Detail

Realist Review

Realist Reviews seek to understand the underlying mechanisms of complex interventions and how these mechanisms interact with different contexts to produce varying outcomes, often incorporating a broader range of evidence and theories.

Purpose:

To Understand Complex Interventions: The primary aim is to understand how and why complex interventions work (or do not work) in particular contexts and for specific populations.
To Explore Mechanisms and Contexts: To explore the underlying mechanisms through which interventions produce their effects and how these effects are influenced by different contexts.

Literature searching for a realist review attempts to uncover just enough evidence to answer the question: i.e., ‘theoretical saturation’ and looks for specific mechanisms which might be found in various subject areas/populations, for example, school league tables might tell you about hospital league tables. (Realist and Realistic! searching: Where do I start and how far do I go? Dr Andrew Booth https://www.youtube.com/watch?v=ui4SH3z03P0&t=631s)

Information specialist support is probably needed throughout the process as literature searching can happen at any time as ideas are refined, not solely at the beginning as in a typical systematic review.

Characteristics:

Theory-Driven: Based on realist principles, which emphasise the importance of theories in explaining how interventions operate within specific contexts. It often seeks to test and refine theories about how and why interventions work.
Contextual Analysis: Focuses on understanding the interplay between the context, mechanisms, and outcomes. It aims to identify which contexts are conducive to success or failure of interventions.
Iterative Process: Involves an iterative process of searching, reviewing, and synthesising evidence. The review may evolve as new insights are gained, and theories are refined.
Mixed Evidence Sources: May include both quantitative and qualitative studies, as well as grey literature, to provide a richer understanding of the intervention and its context.
Flexibility: The process is less rigid than systematic reviews and can adapt to the complexities of the evidence being reviewed. It often incorporates a broad range of evidence types to build a comprehensive understanding.
Focus: Aims to provide insights into the mechanisms through which interventions impact outcomes, considering how different factors contribute to success or failure across various contexts.

Timescale:

6 to 12 months or more: Realist reviews usually take between 6 and 12 months, but this can extend depending on the complexity and the iterative nature of the review.

Example

Example: Realist Review on the Delivery of Health Services

This review exemplifies how the realist approach can be used to understand how and why complex interventions work (or don't work) in different contexts.

Title: Realist review – a new method of systematic review designed for complex policy interventions

Authors: Ray Pawson, Trisha Greenhalgh, Gill Harvey, Kieran Walshe

Published In: Journal of Health Services Research & Policy, 2005

Purpose: The primary aim of this realist review was to develop and refine a theoretical framework that explains how health services delivery interventions work, for whom, and under what circumstances. The focus was on understanding the mechanisms that generate outcomes in different contexts.

Key Characteristics of the Review:

Theory-Driven Approach: The review was driven by the aim to develop and test theoretical frameworks or explanations. It sought to understand the underlying mechanisms of interventions and how they interact with various contexts to produce outcomes.
Iterative Process: The review followed an iterative process of searching for evidence, extracting data, and refining theories. This cyclical approach allowed the reviewers to continually refine their understanding and explanations.
Context-Mechanism-Outcome (CMO) Configurations: The review focused on identifying CMO configurations, which are key to realist reviews. This involves understanding the contexts in which interventions are implemented, the mechanisms through which they operate, and the outcomes they produce.
Diverse Evidence Sources: The review included a wide range of evidence types, including qualitative studies, quantitative studies, policy documents, and grey literature, to develop a comprehensive understanding of the interventions.
Explanatory Focus: Unlike traditional systematic reviews that primarily focus on effectiveness, the realist review aimed to explain how and why interventions work, emphasising the importance of context and mechanism.

Key Findings:

The review identified various mechanisms through which health service delivery interventions achieve their outcomes, such as changes in professional behaviour, patient engagement, and organisational change.
It highlighted the importance of context, showing that the success of interventions often depends on factors like the organisational culture, the resources available, and the specific needs of the patient population.
The review provided a refined theoretical framework that can be used by policymakers and practitioners to design and implement more effective health service delivery interventions by considering the key mechanisms and contexts identified.

Impact:

This realist review by Pawson and colleagues has significantly contributed to the field of health services research and policy. It has provided valuable insights into the complexity of health interventions and has helped to establish realist review as a robust method for synthesising evidence on complex interventions.

Summary:

This example demonstrates how a realist review can be effectively used to understand the complexity of health service delivery interventions. By focusing on the underlying mechanisms and contexts, this approach provides deeper insights into how interventions work and can inform more effective policy and practice decisions. The work of Pawson et al. has been influential in promoting the use of realist reviews in various fields, particularly for evaluating complex social and health interventions.

NIHR Example:

Recent Realist Review (from NIHR journals library database 30/7/2024)

Maben J, Taylor C, Jagosh J, Carrieri D, Briscoe S, Klepacz N & Mattick K. Causes and solutions to workplace psychological ill-health for nurses, midwives and paramedics: the Care Under Pressure 2 realist review. Health and Social Care Delivery 2024;12(9)

Funding: Health and Social Care Delivery Research (HSDR) Programme (Health and Social Care Delivery Research Volume: 12, Issue: 9, Published in April 2024) https://doi.org/10.3310/TWDU4109 https://www.journalslibrary.nihr.ac.uk/hsdr/TWDU4109/#/abstract

Video resources

Realist and Realistic! Searching: Where do I start and how far do I go? Dr Andrew Booth, a review methodologist and information specialist who focuses on realist synthesis, will be a friendly navigator to take participants through the six stages of the realist search as defined by himself with experienced information colleagues. These six stages map to the Pawson Time and Task Template and can be useful for those undertaking a full realist synthesis, those conducting a realist evaluation against a literature "backdrop" and those pursuing a hybrid evaluation/synthesis. Throughout the presentation the techniques and sources will be illustrated from over a dozen realist synthesis projects in which he has directly participated and from current practice elsewhere. (Dr Andrew Booth, ScHARR 1 hour 2:40 minutes)
Realist approach in research – an overview The video is aimed at early career researchers and those new to realist methodology. (NIHR ARC Kent Surrey Sussex 30:22 minutes)

Protocols and reporting guidance

Protocol

Protocol - realist and meta-narrative evidence synthesis: Evolving Standards (RAMESES)

Reporting guideline

Use the RAMESES checklist - Realist And Meta-narrative Evidence Syntheses: Evolving Standards (RAMESES) project. (19 items that should be included in a publication to ensure quality and transparency)

The full checklist (as a PDF) can be found on the NIHR Journals library website.
RAMESES publication standards for the reporting of a realist review.