Meta-analysis of psychological intervention for chronic pain: Challenges and Strategies for research quality improvement

 Aims and background: Chronic pain is a pervasive, destructive and expensive problem with a biopsychosocial nature. Psychological interventions suggested to be an effective choice for chronic pain, and many trials  confirmed its effectiveness and several meta-analyses have estimated the amount of its effect. Considering the psychological and social aspects of pain, it’s possible that the Iranian population respond differently to these interventions. Our goal is to evaluate the effectiveness of psychological interventions on pain intensity in Iranian adults with chronic pain by meta-analyzing domestic trials conducted. Materials and methods: We searched IranDoc, Element, and PubMed for eligible studies. Risk of bias assessed for each trial according to Cochrane collaboration guidelines. Total effect size estimated and possible moderators investigated. Findings: We found large effect sizes in both post treatment and follow up (d>0.80), but with significant heterogeneity among studies. Additional analyses suggested that researchers’ education levels have the most predictive effect with MA researchers reporting larger effect sizes than Ph.D. researchers. Conclusions: We speculate that the true effect size of psychological interventions is probably lower than what we estimated here and partly these results are functions of methodological errors or of biases. Considering the high number of researches in Iran it seems that few modifications could result in big progress in our literature. Some suggestions made for improving research protocols as well as analyses and reports.