CONsensus-based Process evaluation reporting guideline for Public HEalth intervention Studies (CONPHES) conducted alongside effectiveness trials

Background: Many researchers conduct a process evaluation alongside an effectiveness trial of a public health intervention. Yet, there are no standardized, scientifically accepted guidelines for reporting such process evaluations, which impedes interpretation and comparison of study results.
Purpose: The aim of this project was to develop a consensus- and expert-based guideline for reporting process evaluations of public health interventions conducted alongside an effectiveness trial.
Methods: We conducted an e-Delphi study with 73 international experts. Based on a scoping review, we proposed 32 items to panel members. In the subsequent two rounds, adjustments to the items and descriptions were proposed to the e-Delphi panel until consensus of ≥67% for each individual item was reached.
Results: Based on purposive sampling, we invited 137 experts of which 73 (53%) participated in at least one round of the e-Delphi study. In total, 64 (88% of 73) completed round 2 and 55 (76% of 73) completed round 3. This resulted in 19 items that are included in the CONPHES guideline. Items include the description of the intervention, as well as the implementation strategies applied, and the role of the delivery and support team. The guideline also includes describing what framework was used for evaluation and how evaluation outcomes were assessed. The guideline is accompanied with an Explanation and Elaboration (E&E) document.
Conclusions: The CONPHES reporting guideline can improve the reporting of process evaluations of interventions aimed at promoting public health.
Practical implications: CONPHES can assist authors who are writing a process evaluation manuscript, or those writing the protocol for their planned process evaluation, and can be used by editors and reviewers to check if all necessary process evaluation information is described.
Funding: This project was funded by the HBCD Project and Working Group Grant 2019 of the Amsterdam Public Health research institute.