Study designs for identifying risk compensation behavior among users of biomedical HIV prevention technologies: Balancing methodological rigor and research ethics

Abstract

The growing evidence base for biomedical HIV prevention interventions – such as oral pre-exposure prophylaxis, microbicides, male circumcision, treatment as prevention, and eventually prevention vaccines – has given rise to concerns about the ways in which users of these biomedical products may adjust their HIV risk behaviors based on the perception that they are prevented from infection. Known as risk compensation, this behavioral adjustment draws on the theory of “risk homeostasis,” which has previously been applied to phenomena as diverse as Lyme disease vaccination, insurance mandates, and automobile safety. Little rigorous evidence exists to answer risk compensation concerns in the biomedical HIV prevention literature, in part because the field has not systematically evaluated the study designs available for testing these behaviors. The goals of this Commentary are to explain the origins of risk compensation behavior in risk homeostasis theory, to reframe risk compensation as a testable response to the perception of reduced risk, and to assess the methodological rigor and ethical justification of study designs aiming to isolate risk compensation responses. Although the most rigorous methodological designs for assessing risk compensation behavior may be unavailable due to ethical flaws, several strategies can help investigators identify potential risk compensation behavior during Phase II, Phase III, and Phase IV testing of new technologies. Where concerns arise regarding risk compensation behavior, empirical evidence about the incidence, types, and extent of these behavioral changes can illuminate opportunities to better support the users of new HIV prevention strategies. This Commentary concludes by suggesting a new way to conceptualize risk compensation behavior in the HIV prevention context.

Sex, human rights and AIDS: an analysis of new technologies for HIV prevention in the Brazilian context

“…The limitation is that, for some technologies, the existing information is limited to the experience of specific groups, as is the case of PEPSE, investigated almost exclusively among MSM. Besides that, a great part of the existing analysis was carried out in controlled studies, which limits the extrapolating of the data into "real life" and the routine of health services, for a number of reasons 20 : the interventions performed in this kind of study are not reproducible in large scale; the probability of finding significant differences among the control and intervention groups is small, once that for ethical reasons both groups receive identical standardized interventions, which will not occur in implementation; and the confidence of users in technologies being studied tends to be lower than when they are actually offered in health services. Methodological REV BRAS EPIDEMIOL SEP 2015; 18 SUPPL 1: 89-103 solutions for those limits include 20 : identifying innovative designs for clinical trials, such as the so-called nested-trial strategy that proposes the allocation of the subjects in the arms of the study in the proportion of 2:1, in order to interfere in their perception on the probability of being effectively using the studied drug; in phases II and III trials, including questions to identify participants who believe they are receiving the effective intervention and comparing their behavior with those who believe to be receiving a placebo; carrying out qualitative and mixed-method studies to deepen the knowledge on the risk perception and sexual behaviors; and investing in implementation studies, including analysis of programmatic issues involved in offering the methods.…”

“…In this sense, one of the frequent questions on the matter refers to the possible effects that their implementation may have on sexual behavior. It is feared, above all, the occurrence of the so-called "risk compensation", a notion that postulates that each person accepts living up to a certain level of health risk, estimated subjectively, in exchange of the benefits that a given practice is able to offer them 20 . Given the introduction of a new intervention, people could increasingly adopt nonprotected behavior for perceiving themselves in lower risk 21 .…”

Indivíduos, estruturas e riscos: panorâmica da prevenção primária do HIV em Portugal

“…Além da PrEP, existem outras tecnologias biomé-dicas que podem ser utilizadas como forma de prevenir o HIV, tais como a profilaxia pós-exposição (PEP) por meio da medicação antirretroviral depois da situação de risco, o uso de microbicidas e a circuncisão masculina 40,41 . Atendendo a essas diferentes possibilidades, importa intensificar a sua divulgação e uma utilização adequada em função dos diferentes cenários de potencial contágio.…”

Will Risk Compensation Accompany Pre-Exposure Prophylaxis for HIV?

“…Although risk compensation can be studied, the most rigorous methodological designs are ethically flawed and would be difficult to implement [(36)]. The ideal study design for assessing risk compensation would be a randomized control trial in which one arm was made to believe the intervention would lower their risk and the other was made to believe that it would not change their risk.…”

“…The ideal study design for assessing risk compensation would be a randomized control trial in which one arm was made to believe the intervention would lower their risk and the other was made to believe that it would not change their risk. Under this design, any behavioral differences seen between arms would be attributable to the messages that participants receive, not to the intervention itself [(36)]. However, this design would require deceiving some or all participants and feigning uncertainty about the merits of two conditions in a randomized trial.…”