What is a Realist Literature Review?

Understanding how, why, and under what circumstances complex interventions work is crucial for making informed decisions and policies. Realist reviews offer a robust methodology to achieve this by focusing on the mechanisms, contexts, and outcomes of interventions. They delve deeper to explore the intricate dynamics that contribute to an intervention’s success or failure.

Realist reviews, also known as realist syntheses, are a type of literature review that aims to explain how and why interventions, such as complex policy interventions, work in specific contexts. They focus on the underlying mechanisms of action, the contexts in which these mechanisms operate, and the outcomes they produce. The primary purpose of a realist review is to provide a nuanced understanding of the complex interactions between interventions and their contexts. Realist reviews seek to answer questions such as: What works for whom, in what contexts, and why? How do specific contexts influence the effectiveness of interventions? What are the key mechanisms that drive outcomes? It is rooted in realist philosophy, which emphasizes the importance of understanding the mechanisms through which interventions bring about outcomes and the contextual factors that influence these mechanisms.

These reviews help policymakers, practitioners, and researchers determine the effectiveness of an intervention and understand the conditions under which it can be most effective. Realist review methodology is designed to develop and refine program theories that explain the observed outcomes. These program theories explain how an intervention works in different contexts, and researchers can explore the particular mechanisms that generate outcomes while considering the influence of contextual factors.

Realist reviews are grounded in theories that explain how interventions are supposed to work. These theories are tested and refined throughout the review process. A central element of realist reviews is the identification of Context-Mechanism-Outcome configurations (Pawson and Tilley 1997). These configurations help explain how certain contexts trigger specific mechanisms, leading to particular outcomes. The review process is iterative, involving constant refinement of theories and conclusions as new evidence is analyzed. Realist reviews emphasize understanding causal relationships rather than merely identifying correlations between interventions and outcomes.

When to conduct a realist review?

Conducting a realist review is particularly advantageous when dealing with complex interventions involving multiple components and interactions. These interventions often do not yield straightforward results, and a realist synthesis can uncover the underlying mechanisms driving outcomes. This approach is especially useful in fields like healthcare, education, and social policy, where numerous factors interplay. When interventions are applied across diverse contexts, a realist review helps explain how different settings influence outcomes. If an intervention works well in one context but not in another, a realist synthesis can identify the contextual factors that affect its success or failure.

Realist reviews are also appropriate when there is a need to develop or refine theoretical frameworks explaining how interventions work. This theory-driven inquiry is beneficial in building a robust understanding of the underlying principles guiding effective interventions. When stakeholders need practical insights for program implementation or policy development, a realist review provides detailed explanations of what works, for whom, and under what circumstances. This type of review is valuable for policymakers, program developers, and practitioners requiring actionable knowledge. Lastly, in situations with limited or fragmented evidence, a realist review can synthesize available data to provide a coherent understanding of intervention mechanisms and contexts.