Meta-analyses are systematic summaries of research that use quantitative methods to find the mean effect size (standardized mean difference) for interventions. Critics of meta-analysis point out that such analyses can conflate the results of low- and high-quality studies, make improper comparisons and result in statistical noise. All these…

This article defines the "critical realist review", a literature-based methodological approach to critical analysis of health care studies (or any discipline charged with social interventions) that is robust, insightful and essential for the complexities of twenty-first century evidence-based health and social care. We argue that this…