Despite decades of traditional prevention work based on behaviour change and condoms, unacceptably high rates of HIV transmission persist in Canada, with a disproportionate burden among men who have sex with men (MSM) and heterosexual African, Caribbean and Black (ACB) communities. In Ontario, MSM have long accounted for the vast majority of incident HIV cases, making up 67% of new HIV diagnoses in 2011. While much of the ACB epidemic is related to immigration, 20-60% of HIV diagnoses in ACB persons are thought to occur in Canada.
To address these challenges, there has been increasing interest in using new biomedical HIV prevention technologies (NPTs) such as Pre-Exposure Prophylaxis (PrEP). A key uncertainty regarding the implementation of NPTs is how to link these interventions to those who are most likely to use and benefit from them – a process that should incorporate the perspectives of both providers (including clinicians and policy-makers) and potential users (also referred to herein as ‘patients’). There is a growing body of research exploring how physicians should assess patients’ eligibility for NPTs based on risk, and how public health programs should similarly target individuals at greatest HIV risk. However, relatively less attention has been paid to understanding patient preferences regarding prevention options, which will ultimately determine both uptake and adherence. Careful collection and analysis of patient preference data will inform decision-making at multiple levels and be vital to maximizing the clinical and public health potential of PrEP and other NPTs.
This study sought to evaluate patient preferences on key attributes of NPTs among two high-risk populations in Ontario: sexually active a) MSM and b) heterosexual men and women from ACB communities. In part 1, we gathered and analyzed preference data using discrete choice experiments (DCEs), a method originally developed in marketing research that is increasingly used in health care decision-making. This method involves identifying attributes of interest (eg. route of administration); assigning levels to each attribute (eg. pill, depot injection, topical microbicide); creating a manageable number of representative scenarios combining these attributes and levels; establishing individuals’ preferences by presenting respondents with a series of choices between scenarios and having them indicate their preferences; and analyzing the data with regression techniques. We also conducted a series of one-on-one interviews exploring barriers and opportunities to engagement with NPTs, where questions were based on the findings from the DCE.
Our secondary objective was to estimate the influence of individuals’ preferences regarding NPT attributes on the potential population-level HIV transmission impact of NPTs in settings like Ontario. To do this, we used a dynamic mathematical model of HIV transmission, and estimated the sensitivity of NPT impact (ie. relative reduction in HIV incidence) to different permutations of NPT uptake by using the expected uptake associated with various NPT attributes from part 1. By coupling the rich demographic, behavioural and preference data gathered during part 1 with emerging evidence from clinical trials on known attributes of emerging NPTs, this analysis will provide unique and important policy insights into the optimal rollout strategies for NPTs to control the epidemic.
This study was made possible through a grant from CIHR.