Efficacy and acceptability of 'nudges' aimed at promoting pre-exposure prophylaxis (PrEP) use: a survey of overseas born men who have sex with men.

Abstract

This study explores the potential for behavioural economics techniques called 'nudges' to encourage the use of HIV pre-exposure prophylaxis (PrEP) by overseas-born men who have sex with men (MSM) in Australia. We investigated the preferences of overseas-born MSM for different nudges and the effect of nudges on reported likelihood of seeking information about PrEP. We conducted an online survey of overseas-born MSM, in which they were asked: (1) how likely they and a relevant friend would be to click on PrEP advertisements that used behavioural economics strategies; and (2) what they most and least liked about each ad. We conducted ordered logistic regression of reported likelihood scores against participant age and sexual orientation, use of a model in an advertisement, use of statistics about PrEP, reference to the World Health Organization (WHO), rewards for seeking further information, and use of a call-to-action. Participants (n =324) reported higher likelihoods of clicking on advertisements with images of people, statistics about PrEP, rewards for seeking further information, and calls-to-action. They reported lower likelihoods of clicking on advertisements referencing the WHO. They had negative emotional responses to sexualised humour, gambling metaphors, and the slogan 'Live Fearlessly'. Overseas-born MSM prefer public health messages that feature representative messengers and statistics about PrEP. These preferences are consistent with previous data on descriptive norms (i.e. statistics about the number of peers doing the desired behaviour) and gain-framed information (i.e. focusing on what can be gained from an intervention).