AJPH PREEXPOSURE PROPHYLAXIS Individual Versus Community-Level Risk Compensation Following Preexposure Prophylaxis of HIV We analyzed the concept of risk Martin Holt, PhD, and Dean A. Murphy, PhD compensation and how it has been applied in HIV prevention, See also Landers and Kapadia, p. 1534. to consider the impact of PrEP on paying particular attention to community norms and practices the strategy of HIV preexposure and not only on the immediate reexposure prophylaxis and safety and recalibrate their prophylaxis (PrEP). In risk com- recipients of the intervention. P (PrEP) is one of the most actions if they perceive that pensation, reduced perceptions Risk compensation theory significant developments in HIV they are exceeding their target of risk after the introduction relies on a rational actor model prevention, providing an al- or acceptable level of risk. A of a preventative intervention of human behavior, which is ternative and supplement to pre- key part of risk compensation derived from classic economic lead to more frequent risk- vention methods such as theory is that the benefits of an theory and has not been without taking behavior. Such a change condoms. PrEP involves intervention (e.g., seatbelts) can its critics.9,10 The idea that risk may undermine the interven- HIV-negative people regularly be outweighed over time as compensation is inevitable is tion’sprotectivebenefits. taking antiretroviral drugs to people begin to feel safer and contested, particularly when We found that many studies prevent HIV infection.1,2 It has then increase their risk-taking highly effective interventions purporting to investigate risk been found to be highly effective behavior (e.g., driving faster or are introduced. Also, it is not in preventing HIV acquisition more dangerously). The theory compensation do not assess or straightforward to measure contends that an intervention report changes in perceptions of in multiple population groups, people’stargetlevelsofrisk, may fail unless the target or ac- risk, instead relying on behavioral particularly gay and bisexual men, making the theory difficult to ceptable level of risk is reduced, measures. Our analysis suggests as long as recipients regularly take test. Because of the variability that is, unless people are moti- a complex and sometimes coun- the prescribed drugs (at least in findings (in road safety and 3 vated, educated, or incentivized terintuitive relationship between four doses per week). However, other areas), researchers suggest the development of PrEP has to behave more prudently. the introduction of a new pre- that more attention needs to not been without controversy. vention intervention, perceptions be paid to the conditions under Before the efficacy of PrEP was of HIV risk, and subsequent which risk compensation does demonstrated, researchers were and does not occur. changes in behavior. already concerned that “PrEP RISK COMPENSATION As PrEP is introduced, we be- may be used as a justification for We considered how risk lieve comprehensive assessment of increasing the frequency or types compensation has been used in community-level risk compen- of risk-taking behaviors, which the HIV field, particularly in sation—that is, changes in risk could result in higher rates of relation to PrEP. We discuss RISK COMPENSATION perceptions and behavior as sexually transmitted infections the theory of risk compensation AND HIV a result of increased optimism and fuel HIV transmission.”4(p864) and how it has been measured. Risk compensation has gar- about avoiding HIV among The concept of increased risk We suggest alternative ways to nered attention as a way to un- people not directly protected by taking undermining the effective- assess the impact of PrEP, in- derstand why the uptake of “ PrEP—should not be omitted. ness of an intervention is often cluding evaluating prevention HIV prevention measures “ optimism.” We argue that re- sometimes fail to achieve a re- We therefore suggest ways to referred to as risk compensa- ”5,6 searchers and evaluators need duction in HIV infections assess prevention optimism tion, and the implementation of PrEP has intensified debates and community-level risk com- about it. ABOUT THE AUTHORS pensation. (AmJPublicHealth. Risk compensation is a con- Martin Holt and Dean A. Murphy are with the Centre for Social Research in Health, 2017;107:1568–1571. doi:10.2105/ University of New South Wales, Sydney, Australia. Dean A. Murphy is also with the cept derived from risk homeo- Department of Gender and Cultural Studies, University of Sydney, Australia. AJPH.2017.303930) 7,8 stasis theory. It suggests that Correspondence should be sent to Martin Holt, Centre for Social Research in Health, Level 2, people continually evaluate the John Goodsell Building, UNSW Sydney, NSW 2052, Australia (e-mail: [email protected]. fi au). