An overview and investigation of relapse predictors in anorexia nervosa: a systematic review and meta-analysis

Abstract

Objective: An extensive number of predictors has been examined across the literature to improve knowledge of relapse in anorexia nervosa (AN). These studies provide various recovery and relapse definitions, follow-up durations and relapse rates. The current study summarizes these values and predictors of relapse in AN in a review and meta-analysis.Method: The study was executed according to PRISMA guidelines. Different databases were searched and studies in which participants did not receive an official clinical diagnosis were excluded. A quality analysis was performed using the National Institute of Health's Study Quality Assessment Tool. Random-effects meta-analyses were conducted to summarize data.Results: Definitions of relapse and recovery were diverse. During an average follow-up period of 31 months an average relapse rate of 37% was found. Predictive variables from 28 studies were grouped in six categories: age and sex, symptoms and behaviors, AN subtype and duration, weight or weight change, comorbidity, and personality. The studies were characterized by non-significant and contradictory results. Meta-analyses were performed for the predictors age, AN duration, pre-treatment BMI, post-treatment BMI and depression. These yielded significant effects for post-treatment BMI and depression: higher pre-treatment depression (SMD = .40 CI [.21-.59] and lower post-treatment BMI (SMD = -.35 CI [-.63 to -.07]) increased relapse chances in AN.Discussion: Our results emphasized a lack of sufficiently powered studies, consistent results, and robust findings. Solely post-treatment BMI and pre-treatment depression predicted relapse. Future research should use uniform definitions, larger samples and better designs, to improve our understanding of relapse in AN.Public significance: Knowledge about predictors is important to understand high relapse rates. Our study performed a review and meta-analysis of relapse predictors in AN. Related to the heterogeneity in studies examining predictors, an overview of relapse and recovery definitions, follow-up durations and relapse rates for AN was provided. Significant effects were found for post-treatment BMI and pre-treatment depression. More studies with uniform definitions are needed to improve clinical implications.