An introduction to realist evaluation and synthesis for kidney research.

Realist research describes a methodological approach that aims to explore how and why interventions work, for whom, and under what circumstances. Rather than quantifying how well an intervention works under specific conditions, realist theory explores the function of interventions in detail and specifically considers how the contexts in which interventional components are delivered influence the mechanisms that lead to outcomes. Realist methods can be applied to primary data (realist evaluation) or secondary data (realist synthesis). Although realist techniques are increasingly being used in the evaluation of complex interventions, there are relatively few published studies in the field of kidney care. In this review, we outline the theory and principles behind realist methods through discussion of a published realist synthesis describing complex interventions promoting delivery of optimal chronic kidney disease care. We discuss other kidney studies that have used realist methodology and situations where realist techniques could be applied to advance our understanding of how to best deliver care to patients with kidney disease.