Perception of HIV Risk and Adherence to FEM-PrEP
Perception of HIV Risk and Adherence to FEM-PrEP
Background FEM-PrEP was unable to demonstrate the effectiveness of oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) as pre-exposure prophylaxis for HIV prevention because of low adherence. We hypothesized that one reason for the poor adherence was low perceived HIV risk.
Methods At enrollment and at quarterly follow-up visits, we assessed participants' perceived HIV risk for the subsequent 4 weeks. We used logistic regression to assess factors associated with some (small, moderate, or high) perceived HIV risk. We also used logistic regression with robust variance estimation to assess the association between risk perceptions (none versus some) reported at enrollment and at weeks 12, 24, and 36 and good adherence based on drug concentrations of plasma tenofovir and intracellular tenofovir diphosphate in specimens collected 4 weeks later (at weeks 4, 16, 28, and 40) among 150 randomly selected participants assigned FTC/TDF.
Results Multiple factors were statistically associated with having some perceived risk, including having sex without a condom, having multiple partners, and not knowing if a partner has HIV. We observed a significant association between having some risk perception and good adherence (odds ratio: 2.0; 95% confidence interval: 1.1 to 3.5; P = 0.016).
Conclusions Data suggest that participants are likely knowledgeable about factors that increase their HIV risk. Perceived risk seemed to have influenced some participants' decisions to adhere to the study pill within the context of a placebo-controlled clinical trial. Future research can explore the role of risk perception in the uptake of and adherence to pre-exposure prophylaxis, now that FTC/TDF has been shown efficacious.
HIV prevention options expanded to include antiretroviral-based products after several clinical trials demonstrated that once-daily emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) as pre-exposure prophylaxis (PrEP) reduced the risk of HIV acquisition. However, 2 clinical trials assessing the role of FTC/TDF as PrEP for HIV prevention in women—FEM-PrEP and MTN-003 [Vaginal and Oral Interventions to Control the Epidemic (VOICE)]—did not demonstrate effectiveness of FTC/TDF in their study populations because of low adherence. Low risk perceptions among study participants may have been one of the reasons for the overall poor adherence observed in FEM-PrEP.
Perceived risk is one of several key constructs in many theories of health behavior change, such as the health belief model and the protection motivation theory. Within such frameworks, individuals may be motivated to take action to reduce risk behaviors if they perceive some risk; individuals may also be discouraged to modify their risk behaviors if they perceive no risk. Perception of risk is frequently assessed by asking individuals the question "What is your chance of getting X [ie, the illness] in the next X [ie, timeframe]?" However, defining and measuring perception of risk is complex. Several terms are used interchangeably in public health to describe perceived risk, such as "perceived likelihood," "perceived susceptibility," and "perceived vulnerability." Adding to the complexity, perceived risk may be the outcome of past sexual behavior or it may predict future sexual behavior.
In the field of HIV prevention, a substantial body of literature exists on HIV risk perceptions, including from early in the epidemic. Research has primarily focused on how perceived risk should be defined and measured, on identifying factors associated with perceived risk, and on assessing the associations between perceived risk and engagement in risk behaviors. Findings have varied on the associations between perceived risk and risk-reduction behaviors; however, these variations may be due in part to the interpretation of results from cross-sectional studies and differences in measurement.
In FEM-PrEP, we explored perceptions of HIV risk within a different context than which they are explored in HIV prevention programs that encourage adherence to efficacious risk-reduction methods. We assessed risk perceptions within the context of a placebo-controlled clinical trial, in which counseling focused on encouraging adherence to proven HIV risk-reduction methods (eg, condoms) and to a daily, investigational pill as PrEP for HIV prevention (ie, FTC/TDF). We hypothesized that one reason for the poor adherence observed in FEM-PrEP was low perceived risk of HIV among study participants. Here we describe participants' HIV risk perceptions, factors associated with perceived HIV risk, and the association between HIV risk perceptions and adherence to once-daily, investigational FTC/TDF for HIV prevention.
