Dataset Information

Factors Associated with Adherence and Concordance Between Measurement Strategies in an HIV Daily Oral Tenofovir/Emtricitibine as Pre-exposure Prophylaxis (Prep) Clinical Trial, Botswana, 2007-2010.

ABSTRACT: This study examined study product adherence and its determinants in the Botswana oral pre-exposure prophylaxis efficacy trial. Among the 1,219 participants, the mean adherence by pill count and 3-day self-report was 94 % for each. In multivariable models, pill count adherence was significantly associated with adverse events (nausea, dizziness, vomiting) (RR 0.98 95 % CI 0.98-1.00; p = 0.03) and side effect concerns (RR 0.98 95 % CI 0.96-0.99; p = 0.01). Self-reported adherence was significantly associated with having an HIV-positive partner (RR 1.02 95 % CI 1.00-1.04; p = 0.02) and Francistown residence (RR 0.98 95 % CI 0.96, 0.99; p = 0.0001). Detectable drug concentrations showed modest associations with self-report and pill count adherence, and drug levels were higher among those self-reporting 100 % adherence than those reporting <100 %. Most common adherence barriers involved refill delays and other logistic challenges; cellphone alarm reminder use was the most common facilitator.

SUBMITTER: Kebaabetswe PM

PROVIDER: S-EPMC4586059 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature

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Factors Associated with Adherence and Concordance Between Measurement Strategies in an HIV Daily Oral Tenofovir/Emtricitibine as Pre-exposure Prophylaxis (Prep) Clinical Trial, Botswana, 2007-2010.

Kebaabetswe Poloko M PM Stirratt Michael J MJ McLellan-Lemal Eleanor E Henderson Faith L FL Gray Simone C SC Rose Charles E CE Williams Tiffany T Paxton Lynn A LA

AIDS and behavior 20150501 5

This study examined study product adherence and its determinants in the Botswana oral pre-exposure prophylaxis efficacy trial. Among the 1,219 participants, the mean adherence by pill count and 3-day self-report was 94 % for each. In multivariable models, pill count adherence was significantly associated with adverse events (nausea, dizziness, vomiting) (RR 0.98 95 % CI 0.98-1.00; p = 0.03) and side effect concerns (RR 0.98 95 % CI 0.96-0.99; p = 0.01). Self-reported adherence was significantly ...[more]

PMID: 25186785

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Project description:BackgroundPre-Exposure Prophylaxis (PrEP) has demonstrated efficacy in the reduction of sexually transmitted HIV infections. The prolonged use of tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) co-formulation (TDF/FTC), however, may result in augmented risk of renal toxicity. We aimed to evaluate changes in the estimated Glomerular Filtration Rate (eGFR) in a real-world population setting of participants enrolled in PrEP Brazil, a 48-week prospective, open-label, demonstration study to assess the feasibility of daily oral TDF/FTC used by men who have sex with men and transgender women at high-risk of HIV infection, all over 18 years old.MethodsKidney function was assessed by serial measurement of serum creatinine and eGFR with the Modification of Diet in Renal Disease Study (MDRD) formula on weeks 4, 12, 24, 36 and 48. Adherence to PrEP was assessed by dosing TDF concentration in dried blood spots at weeks 4 and 48, measured by liquid chromatography-mass spectrometry or mass spectrometry.ResultsOf 392 participants completing the 48-week follow-up protocol with TDF blood detectable levels and eGFR measures, 43.1% were young adults, of Caucasian ethnic background (57.9%), with BMI below 30 kg/m2, without arterial hypertension. At screening, median eGFR was 93.0 mL/min/1.73 m2. At week 4 follow-up, 90 (23% of the study population) participants presented reductions in eGFR greater than 10 mL/min/1.73 m2 as compared to baseline eGFR, some as large as 59 mL/min/1.73 m2, but with no clinical outcomes (adverse events and renal adverse events) severe enough to demand TDF/FTC discontinuation. A negative relationship was observed between TDF blood levels and eGFR at weeks 4 (r = - 0.005; p < 0.01) and 48 (r = - 0.006; p < 0.01).ConclusionsThese results suggest that the renal function profile in individuals on TDF/FTC may be assessed on week 4 and then only annually, allowing a more flexible medical follow-up in primary care centers.

Project description:BackgroundPre-exposure prophylaxis (PrEP) trials using tenofovir-based regimens have demonstrated that high levels of adherence are required to evaluate efficacy; the incorporation of objective biomarkers of adherence in trial design has been essential to interpretation, given the inaccuracy of self-report. Antiretroviral measurements in scalp hair have been useful as a marker of long-term exposure in the HIV treatment setting, and hair samples are relatively easy and inexpensive to collect, transport, and store for analysis. To evaluate the relationship between dose and tenofovir concentrations in hair, we examined the dose proportionality of tenofovir in hair in healthy, HIV-uninfected adults.MethodsA phase I, crossover pharmacokinetic study was performed in 24 HIV-negative adults receiving directly-observed oral tenofovir tablets administered 2, 4, and 7 doses/week for 6 weeks, with a ≥3-week break between periods. Small samples of hair were collected after each six-week period and analyzed for tenofovir concentrations. Geometric-mean-ratios compared levels between each pair of dosing conditions. Intensive plasma pharmacokinetic studies were performed during the daily-dosing period to calculate areas-under-the-time-concentration curves (AUCs).ResultsOver 90% of doses were observed per protocol. Median tenofovir concentrations in hair increased monotonically with dose. A log-linear relationship was seen between dose and hair levels, with an estimated 76% (95% CI 60-93%) increase in hair level per 2-fold dose increase. Tenofovir plasma AUCs modestly predicted drug concentrations in hair.ConclusionsThis study found a strong linear relationship between frequency of dosing and tenofovir levels in scalp hair. The analysis of quantitative drug levels in hair has the potential to improve adherence measurement in the PrEP field and may be helpful in determining exposure thresholds for protection and explaining failures in PrEP trials. Hair measures for adherence monitoring may also facilitate adherence measurement in real-world settings and merit further investigation in upcoming PrEP implementation studies and programs.Trial registrationClinicalTrials.gov NCT00903084.

