Elsevier

The Lancet HIV

Volume 5, Issue 8, August 2018, Pages e448-e456
The Lancet HIV

Articles
Community-level changes in condom use and uptake of HIV pre-exposure prophylaxis by gay and bisexual men in Melbourne and Sydney, Australia: results of repeated behavioural surveillance in 2013–17

https://doi.org/10.1016/S2352-3018(18)30072-9Get rights and content

Summary

Background

Pre-exposure prophylaxis (PrEP) has been rapidly rolled out in large, publicly funded implementation projects in Victoria and New South Wales, Australia. Using behavioural surveillance of gay and bisexual men, we analysed the uptake and effect of PrEP, particularly on condom use by gay and bisexual men not using PrEP.

Methods

We collected data from the Melbourne and Sydney Gay Community Periodic Surveys (GCPS), cross-sectional surveys of adult gay and bisexual men in Melbourne, VIC, and Sydney, NSW. Recruitment occurred at gay venues or events and online. Eligible participants were 18 years or older (face-to-face recruitment) or 16 years or older (online recruitment), identified as male (including transgender participants who identified as male); and having had sex with a man in the past 5 years or identified as gay or bisexual, or both. Using multivariate logistic regression, we assessed trends in condom use, condomless anal intercourse with casual partners (CAIC), and PrEP use by gay and bisexual men, controlling for sample variation over time.

Findings

Between Jan 1, 2013, and March 31, 2017, 27 011 participants completed questionnaires in the Melbourne (n=13 051) and Sydney (n=13 960) GCPS. 16 827 reported sex with casual male partners in the 6 months before survey and were included in these analyses. In 2013, 26 (1%) of 2692 men reported CAIC and were HIV-negative and using PrEP, compared with 167 (5%) of 3660 men in 2016 and 652 (16%) of 4018 men in 2017 (p<0·0001). Consistent condom use was reported by 1360 (46%) of 2692 men in 2013, 1523 (42%) of 3660 men in 2016, and 1229 (31%) of 4018 men in 2017 (p<0·0001). In 2013, 800 (30%) of 2692 men who were HIV-negative or untested and not on PrEP reported CAIC, compared with 1118 (31%) of 3660 men in 2016, and 1166 (29%) of 4018 in 2017 (non-significant trend).

Interpretation

A rapid increase in PrEP use by gay and bisexual men in Melbourne and Sydney was accompanied by an equally rapid decrease in consistent condom use. Other jurisdictions should consider the potential for community-level increases in CAIC when modelling the introduction of PrEP and in monitoring its effect.

Funding

Australian Government Department of Health, Victorian Department of Health and Human Services, and New South Wales Ministry of Health.

Introduction

Regular use of antiretroviral drugs as pre-exposure prophylaxis (PrEP) is highly effective for the prevention of HIV infection.1 WHO has recommended PrEP be made available to populations at high risk of HIV.2

In 2014–15, small demonstration projects were implemented in New South Wales and Victoria, Australia's most populous states, offering PrEP to people at high risk of HIV (predominantly gay and bisexual men).3, 4 Since March, 2016, large-scale implementation projects have enrolled more than 10 000 participants.

Concerns have been raised that risk compensation (decreased perceptions of HIV risk and less condom use) might undermine the effectiveness of PrEP.5, 6, 7 In recent systematic reviews of randomised trials,1, 8 no evidence was found of increased condomless sex by PrEP users, but participants in these studies were unaware whether they were receiving PrEP or a placebo. In open-label and cohort studies of PrEP users,9, 10, 11, 12 condomless sex had become more frequent over time, but this does not seem to diminish the efficacy of PrEP if drug adherence is maintained. Less attention has been paid to the population-level effect of PrEP on community norms and behaviour. In particular, if people feel safer, the introduction of PrEP might lead to decreased condom use by those not using PrEP (so-called community-level risk compensation).7 In San Francisco, CA, USA, condom use by gay and bisexual men, including those not using PrEP, decreased rapidly after PrEP was introduced.13, 14 The San Francisco researchers suggested that some men had given up consistent condom use under the assumption that other men will be using PrEP.13