Abstract and Introduction
Abstract
Background FEM-PrEP was unable to demonstrate the effectiveness of oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) as pre-exposure prophylaxis for HIV prevention because of low adherence. We hypothesized that one reason for the poor adherence was low perceived HIV risk.
Methods At enrollment and at quarterly follow-up visits, we assessed participants' perceived HIV risk for the subsequent 4 weeks. We used logistic regression to assess factors associated with some (small, moderate, or high) perceived HIV risk. We also used logistic regression with robust variance estimation to assess the association between risk perceptions (none versus some) reported at enrollment and at weeks 12, 24, and 36 and good adherence based on drug concentrations of plasma tenofovir and intracellular tenofovir diphosphate in specimens collected 4 weeks later (at weeks 4, 16, 28, and 40) among 150 randomly selected participants assigned FTC/TDF.
Results Multiple factors were statistically associated with having some perceived risk, including having sex without a condom, having multiple partners, and not knowing if a partner has HIV. We observed a significant association between having some risk perception and good adherence (odds ratio: 2.0; 95% confidence interval: 1.1 to 3.5; P = 0.016).
Conclusions Data suggest that participants are likely knowledgeable about factors that increase their HIV risk. Perceived risk seemed to have influenced some participants' decisions to adhere to the study pill within the context of a placebo-controlled clinical trial. Future research can explore the role of risk perception in the uptake of and adherence to pre-exposure prophylaxis, now that FTC/TDF has been shown efficacious.
Introduction
HIV prevention options expanded to include antiretroviral-based products after several clinical trials demonstrated that once-daily emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) as pre-exposure prophylaxis (PrEP) reduced the risk of HIV acquisition. However, 2 clinical trials assessing the role of FTC/TDF as PrEP for HIV prevention in women—FEM-PrEP and MTN-003 [Vaginal and Oral Interventions to Control the Epidemic (VOICE)]—did not demonstrate effectiveness of FTC/TDF in their study populations because of low adherence. Low risk perceptions among study participants may have been one of the reasons for the overall poor adherence observed in FEM-PrEP.
Perceived risk is one of several key constructs in many theories of health behavior change, such as the health belief model and the protection motivation theory. Within such frameworks, individuals may be motivated to take action to reduce risk behaviors if they perceive some risk; individuals may also be discouraged to modify their risk behaviors if they perceive no risk. Perception of risk is frequently assessed by asking individuals the question "What is your chance of getting X [ie, the illness] in the next X [ie, timeframe]?" However, defining and measuring perception of risk is complex. Several terms are used interchangeably in public health to describe perceived risk, such as "perceived likelihood," "perceived susceptibility," and "perceived vulnerability." Adding to the complexity, perceived risk may be the outcome of past sexual behavior or it may predict future sexual behavior.
In the field of HIV prevention, a substantial body of literature exists on HIV risk perceptions, including from early in the epidemic. Research has primarily focused on how perceived risk should be defined and measured, on identifying factors associated with perceived risk, and on assessing the associations between perceived risk and engagement in risk behaviors. Findings have varied on the associations between perceived risk and risk-reduction behaviors; however, these variations may be due in part to the interpretation of results from cross-sectional studies and differences in measurement.
In FEM-PrEP, we explored perceptions of HIV risk within a different context than which they are explored in HIV prevention programs that encourage adherence to efficacious risk-reduction methods. We assessed risk perceptions within the context of a placebo-controlled clinical trial, in which counseling focused on encouraging adherence to proven HIV risk-reduction methods (eg, condoms) and to a daily, investigational pill as PrEP for HIV prevention (ie, FTC/TDF). We hypothesized that one reason for the poor adherence observed in FEM-PrEP was low perceived risk of HIV among study participants. Here we describe participants' HIV risk perceptions, factors associated with perceived HIV risk, and the association between HIV risk perceptions and adherence to once-daily, investigational FTC/TDF for HIV prevention.