Sleep Problems Scale which measures sleep onset, maintenance, early wakening and restorative sleep. The questionnaire also contained scales examining psychosocial status. Subjects were followed up 15 months later and pain status was assessed. RESULTS: A total of 1061 subjects reported CWP at baseline of whom 679 (75% of eligible subjects) responded at follow-up. Of those, a total of 300 (44%) no longer satisfied criteria for CWP. Univariate analysis revealed that three of the four sleep components were associated with the resolution of CWP: rapid sleep onset, odds ratio (OR) = 1.7, 95% CI 1.2, 2.5; absence of early wakening, OR = 1.6, 95% CI 1.1, 2.4; and restorative sleep, OR = 2.7, 95% CI 1.5, 4.8. After adjusting for the effect of psychosocial factors, which may have confounded the relationship, only restorative sleep (OR = 2.0, 95% CI 1.02, 3.8) was associated. CONCLUSIONS: Self-reported restorative sleep was independently associated with the resolution of CWP and return to musculoskeletal health.