Effects of mirror therapy on phantom limb sensation and phantom limb pain in amputees: A systematic review and meta-analysis of randomized controlled trials

Objective: This systematic review and meta-analysis aimed to evaluate the effects of mirror therapy on phantom limb sensation and phantom limb pain in amputees. Data sources: Nine electronic databases (PubMed, EMBASE, MEDLINE, Web of Science, the Cochrane Library, CINAHL, PsycInfo, PreQuest, PEDro) were searched from their inception to May 10th, 2021. Methods: Two authors independently selected relevant studies and extracted the data. The effect sizes were calculated under a random-effects model meta-analysis, and heterogeneity was assessed using the I-2 test. The risk of bias was evaluated by the Cochrane risk of bias tool, and the methodological quality was appraised by the PEDro scale. The GRADE approach was applied to assess the confidence of the effect. Results: A total of 11 RCTs involving 491 participants were included in this review and nine RCTs involving 372 participants were included in meta-analysis. The quality of these studies was from poor to good with scores ranging from 2 to 8 points according to PEDro scale. The pooled SMD showed that mirror therapy reduced the pain with a large effect size (-0.81; 95% CI = -1.36 to -0.25; P = 0.005; I-2 = 82%; n = 372) compared with other methods (four covered mirror, one phantom exercise, three mental visualization, one sensorimotor exercise, one transcutaneous electrical nerve stimulation, one tactile stimuli). The quality of evidence for the outcome pain intensity was determined to be fair according to GRADE approach. Conclusion: There is fair-quality evidence that MT is beneficial for reducing phantom limb pain.