[Patient and public involvement in health-related research: How is the selection of participants reported?]

Background and objectives: In recent years, the reporting on patient and public involvement (PPI) in health-related research has gained significantly in importance. However, little attention is being paid to the selection of target groups or participating citizens and patients. Individual contributions already point out that the selection is often described in a complex but ambiguous way; for example, individual groups are often not sufficiently differentiated from each other. The aim of our study is to provide an overview of the main topics, questions and challenges that are specific to the selection of participants in PPI by means of an explorative sample of different PPI documents (studies with PPI, studies on PPI, PPI guidelines, PPI websites, PPI journals). Based on this overview, we will make recommendations to help authors of studies and other relevant stakeholders in the planning, implementation and reporting of participant selection.

Methods: First, the explorative sample of the above-mentioned PPI documents was identified by conducting a systematic database and online search. A total of 46 documents were taken into account, including 11 studies with PPI, 12 studies on PPI, 12 guidelines, 6 websites and 5 journals. Relevant text passages were extracted from each of them and evaluated using deductively and inductively developed topic-specific categories.

Results: Overall, the selected PPI documents significantly vary a) in the use of terms, b) in the detailing of the individual aspects of participant selection, and c) in the description of the planning and implementation of participant selection. For the latter, there is usually a lack of systematic, comprehensive explanations, e. g., on how to weigh up a relevant number of participants, on objectives and methods in the selection process and on how to prepare participants.

Discussion: The various documents about and contributions to the topic of PPI should, in future, report more transparently and systematically on the selection of participants, especially to create practical added value for authors of studies. This includes, in particular, the description of the selection (studies with PPI), a complete overview of all relevant steps of the selection process (PPI guidelines), recommendations on how to deal with representativeness (studies on PPI), notes on reporting PPI (journals) as well as overviews of individual steps of the implementation process (PPI websites).