Objective: About two thirds of people with chronic pain report problems sleeping. We aimed to evaluate the effectiveness of non-pharmacological sleep interventions for improving sleep in people with chronic pain.

Design: We conducted a systematic review of non-pharmacological and non-invasive interventions to improve sleep quality or duration for adults with chronic non-cancer pain evaluated in a randomised controlled trial. Our primary outcome of interest was sleep; secondary outcomes included pain, health-related quality of life, and psychological wellbeing. We searched the Cochrane Library, MEDLINE, Embase, PsycINFO and CINAHL from inception to April 2020. After screening, two reviewers evaluated articles and extracted data. Meta-analysis was conducted using a random effects model. Risk of bias was assessed with the Cochrane tool.

Results: We included 42 trials involving 3346 people randomised to 94 groups, of which 56 received an intervention targeting sleep. 10 studies were of fair and 32 of good methodological quality. Overall risk of bias was judged to be low in 11, high in 10 and unclear in 21 studies. In 9 studies with 385 people randomised, cognitive behavioural therapy for insomnia showed benefit post-treatment compared with controls for improved sleep quality, standardised mean difference - 1.23 (95%CI -1.76, - 0.70; p < 0.00001). The effect size was only slightly reduced in meta-analysis of 3 studies at low risk of bias. The difference between groups was lower at 3 and 6 months after treatment but still favoured cognitive behavioural therapy for insomnia. Pain, anxiety and depression were reduced post-treatment, but evidence of longer term benefit was lacking. There was no evidence that sleep hygiene interventions were effective in improving sleep and there was some evidence in comparative studies to suggest that cognitive behavioural therapy for insomnia was more effective than sleep hygiene. Numerous other interventions were evaluated in small numbers of studies, but evidence was insufficient to draw conclusions about effectiveness.

Conclusions: Cognitive behavioural therapy for insomnia is an effective treatment to improve sleep for people with chronic pain, but further high-quality primary research is required to explore combined CBT content that will ensure additional improvements to pain, quality of life and psychological health and longer-term maintenance of benefits. Primary research is also needed to evaluate the effectiveness of interventions for which insufficient evidence exists.

Trial registration: PROSPERO registration number: CRD42019093799 .