PPI Costs

Outcomes or impacts of PPI such as improved study relevance or better recruitment are explicitly not treated as costs. The protocol defines costs broadly as resources consumed or burdens incurred to enable meaningful PPI, encompassing financial, time-related, emotional, organisational, and infrastructural inputs. Indirect costs of PPI include time, emotional labour, administrative delays, and coordination. Direct costs of PPI include reimbursement, travel, accessibility support, training, and technology. Reporting of PPI costs is especially weak for indirect and less visible costs such as emotional labour, unpaid preparation time, researcher coordination time, administrative burden, and governance delays. The question of how to account for PPI involvement costs emerged from prior stroke and aphasia PPI and co-creation projects in which both researchers and PPI partners identified uncertainty. Under-reporting of PPI costs may constrain what can be mapped in the scoping review.