Review of systematic reviews about the efficacy of non-pharmacological interventions to improve sleep quality in insomnia

Background Insomnia is a very common condition in various populations. Non-pharmacological interventions might offer (safe) alternatives for hypnotics. Aim To evaluate the evidence for efficacy from systematic reviews about non-pharmacological interventions to improve sleep quality in insomnia by a systematic review of systematic reviews and meta-analyses. Search strategy Search strategies were conducted in the Database of Abstracts of Reviews of Effects (2002-July 2008), The Cochrane Database of Systematic Reviews (2000-July 2008) and PubMed (1950-July 2008). Sleep quality was the outcome measure of interest. Selection criteria Systematic reviews about the efficacy of one or more non-pharmacological interventions for insomnia, concerning both adult and elderly populations, were included. Reviews that included studies performed among populations suffering with severe neurological or cognitive impairments or with addictive disorders were excluded. Data analysis Relevant data were extracted. The quality of the reviews found was appraised by using the Overview Quality Assessment Questionnaire. The evidence was appraised and divided into six classes. Results and conclusions Sixteen reviews about 17 interventions were included. Six reviews were of adequate methodological quality. Of these, only one provided an effect size: a moderate effect was found for music-assisted relaxation. Weak evidence indicating a large effect was found for multicomponent cognitive behavioural therapy, progressive muscle relaxation, stimulus control and 'behavioural only'. Weak evidence indicating a moderate effect was found for paradoxical intention. Finally, weak evidence indicating a moderate to large effect was found for relaxation training. Because of the lack of sufficient methodological quality and the lack of calculated effect sizes, most of the included reviews were not suitable for drawing rigorous conclusions about the effect of nonpharmacological interventions on sleep quality in insomniacs. The non-pharmacological treatment of insomnia would benefit from renewed reviews based on a rigorous methodological approach.