A synthesis of meta-analyses of mindfulness-based interventions in pain

Mindfulness interventions have become popular in recent decades, with many trials, systematic reviews, and meta-analyses of the impact of mindfulness-based interventions (MBIs) on pain. Although many meta-analyses provide support for MBIs, the results are more mixed than they at first appear. The aim of this umbrella review was to determine the strength of evidence for MBIs by synthesizing available meta-analyses in pain. We conducted a systematic search in 5 databases and extracted data from published meta-analyses as the unit of analysis. For each outcome, we reported the range of effect sizes observed across studies and identified the largest meta-analysis as the "representative" study. We separately analysed effect sizes for different pain conditions, different types of MBIs, different control groups, and different outcomes. We identified 21 meta-analyses that included 127 unique studies. According to Assessment of Multiple Systematic Review ratings, the meta-analyses ranged from very strong to weak. Overall, there was an impact of MBIs on pain severity, anxiety, and depression but not pain interference or disability. When conditions were considered in isolation, only fibromyalgia and headache benefited significantly from MBIs. Mindfulness-based interventions were more efficacious for pain severity than passive control conditions but not active control conditions. Only pain severity and anxiety were affected by MBIs at follow-up. Overall, our results suggest that individual meta-analyses of MBIs may have overestimated the efficacy of MBIs in a range of conditions. Mindfulness-based interventions likely have a role in pain management but should not be considered a panacea.