Addressing Deficits and Injustices: The Potential Epistemic Contributions of Patients to Research.

Patient or public involvement (PPI) in health research is increasingly expected as a matter of policy. In theory, PPI can contribute both to the epistemic aims intrinsic to research (generating knowledge), and to extrinsically valued features of research such as social inclusion and transparency. In practice, the aims of PPI have not always been clear, although there has been a tendency to encourage the involvement of so-called ordinary people who are regarded as representative of an assumed patient perspective. In this paper we focus on the epistemic potential of PPI, using theoretical work in epistemology to develop a nuanced account of patients' experiential knowledge and how this might contribute directly to conceptual development, hypothesis generation and data interpretation. We also consider how some features of health research pose barriers to this kind of epistemic contribution. Drawing on Miranda Fricker's idea of testimonial injustice, we explore how disciplinary indicators of credibility in clinical and academic health research contexts might be wrongly applied to those involved in PPI, undermining their potential to contribute. Finally we argue for a range of strategies to maximize opportunities for patients to engage with research teams and make epistemologically significant contributions to research.