Collaborative and consultative patient and public involvement in sexual health research: lessons learnt from four case studies

Objectives: Patient and Public Involvement (PPI) is increasingly mandated in health research. However, there is little guidance on conducting PPI for research on episodic infections, risk factors, hard-to-reach populations, or stigmatised behaviours. The aim of this paper is to address the gap in PPI guidance by illustrating different approaches to challenging PPI scenarios. Methods: Four case studies of sexual health research PPI, each of which discusses three stages of PPI (defining, accessing and engaging with lay advisors). Results: Researchers may need to use broadly define lay advisors; involving those with insight into population of interest can be beneficial. Alternative and multiple routes to access patients/public should be considered. Flexible means of engagement can enable lay advisors to contribute anonymously, remotely and/or opportunistically. Conclusions: Case studies may help researchers in sexual health (and other fields) to better meet the challenges of PPI for studies which concern hard-to-reach populations, episodic infections, risk factors, and stigmatised behaviours.