Realist Trials and Systematic Reviews: Rigorous, Useful Evidence to Inform Health Policy

This book describes an innovative approach to the evaluation of complex health interventions, assessing what interventions work, how and for whom. Rejecting the stalemate between trials and realist evaluation, it draws on the best of both. Randomised controlled trials and systematic reviews offer the least biased means of assessing intervention effects but tell us little scientifically about how interventions work. Policy-makers and practitioners are also not supported to decide which interventions are likely to achieve most benefits in their local contexts. Realists use other forms of evaluation and evidence synthesis exploring how intervention mechanisms interact with context to generate outcomes. But these approaches lack rigour in assessing causality. This book proposes how realist evaluation methods may be incorporated within randomised controlled trials and systematic reviews. This enables evaluations and evidence synthesis to benefit from the more nuanced questions posed within realist enquiry while maintaining rigour in assessing causality.

Chris Bonell is Professor of Public Health & Sociology in the Department of Public Health, Environments and Society, London School of Hygiene and Tropical Medicine. His research mainly focuses on adolescent health, sexual health and violence. He was involved in scientific advice to the UK government during the Covid-19 pandemic, particularly in the areas of communication strategies and school interventions.

G. J. Melendez-Torres is Professor of Clinical and Social Epidemiology at the University of Exeter, where he also holds the citiesRISE Research Chair in Public Mental Health. A registered nurse, his research is primarily in epidemiology and evaluation in child and adolescent health and in intimate partner violence.

Emily Warren is an Assistant Professor at the London School of Hygiene and Tropical Medicine, where she evaluates public policies and complex interventions using realist approaches. She is a recipient of the European Society for Prevention Research Presidents' Award in recognition of her work on the philosophical compatibility and feasibility of realist RCTs.