Is mindfulness meditation effective for insomnia?
Date of publication of the systematic review: October 2016
Design
Systematic review of 6 randomized controlled trials (RCTs).
Participants
330 participants who were diagnosed with insomnia or sleep disorders or had a subjective complaint of sleep without a clinical diagnosis. The reviewers did not report mean age and gender proportion of the participants.
Intervention
Mindfulness meditation (MM) including mindfulness-based stress reduction (MBSR) and mindfulness-based cognitive therapy (MBCT) was performed. The treatment duration varied from 6 to 8 weeks. The reviewers did not report the frequency of the intervention.
Comparator
Comparison: MM versus waiting-list control or additional attention control groups.
Major Outcomes
Outcome 1: Sleep quality as measured after the intervention;
Outcome 2: Sleep onset latency (SOL) as measured after the intervention.
Settings
The reviewers did not state whether the study was performed in inpatient or outpatient settings.
Comparison    MM versus waiting-list control or additional attention control groups
Main Results
Compared to waiting-list control or additional attention control groups, MM significantly improved sleep quality (standardized mean difference (SMD): 0.68, 95% CI: 0.24 to 1.13) and significantly reduced scores of SOL (SMD: -0.53, 95% CI: -0.97 to -0.09).
Comparison: MM versus waiting-list control or additional attention control groups in patients with insomnia
Outcomes No. of studies (Total number of participants) Mean value (SD)/No. of participants Heterogeneity test (I2) SMD (95% CI) Overall quality of evidence*
Intervention Comparator
1 2 (83) Not reported Not reported Not reported 0.68 (0.24 to 1.13) Low
2 2 (83) Not reported Not reported Not reported -0.53 (-0.97 to -0.09) Low
Keys: SMD: standardized mean difference; CI: confidence interval.
Comparison    MM versus waiting-list control or additional attention control groups
Main Results
Compared to waiting-list control or additional attention control groups, MM significantly improved sleep quality (standardized mean difference (SMD): 0.68, 95% CI: 0.24 to 1.13) and significantly reduced scores of SOL (SMD: -0.53, 95% CI: -0.97 to -0.09).
Comparison: MM versus waiting-list control or additional attention control groups in patients with insomnia
Outcomes 1 2
No. of studies (Total number of participants) 2 (83) 2 (83)
Mean value (SD)/No. of participants Intervention Not reported Not reported
Comparator Not reported Not reported
SMD (95% CI) 0.68 (0.24 to 1.13) -0.53 (-0.97 to -0.09)
Overall quality of evidence* Low Low
Keys: SMD: standardized mean difference; CI: confidence interval.
Conclusion
Benefits
Compared to waiting-list control or additional attention control groups, MM provided significant beneficial effects on sleep quality and SOL among patients with insomnia. For all outcomes, the overall quality of evidence is low. Further research is likely to have an important impact on our confidence in this estimate of effect.
Harms
The reviewers did not provide details of adverse events in the included trials.
Link to Original Article
https://www.ncbi.nlm.nih.gov/pubmed/27663102.
The synopsis is based on the following article:
Gong H, Ni CX, Liu YZ, Zhang Y, Su WJ, Lian YJ, Peng W, Jiang CL. Mindfulness meditation for insomnia: A meta-analysis of randomized controlled trials. Journal of Psychosomatic Research. 2016 Oct 31;89:1-6.


* Interpretation of quality assessment results:
• Very low: Further research is most likely to have an important impact on our confidence in this estimate of effect.
• Low: Further research is likely to have an important impact on our confidence in this estimate of effect.
• Moderate: Further research is fairly likely to have an important impact on our confidence in this estimate of effect.
• High: Further research is unlikely to have an important impact on our confidence in this estimate of effect.
• Very high: Further research is most unlikely to have an important impact on our confidence in this estimate of effect.

Details of assessment method can be found at Chung VC, Wu XY, Ziea ET, Ng BF, Wong SY, Wu JC. Assessing internal validity of clinical evidence on effectiveness of CHinese and integrative medicine: Proposed framework for a CHinese and Integrative Medicine Evidence RAting System (CHIMERAS). European Journal of Integrative Medicine. 2015 Aug 31;7(4):332-41.