BackgroundPatient and Public Involvement (PPI) is increasingly recognized as an essential aspect of clinical research, particularly for ensuring relevancy and impact of research to those most affected. This study addresses the gap in involving older patients, particularly nursing home residents, in the research process by exploring motivations, expectations, and experiences of nursing home residents in Bremen, Germany, involved in PPI for developing a clinical trial on polypharmacy.MethodsTwo Patient Advisory Boards (PABs) were established in nursing homes as part of the INVOLVE-Clin project. A Patient Advocate (PA) facilitated communication between nursing home residents and researchers. A qualitative case study approach was employed, involving semi-structured interviews and group discussions with nursing home residents and researchers. Data was analyzed using structured qualitative content analysis.ResultsThe study found varied motivations and expectations between nursing home residents and researchers. Nursing home residents valued the social interaction and the opportunity to voice their health concerns, while researchers aimed to incorporate patients’ perspectives into study design. The PA was considered crucial in facilitating communication between nursing home residents and researchers. Challenges included the complexity of the study topic and the need for methodological adjustments to suit nursing home residents´ cognitive abilities. Generally, PAB participation was experienced to provide mental stimulation and increased confidence among nursing home residents in discussing their medication management. The PAB’s influence led to the decision not to conduct a polypharmacy study.DiscussionThe findings underscore the importance of flexible approaches to PPI, particularly when involving older nursing home residents. Methodological adjustments, such as tailoring content and structure of PABs, and the inclusion of additional boards for diverse perspectives, are vital for effective involvement. The study also highlights the need for ongoing innovation in PPI methods to ensure meaningful engagement of older patients in clinical research.ConclusionThis study contributes essential insights into the practical implementation of PPI with nursing home residents, highlighting the need for patient-centric approaches that recognize their unique challenges and contributions. These findings are critical for shaping scientifically robust but also socially relevant and impactful research, especially in an aging society.