Triangulating patient and public involvement in clinical research: a cross-cohort qualitative study

Patient and Public Involvement (PPI) is widely endorsed within UK clinical research as both an ethical expectation and a mechanism for enhancing research relevance and quality. However, questions remain regarding how involvement functions in practice across institutional settings. Most studies examine PPI from single stakeholder perspectives, limiting understanding of how involvement is experienced across research systems. The DANIELLE study was co-produced with an established cancer PPI group and aimed to triangulate perspectives from multiple actors to examine how PPI is valued, evidenced and sustained within clinical research governance.

A qualitative multi-cohort design was used. Forty semi-structured interviews were conducted with purposively sampled participants, including lay PPI contributors, clinical trial sponsor staff, professional PPI leads and Research Ethics Committee members. Participants were recruited through established PPI networks, NHS research governance contacts and professional research channels. Data were analysed using reflexive thematic analysis, with cross-cohort triangulation employed to identify shared structural patterns. Reflexive and co-production principles informed study design and interpretation.

Five interconnected themes were generated: (1) PPI as ethically essential but structurally fragile; (2) authenticity versus performative compliance; (3) evidentiary gaps and the invisibility of contributor labour; (4) timing of involvement as a marker of authenticity; and (5) reliance on individual goodwill rather than institutional infrastructure. Across cohorts, participants described strong ethical commitment to involvement alongside systemic weaknesses in how experiential contributions are documented, recognised and sustained.

The findings suggest that persistent challenges in PPI reflect features of research system design rather than isolated failures of engagement. Strengthening involvement requires movement from rhetorical endorsement toward infrastructural integration, including improved approaches to evidencing influence and earlier positioning of contributors within research development pathways. By triangulating stakeholder perspectives through a co-produced inquiry, the study conceptualises PPI as a shared system-level knowledge practice rather than an optional enhancement to research delivery.