Research in context

Evidence before this study

We searched PubMed for studies published in English before Dec 31, 2017, with the terms “HIV”, “pre-exposure” or “preexposure”, “prophylaxis”, “men who have sex with men” or “MSM” or “gay” or “bisexual”, “behaviour” or “behavior”, “surveillance” or “impact” or “change”, and “condom”. In two systematic reviews, the sexual behaviour of men who used pre-exposure prophylaxis (PrEP) in trials did not change significantly. In three open label studies and one cohort study, PrEP users used condoms less often over time, and in five mathematical models, the effect of decreased condom use was considered for PrEP users but not for other men who have sex with men (MSM). In one study from San Francisco, condom use at a community level (ie, by MSM not using PrEP) decreased as PrEP use increased. Evidence suggesting that community-level changes in behaviour is related to PrEP was lacking from other jurisdictions.

Added value of this study

Using annual behavioural surveillance of gay and bisexual men in Australia's largest cities, Melbourne, VIC, and Sydney, NSW, we analysed the uptake and effect of PrEP on sexual behaviour in 2013–17. We found a rapid increase in PrEP use, particularly in 2016–17, and a reduction of a similar magnitude in consistent condom use at a population level (ie, consistent condom use with casual partners decreased in men not using PrEP). Despite the reduction in condom use, the overall level of protection in the population increased slightly and new HIV diagnoses in MSM decreased.

Implications of all the available evidence

The introduction of PrEP might be accompanied by a decrease in condom use by non-PrEP users. This potential change has not been consistently assessed or accounted for in routine monitoring of MSM or in mathematical modelling. The degree to which community-level risk compensation might impede the long-term, population-level effectiveness of PrEP is unknown. We recommend improved monitoring and evaluation to assess the effect of PrEP on sexual behaviour at a community or population level.

Although decreased condom use by adherent PrEP users might have little effect on its efficacy in preventing HIV infection, decreased condom use by others could undermine the population-level effect of PrEP by increasing the number of unprotected sex acts during which transmission might occur. In San Francisco, annual HIV diagnoses in men who have sex with men (MSM) decreased by 55% between 2012 and 2016.14 This suggests that the uptake of PrEP might outweigh the effect of community-level increases in condomless sex on new HIV diagnoses. Mathematical modelling has been done to assess the potential effect of PrEP on HIV epidemics in MSM.15, 16, 17, 18, 19 However, although these models often assess scenarios in which PrEP users reduce condom use, they do not seem to consider the effect of non-PrEP-using MSM reducing condom use as PrEP uptake becomes more common.

In the context of rapidly increasing PrEP use in New South Wales and Victoria between 2016 and 2017, we adapted behavioural surveillance of gay and bisexual men to assess the effect of PrEP on condom use at a community level.20 Our aim was to assess the degree of community-level risk compensation, if any, and the potential need to refine combination prevention responses in these jurisdictions.

Section snippets

Participants and procedures

Data were collected in the Melbourne and Sydney Gay Community Periodic Surveys (GCPS). These behavioural surveillance studies have been done annually for more than 20 years during Melbourne's Midsumma Festival and Sydney's Gay and Lesbian Mardi Gras. We included data from the period 2013–17 to compare periods before (2013–16) and after (2017) widespread PrEP use. The GCPS methods have been described previously.20, 21 In brief, the GCPS use time–location sampling at gay venues and events, during

Results

Between Jan 1, 2013, and March 31, 2017, 27 011 participants completed questionnaires in the Melbourne (n=13 051) and Sydney (n=13 960) GCPS, of whom 16 827 reported having had sex with casual male partners in the 6 months before survey. The following analyses are restricted to these 16 827 participants.

The mean age of participants was 36 years (table 1). Most participants were recruited from gay social venues and events, identified as gay, and were Anglo-Australian. Small proportions reported

Discussion

By use of repeated behavioural surveillance in Australia's most populated metropolitan areas, we found a large increase in PrEP use from 2013 to 2017 (up to 24% of HIV-negative men) and an increase in men using PrEP who reported condomless sex with casual partners (increasing to 16% of men with casual partners in 2017). A similar magnitude reduction in consistent condom use with casual sex partners occurred during the same period. This change was concentrated in non-PrEP users because no PrEP

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