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Pretoria, South Africa

Corneli A.,Social and Behavioral Health science | Field S.,Biostatistics | Namey E.,Social and Behavioral Health science | Agot K.,Impact Research and Development Organization | And 4 more authors.
PLoS ONE | Year: 2015

Introduction: Several clinical trials have demonstrated the efficacy of pre-exposure prophylaxis (PrEP) in reducing HIV risk. One concern with introducing PrEP is whether users will engage in riskier sexual behaviors. Methods: We assessed the effect that PrEP may have on sexual risk behaviors by administering a survey to 799 women in Bondo, Kenya, and Pretoria, South Africa. Participants were asked about their sexual behavior intentions twice - once as if they were taking PrEP and once as if they were not taking PrEP - within four risk situations (vignettes). They responded using a 5-point ordinal scale. We used a series of linear mixed effects models with an unstructured residual covariance matrix to estimate the between- and within-subject differences in the mean likelihood of engaging in risky sexual behavior across the PrEP and non-PrEP contexts. We also calculated the total percentage of participants who reported a greater likelihood of engaging in risky sexual behavior if taking PrEP than if not taking PrEP, by vignette. Results: We found statistically significant differences in the mean likelihood of engaging in risky sexual behavior with the between-subject comparison (-0.17, p < 0.01) and with the within-subject comparison (-0.31, p < 0.001). Depending on the vignette, 27% to 40% of participants reported a greater likelihood of engaging in risky sexual behavior if taking PrEP than if not taking PrEP. Conclusions: Our findings indicate that modest increases in risky sexual behavior could occur with PrEP. Although responses from the majority of participants suggest they would not be more likely to engage in risky sexual behavior if they took PrEP, a substantial proportion might. Programs rolling out PrEP should be prepared to assist similar women in making informed choices about reducing their risk of HIV and about their sexual health beyond HIV prevention. © 2015 Corneli et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source


Callahan R.,359 Blackwell Street | Nanda K.,359 Blackwell Street | Kapiga S.,Kilimanjaro Christian Medical Center | Malahleha M.,Setshaba Research Center | And 4 more authors.
Journal of Acquired Immune Deficiency Syndromes | Year: 2015

Pregnancy among study participants remains a challenge for trials of new HIV prevention agents despite promotion and provision of contraception. We evaluated contraceptive use, pregnancy incidence, and study drug adherence by contraceptive method among women enrolled in the FEM-PrEP trial of once-daily oral tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) for HIV prevention. METHODS:: We required women to be using effective non-barrier contraception at enrollment. At each monthly follow-up visit, women were counseled on contraceptive use and tested for pregnancy. TDF-FTC adherence was determined by measuring plasma drug concentrations at 4-week intervals. We used Cox proportional hazards models to assess factors associated with incident pregnancy and multivariate logistic regression to examine the relationship between contraceptive method used at enrollment and TDF-FTC adherence. RESULTS:: More than half of women were not using effective contraception before enrollment. Ninety-eight percent of these women adopted either injectable (55%) or oral (43%) contraceptives. The overall pregnancy rate was 9.6 per 100 woman-years. Among injectable users and new users of combined oral contraceptives (COCs), the rates were 1.6 and 35.1, respectively. New users of injectables had significantly greater odds of adhering to TDF-FTC than new COC users [odds ratio (95% confidence interval): 4.4 (1.7 to 11.6), P = 0.002], existing COC users [3.1 (1.3 to 7.3), P = 0.01], and existing injectable users [2.4 (1.1 to 5.6), P = 0.04]. CONCLUSIONS:: Women using COCs during FEM-PrEP, particularly new adopters, were more likely to become pregnant and less likely to adhere to study product than injectable users. HIV prevention trials should consider requiring long-acting methods, including injectables, for study participation. © 2014 Wolters Kluwer Health, Inc. Source


Corneli A.L.,59 Blackwell Street | Wang M.,FHI | Taylor D.,FHI | Ahmed K.,Setshaba Research Center | And 6 more authors.
Journal of Acquired Immune Deficiency Syndromes | Year: 2014

