Introducing EMMIE: an evidence rating scale to encourage mixed-method crime prevention synthesis reviews

Abstract

Objectives: This paper describes the need for, and the development of, a coding system to distil the quality and coverage of systematic reviews of the evidence relating to crime prevention interventions. The starting point for the coding system concerns the evidence needs of policymakers and practitioners. Methods: The proposed coding scheme (EMMIE) builds on previous scales that have been developed to assess the probity, coverage and utility of evidence both in health and criminal justice. It also draws on the principles of realist synthesis and review. Results: The proposed EMMIE scale identifies five dimensions to which systematic reviews intended to inform crime prevention should speak. These are the Effect of intervention, the identification of the causal Mechanism(s) through which interventions are intended to work, the factors that Moderate their impact, the articulation of practical Implementation issues, and the Economic costs of intervention. Conclusions: Systematic reviews of crime prevention, and the primary studies on which they are based, typically address the question of effect size, but are often silent on the other dimensions of EMMIE. This lacuna of knowledge is unhelpful to practitioners who want to know more than what might work to reduce crime. The EMMIE framework is intended to encourage the collection of primary data regarding these issues and the synthesis of such knowledge in future systematic reviews.