What do we want to get out of this? a critical interpretive synthesis of the value of process evaluations, with a practical planning framework

Background: Process evaluations aim to understand how complex interventions bring about outcomes by examining intervention mechanisms, implementation, and context. While much attention has been paid to the methodology of process evaluations in health research, the value of process evaluations has received less critical attention. We aimed to unpack how value is conceptualised in process evaluations by identifying and critically analysing 1) how process evaluations may create value and 2) what kind of value they may create. Methods: We systematically searched for and identified published literature on process evaluation, including guidance, opinion pieces, primary research, reviews, and discussion of methodological and practical issues. We conducted a critical interpretive synthesis and developed a practical planning framework. Results: We identified and included 147 literature items. From these we determined three ways in which process evaluations may create value or negative consequences: 1) through the socio-technical processes of'doing' the process evaluation, 2) through the features/qualities of process evaluation knowledge, and 3) through using process evaluation knowledge. We identified 15 value themes. We also found that value varies according to the characteristics of individual process evaluations, and is subjective and context dependent. Conclusion: The concept of value in process evaluations is complex and multi-faceted. Stakeholders in different contexts may have very different expectations of process evaluations and the value that can and should be obtained from them. We propose a planning framework to support an open and transparent process to plan and create value from process evaluations and negotiate trade-offs. This will support the development of joint solutions and, ultimately, generate more value from process evaluations to all.