Are mindfulness interventions effective for chronic pain and psychological comorbidity?
Date of publication of the systematic review: June 2014
Design
Systematic review of 8 randomized controlled trials (RCTs).
Participants
666 patients aged 18 years or above with pain for a minimum of three months or diseases with chronic pain symptoms. The reviewers did not report mean age and gender proportion of the participants.
Intervention
Mindfulness-based stress reduction (MBSR), mindfulness-based meditation, and other mindfulness-based interventions were used as interventions. Duration of intervention ranged from 6 to 8 weeks. The reviewers did not report frequency of the mindfulness session.
Comparator
Comparison: Mindfulness interventions versus waiting-list control, attention-placebo, usual care or educational instruction.
Major Outcomes
Outcome 1: Pain intensity as measured by McGill Pain Questionnaire- Short Form at the end of the intervention;
Outcome 2: Depression as measured by Beck Depression Inventory at the end of the intervention;
Outcome 3: Depression as measured by the Centre for Epidemiological Studies Depression Scale (CES-D) at the end of the intervention;
Outcome 4: Trait anxiety as measured at the end of the intervention.
Settings
The reviewers did not state whether the study was performed in inpatient or outpatient settings.
Comparison    Mindfulness interventions versus waiting-list control, attention-placebo, usual care or educational instruction
Main Results
Compared to waiting-list control, attention-placebo, usual care or educational instruction, mindfulness interventions showed no significant reduction in pain intensity as measured by McGill Pain Questionnaire- Short Form (pooled weighted mean difference (pooled WMD): -3.24, 95% CI: -8.92 to 2.45). However, mindfulness interventions showed significant reduction in depression as measured by Beck Depression Inventory (pooled WMD: -3.91, 95% CI: -5.94 to -2.32) and CES-D (pooled WMD: -3.21, 95% CI: -3.65 to -2.77). MBSR also showed significant effects on reducing trait anxiety in patients with chronic pain (pooled WMD: -4.07, 95% CI: -4.48 to -3.65).
Comparison: Mindfulness interventions versus waiting-list control, attention-placebo, usual care or educational instruction in patients with chronic pain
Outcomes No. of studies (Total number of participants) Mean value/No. of participants Heterogeneity test (I2) Pooled WMD (95% CI) Overall quality of evidence*
Intervention Comparator
1 3 (144) Not reported/76 Not reported/68 0% -3.24 (-8.92 to 2.45) Moderate
2 4 (229) Not reported/129 Not reported/100 0% -3.91 (-5.94 to -2.32) Low
3 3 (293) Not reported/144 Not reported/149 51% -3.21 (-3.65 to -2.77) Low
4 4 (256) Not reported/130 Not reported/126 0% -4.07 (-4.48 to -3.65) Low
Keys: WMD: weighted mean difference; CI: confidence interval.
Comparison    Mindfulness interventions versus waiting-list control, attention-placebo, usual care or educational instruction
Main Results
Compared to waiting-list control, attention-placebo, usual care or educational instruction, mindfulness interventions showed no significant reduction in pain intensity as measured by McGill Pain Questionnaire- Short Form (pooled weighted mean difference (pooled WMD): -3.24, 95% CI: -8.92 to 2.45). However, mindfulness interventions showed significant reduction in depression as measured by Beck Depression Inventory (pooled WMD: -3.91, 95% CI: -5.94 to -2.32) and CES-D (pooled WMD: -3.21, 95% CI: -3.65 to -2.77). MBSR also showed significant effects on reducing trait anxiety in patients with chronic pain (pooled WMD: -4.07, 95% CI: -4.48 to -3.65).
Comparison: Mindfulness interventions versus waiting-list control, attention-placebo, usual care or educational instruction in patients with chronic pain
Outcomes 1 2 3 4
No. of studies (Total number of participants) 3 (144) 4 (229) 3 (293) 4 (256)
Mean value/No. of participants Intervention Not reported/76 Not reported/129 Not reported/144 Not reported/130
Comparator Not reported/68 Not reported/100 Not reported/149 Not reported/126
Pooled WMD (95% CI) -3.24 (-8.92 to 2.45) -3.91 (-5.94 to -2.32) -3.21 (-3.65 to -2.77) -4.07 (-4.48 to -3.65)
Overall quality of evidence* Moderate Low Low Low
Keys: WMD: weighted mean difference; CI: confidence interval.
Conclusion
Benefits
Compared to waiting-list control, attention-placebo, usual care or educational instruction, mindfulness interventions showed no significant reduction in pain intensity. However, mindfulness interventions improved depression and trait anxiety in patients with chronic pain. For outcome 1, the overall quality of evidence is moderate. Further research is fairly likely to have an important impact on our confidence in this estimate of effect. For outcomes 2 to 4, 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
None of the included trials report on adverse events.
Link to Original Article
https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0076304/
The synopsis is based on the following article:
Song Y, Lu H, Chen H, Geng G, Wang J. Mindfulness intervention in the management of chronic pain and psychological comorbidity: A meta-analysis. International Journal of Nursing Sciences. 2014 Jun 30;1(2):215-23.


* 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.