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. potential risks and bene ts of This article was accepted May 16, 2017. their actions for their health doi: 10.2105/AJPH.2017.303930 1568 Commentary Peer Reviewed Holt and Murphy AJPH October 2017, Vol 107, No. 10 AJPH PREEXPOSURE PROPHYLAXIS and as something to monitor when randomized trials in Africa have PREEXPOSURE which is higher than in the introducing new interventions.5,6 foundlittleevidencethatmed- PROPHYLAXIS AND placebo-controlled phase.1 A It has been investigated in relation ical male circumcision leads to RISK COMPENSATION large, open-label trial in the to condoms, HIV treatment, male increased sexual activity or more United Kingdom found that 15,16 PrEP researchers were cog- circumcision, and PrEP as well condomless sex. nizant of the potential for risk PrEP reduced the risk of HIV as potential future strategies (e.g., Fourth, changes in behavior fi infection by 86% among gay and compensation, and the rst large 22 microbicides and vaccines). IfHIV may be rendered irrelevant be- randomized controlled trials bisexual men and that after one interventions lead to a reduced cause a prevention strategy is so year PrEP users were more likely monitored the sexual behavior perception of risk and subsequent effective that there is little chance than were nonusers to report of participants over time.1,2,4 adoption of compensatory be- of increased HIV transmission, recent, receptive condomless sex The trials did not focus on per- havior such as more sexual partners despite changes in perceived risk (21% vs 12%). ceptions of risk (as participants or more acts of condomless or sexual behavior. For example, In these open-label studies, did not officially know whether sex, then risk compensation is studies have found that adopting changes in behavior did not di- they were receiving PrEP or considered to have occurred. condom use may precede people minish the efficacy of PrEP in a placebo). The first completed There are several observa- having more partners or engaging preventing HIV infection. In- studies found that the combined tions we can draw from previous in more frequent sex, but there creased condomless sex, along drugs tenofovir and emtricitabine research on risk compensation is little evidence that this leads to an with the increased monitoring reduced the risk of HIV infec- andHIV.First,moststudiesrely increased risk of HIV.12 When that PrEP users receive, may, tion by 44% to 75% (modified on behavioral measures (e.g., efficacy is lower, risk compensation however, contribute to the high intention-to-treat analysis), with number of partners or con- may pose a greater problem. The rates of other sexually transmitted higher efficacy among people domless sex), without measur- promotion of male circumcision infections that have been ob- who had detectable drug levels. ing or reporting on attitudinal as a population-level prevention served among PrEP users.23 The studies found no evidence changes or perceptions of strategy, for example, has been However, because PrEP is not risk.11,12 Failing to assess per- controversial because of its of increased condomless sex designed to reduce the risk of fi during the trial period (in fact, ceived risk overlooks a key part moderate ef cacy and lack of 1,2 sexually transmitted infections, of risk compensation theory7,8 protection for female partners.17 condom use increased). A re- increases in sexually transmitted and means that changes in sexual Finally, most research on risk cent systematic review and infections should perhaps be behavior are assumed to be compensation and HIV focuses meta-analysis of 18 trials found considered unintended conse- evidence of risk compensation, on individuals who receive or use that PrEP reduced the risk of HIV quences of PrEP rather than rather than demonstrating that an intervention, rather than infection by 70%, compared with a failure of the HIV-related in- changes in attitudes or percep- considering the effect of in- placebo, as long as participants tervention. How to manage 3 tion precede changes in behavior. terventions on risk perceptions were at least 70% adherent. The sexually transmitted infections as Second, even when attitudes and behavior in the broader review also found no evidence PrEP use increases remains and risk perceptions are mea- community.5 An example of of increased risk-taking behavior a subject of debate. sured, the temporal relationship a compensatory effect occurring in the studies. with behavior may not be clear. beyond those who are the direct To assess risk compensation This relationship is important targets of an intervention is that of related to PrEP, we recommend because some prospective studies HIV treatment optimism: the examining situations outside have found that more frequent belief that it is easier to avoid HIV randomized controlled trials in PREVENTION engagement in condomless sex, (or less serious to contract HIV) as which users know that they are OPTIMISM for example, can precede the a result of effective antiretroviral receiving an active drug that is The effect of PrEP on risk 20 development of optimistic atti- treatment.18,19 People with op- effective in preventing HIV.