International practices, barriers, and enablers for patient and public involvement in pricing and reimbursement decision-making: a mixed-methods study.

Introduction: Patient and public involvement (PPI) in pricing and reimbursement (P&R) procedures is increasingly recognized as essential for strengthening the quality, legitimacy, and patient-centredness of healthcare decision-making. However, implementation remains heterogeneous across countries and data on concrete practices, barriers, and enablers are fragmented. This study aimed to map international approaches to PPI in P&R procedures and identify barriers and enablers to meaningful involvement. Methods: A mixed-methods design was applied, combining a scoping literature review complemented by qualitative research. The scoping literature review was conducted following PRISMA-ScR guidance to identify scientific publications on PPI in P&R procedures. Semi-structured interviews and focus group discussions were conducted with industry experts, policymakers, assessors, and patient organisations. A descriptive, narrative, and thematic analysis integrating findings across data sources identified recurring patterns, cross-country similarities and differences, and diverse stakeholders' perspectives. Results: The literature and stakeholder perspectives revealed that PPI remains uneven and inconsistently implemented in P&R procedures across healthcare systems, though overall trends point towards more structured participation and partnership. Barriers include: (i) resource constraints, (ii) unclear value and impact of PPI, (iii) conflict of interest and confidentiality concerns, (iv) recruitment challenges, (v) concerns about representativeness and diversity, (vi) complexity of P&R terminology and processes, (vii) methodological gaps, (viii) limited experience with PPI, and (ix) competing workloads. Across countries, stakeholders identified a shared set of enabling conditions necessary for meaningful involvement: (i) clear institutional commitment and leadership, (ii) dedicated resources, time, and experience-building with explicit definition of roles, expectations, and scope of influence, (iii) transparency and systematic feedback for two-way communication, (iv) methodological rigour and evaluation frameworks for capturing and reporting experiential evidence, (v) inclusivity and representativeness with diverse participation opportunities, and (vi) capacity building for both patients and the public, as well as P&R agencies. Conclusion: While PPI in P&R procedures remains uneven across countries, there is a clear shift towards more structured participation. Meaningful and sustainable involvement requires the integration of structural, organisational, procedural, technical, and financial enablers. When these enablers are aligned and mutually reinforcing, PPI can become a substantive driver of more patient-centred, transparent, and socially accountable P&R decision-making.