About this study
Pill-based pre-exposure prophylaxis using tenofovir disoproxil fumarate/emtricitabine and tenofovir alafenamide/emtricitabine are extremely effective at preventing HIV when used correctly. However, regular pill-taking may not be for everyone – it can be challenging to remember to take pills on time, for example, and for others, pill-taking can be challenging because of privacy concerns, inconvenience or other reasons. Fortunately, a variety of new HIV prevention products are currently in development, each with unique attributes that may appeal differently to different users. For example, long-acting injectable agents are on horizon, and efforts have long been underway to develop gels or other products that could be applied rectally. Understanding people’s preferences towards these various products and their characteristics can be useful to inform how they should be rolled out at the population level in the future.
A discrete choice experiment (DCE) is a survey-based method rooted in health economic and decision sciences theory that aims to quantify such preferences from the end-users’ perspective. We used a DCE to characterize preferences for existing and forthcoming PrEP modalities among gbMSM in Toronto, between May-August 2016.
Participants completed a survey containing 12 choice sets that comprised the DCE. Each choice set consisted of two hypothetical PrEP alternatives, and a status quo condition (Figure), and they were asked which of the three alternatives they most preferred. Each alternative was described by a set of attributes, each with a defined number of levels. We analyzed the results using a mixed multinomial logit model. To make the results of the statistical model more interpretable, we then ‘rescaled’ them so that each hypothetical form of PrEP could be given a final ‘utility’ score that measures the study sample’s overall preference for its corresponding combination of attributes.
Of 306 participants, most had heard of post-exposure prophylaxis (PEP, 77%) and pre-exposure prophylaxis (PrEP, 91%), but only 11% and 4% respectively had ever used them
Funding
This project was funded by CIHR.
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