Patient and public involvement and engagement in target trial emulation framework: a scoping review protocol

Target trial emulation (TTE) has emerged as a methodological framework to strengthen causal inference from observational health data when randomised controlled trials are infeasible. The credibility of TTE studies depends not only on rigorous design and transparent reporting, but also on their relevance and acceptability to patients and the public. Patient and public involvement and engagement (PPIE) has been shown to enhance the relevance, transparency and impact of health research by shaping research priorities, informing study design and ensuring outcomes reflect patient perspectives. However, the extent to which PPIE has been incorporated into TTE studies remains unclear. This scoping review aims to systematically map the use and reporting of PPIE in published TTE studies.

This review will follow the Joanna Briggs Institute methodology for scoping reviews and will be reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis extension for Scoping Reviews checklist. We will search MEDLINE (Ovid) and Embase (Ovid) from January 2011 to present, limited to English-language publications. Eligible studies will be studies that self-identify as using the TTE framework and report empirical analyses of health outcomes using observational or trial data. We will exclude protocols, methodological or simulation-only studies, preprints, conference abstracts and grey literature. Three reviewers will independently screen titles and abstracts, and then full texts, with disagreements resolved by discussion or adjudication. Data extraction will include study characteristics and PPIE information guided by the Guidance for Reporting Involvement of Patients and the Public 2-Short Form checklist. Findings will be summarised using descriptive statistics, tables, figures and narrative synthesis.

Ethics approval is not required, as this review will use publicly available data. Results will be disseminated through a peer-reviewed publication and presented at conferences.