The authors aimed to revise the Criteria for Reporting the Development and Evaluation of Complex Interventions in healthcare (CReDECI); a set of 16 best-practice guidelines published in 2012. The research design was essentially a survey conducted in three stages.
The first stage involved recruiting 38 researchers from a European research network to provide feedback about the CReDECI via an online questionnaire. Subsequently, the authors used the data to produce a draft version of the revised guidance.
The second stage was conducted in Slovakia during a masterclass on complex-intervention research. All attendees were invited to participate in a face-to-face consultation, in addition to the 38 researchers that participated in the online questionnaire. 45 participants were included in this stage; all of whom were researchers with experience of developing and evaluating complex interventions. Participants were supplied with the data collected in the first stage and a copy of the draft revision. They proposed amendments which were used by the authors to develop a final draft.
The third stage involved circulating the final draft to everyone who had participated in the previous two stages. After gathering feedback from the participants, the authors produced the final version of the guidance (CReDECI2). This comprised a checklist of 13 items divided into three categories: development; feasibility and piloting; and evaluation. Each item included a description about what to report (e.g. the first item calls for researchers to report the theoretical underpinnings of the intervention). Each item also includes a relevant extract from a published research study, to illustrate best practice.
The authors argued the CReDECI2 has the potential to improve the reporting quality of complex-intervention research as studies have suggested this is often not sufficient. They noted the CReDECI2 is different to the majority of other reporting guidelines as it does not focus exclusively on the evaluation stage of research and does not provide guidance tied to a specific research design. Therefore, they recommended using the CReDECI2 to report on all complex-intervention research, regardless of the underlying methodology. They also recommended using it alongside other reporting guidelines, such as the CONSORT Statement for randomised controlled trials.
A major strength was that the guidance was revised collaboratively with researchers in the field as these are the people who will most likely be using it and, therefore, best placed to suggest improvements. Arguably, this is illustrated by the decision to include accompanying examples from real studies as these have the potential to clarify the standard of reporting expected.
Unfortunately, the authors did not report how the researchers from the European research network were selected and, therefore, it is possible the sample was not representative. Furthermore, the authors did not detail how the feedback from each stage was incorporated into the guidance and how they managed conflicting opinions. It would have been useful to know if the authors used a systematic process to ensure they followed the views of the majority. If not, it is plausible the process was more of a consultation than a consensus.