A realist lens on implementation strategies: An opportunity for linking implementation and intervention processes and exploring unintended outcomes

This article argues that evaluation experts stand to benefit significantly from engaging with concepts and methodologies derived from both realist evaluation and implementation science. First, realist evaluation can facilitate the development of nuanced understandings of the intricate interplay among contextual factors, mechanisms of implementation strategies, and implementation outcomes. This enables evaluators to explore how, why, and under what circumstances implementation strategies work. Second, viewing the underlying workings of implementation strategies as ripple effects provides insight into their links with the implementation object, that is, the intervention itself. This provides insights into how implementation strategies can influence the workings of an implementation object. Third, realist evaluation allows for an exploration of unintended and unexpected outcomes, which are often overlooked in traditional evaluation frameworks. This is crucial as unforeseen effects may shape the generation of both implementation and client outcomes. These arguments are illustrated through theoretical and empirical reflections drawn from realist evaluation studies.