Background: Several clinical trials have demonstrated the safety and effectiveness of oral tenofovir disoproxil fumarate (TDF), with or without emtricitabine (FTC), as pre-exposure prophylaxis (PrEP) for reducing the risk of HIV acquisition. Adherence to the study product was insufficient to demonstrate the effectiveness of FTC/TDF in 2 PrEP clinical trials conducted among women (FEM-PrEP and the Vaginal and Oral Interventions to Control the Epidemic study), but further analyses of adherence in these studies may inform PrEP demonstration projects and future HIV prevention clinical trials. Methods: We randomly selected a subcohort of 150 participants randomized to FTC/TDF in 3 FEM-PrEP sites (Bondo, Kenya; Bloemfontein, South Africa; and Pretoria, South Africa) to examine adherence levels over time and to assess factors associated with adherence, based on plasma tenofovir and intracellular tenofovir diphosphate drug concentrations in specimens collected at 4-week visit intervals. Results: We observed drug concentrations consistent with good adherence in 28.5% of all visit intervals when drug was available to use, but only 12% of participants achieved good adherence throughout their study participation. In multivariate analysis, the Bloemfontein site [odds ratio (OR):2.43; 95% confidence interval (CI):1.32 to 4.48] and liking the pill color (OR: 2.93; 95% CI: 1.18 to 7.27) were positively associated with good adherence, whereas using oral contraceptive pills at enrollment was negatively associated with good adherence (OR: 0.37; 95% CI: 0.18 to 0.74). Conclusions: Most participants did not regularly adhere to the study product throughout their trial participation, although a smallminority did. Few factors associated with good adherence to the study product were identified in FEM-PrEP. Copyright © 2014 by Lippincott Williams & Wilkins. Source


Corneli A.L.,Social and Behavioral Health science | McKenna K.,Social and Behavioral Health science | Perry B.,Social and Behavioral Health science | Ahmed K.,Setshaba Research Center | And 6 more authors.
Journal of Acquired Immune Deficiency Syndromes | Year: 2015

Background: FEM-PrEP was unable to determine whether once-daily, oral emtricitabine/tenofovir disoproxil fumarate reduces the risk of HIV acquisition among women because of low adherence. Self-reported adherence was high, and pill-count data suggested good adherence. Yet, drug concentrations revealed limited pill use. We conducted a follow-up study with former participants in Bondo, Kenya, and Pretoria, South Africa, to understand factors that had influenced overreporting of adherence and to learn the whereabouts of unused pills. Methods: Qualitative, semistructured interviews were conducted with 88 participants, and quantitative, audio computer-assisted self-interviews were conducted with 224 participants. We used thematic analysis and descriptive statistics to analyze the qualitative and quantitative data, respectively. Results: In audio computer-assisted self-interviews, 31% (n 70) said they had overreported adherence; the main reason was the belief that nonadherence would result in trial termination (69%, n 48). A considerable percentage (35%, n 78) acknowledged discarding unused pills. Few acknowledged giving their pills to someone else (4%, n 10), and even fewer acknowledged giving them to someone with HIV (2%, n 5). Many participants in the semistructured interviews said other participants had counted and removed pills from their bottles to appear adherent. Conclusions: Despite repeated messages that nonadherence would not upset staff, participants acknowledged several perceived negative consequences of reporting nonadherence, which made it difficult to report accurately. Uneasiness continued in the follow-up study, as many said they had not overreported during the trial. Efforts to improve self-reported measures should include identifying alternative methods for creating supportive environments that allow participants to feel comfortable reporting actual adherence. © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source


Corneli A.,Social and Behavioral Health science | Wang M.,Quantitative science | Agot K.,Impact Research and Development Organization | Ahmed K.,Setshaba Research Center | And 3 more authors.
Journal of Acquired Immune Deficiency Syndromes | Year: 2014

Background: FEM-PrEP was unable to demonstrate the effectiveness of oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) as preexposure 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. Copyright © 2014 by Lippincott Williams & Wilkins. Source

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