Project description:BackgroundEfficacy of oral pre-exposure prophylaxis (PrEP) in prevention of HIV acquisition has been evaluated using a daily regimen. However, adherence to long term daily medication is rarely perfect. Intermittent regimen may be a feasible alternative. Preclinical studies have demonstrated effectiveness of intermittent PrEP in SHIV prevention among animals. However, little is known about intermittent PrEP regimens.DesignSeventy two HIV-uninfected volunteers in HIV serodiscordant couple relationships in Uganda were randomly assigned to receive daily oral Tenofovir/Emtricitabine (TDF/FTC-Truvada) or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day) oral TDF/FTC or placebo in a 2:1:2:1 ratio. Volunteers and study staff were blinded to drug assignment, but not to regimen assignment.MethodsVolunteers were followed for 4 months after randomization, with monthly clinical and laboratory safety assessments and comprehensive HIV risk reduction services. Adherence was monitored using medication event monitoring system (MEMS) and self-report. Sexual activity data were collected via daily short text message (SMS) and self-report. HIV-specific immune responses were assessed by IFN-γ ELISPOT.ResultsBoth daily and intermittent oral TDF/FTC regimens were well tolerated. Median MEMS adherence rates were 98% (IQR: 93-100) for daily PrEP regimen, 91% (IQR: 73-97) for fixed intermittent dosing and 45% (IQR: 20-63) for post-coital dosing. SMS response rate was 74%, but increased to 80% after excluding server outages; results may have been affected by the novelty of this measure. The majority of volunteers expressed willingness with no particular preference for either regimen.ConclusionsBoth daily and intermittent oral PrEP dosing regimens were safe. Adherence was high for daily and fixed intermittent dosing; post-coital dosing was associated with poor adherence. Fixed intermittent PrEP regimens may be feasible especially if a minimum effective drug concentration correlating with HIV prevention can be achieved with this dosing.RegistrationClinicaltrials.gov number NCT00931346.

Project description:BackgroundOptimising HIV pre-exposure prophylaxis (PrEP) provision requires insight into preferences of PrEP regimens and PrEP discontinuation. We assessed regimen switching and discontinuation and their determinants among men who have sex with men (MSM) participating in the Amsterdam PrEP demonstration project.MethodsBetween 3-August-2015 and 31-May-2016, we enrolled MSM (n = 374) and TGP (n = 2) in a prospective, longitudinal study. Participants could choose between daily or event-driven PrEP regimens at enrolment and every 3 months. We assessed transition intensities (TI) and determinants of switching (i) between regimens, and (ii) from either regimen to discontinuing PrEP using a multi-state Markov model. PrEP discontinuation was defined as formally stopping study participation or having no study visit for ≥6 months.FindingsOf 367 analysed participants, 73·3% chose daily and 26·7% event-driven PrEP at enrolment. Median follow-up was 3·1 years (IQR 2·9-3·2). 121 participants switched their PrEP regimen at least once (cumulative probability 34·2%, 95% CI 29·4-39·6), with 90 switches from event-driven to daily PrEP (TI 0·35/PY, 95% CI 0·29-0·44) and 113 switches from daily to event-driven PrEP (TI 0·16/PY, 95% CI 0·13-0·20). Switching from event-driven to daily PrEP was associated with younger age, not reporting sex with HIV-positive partners, chemsex, and sexual compulsivity. Switching from daily to event-driven PrEP were associated with younger age and lower sexual satisfaction. 67 participants discontinued PrEP (cumulative probability 17·7%, 95% CI 14·1-22·2), with no difference between regimens: event-driven (n = 23, TI 0·08/PY, 95% CI 0·05-0·13) and daily PrEP (n = 44, TI 0·06/PY, 95% CI 0·04-0·08). Discontinuing daily PrEP was associated with younger age, fewer casual partners, and higher number of condomless anal sex acts with casual partners.InterpretationSwitching between PrEP regimens was common, while going from event-driven to daily PrEP use was associated with certain sexual-related determinants (i.e. chemsex, sexual compulsivity, no known HIV-positive partners). PrEP discontinuation rates were low and independent of regimens. PrEP care should consider the reasons for choice and switch of regimen and involve education on safely switching or discontinuing PrEP, especially among younger MSM.FundingZonMw, H-TEAM, RIVM, GGD research funds, Aidsfonds, Amsterdam Diner Foundation, Gilead Sciences, Gilead Sciences Europe Ltd, Janssen Pharmaceuticals, MAC AIDS Fund, ViiV Healthcare.

Project description:IntroductionHIV incidence remains high among African adolescent girls and young women (AGYW), who would benefit from pre-exposure prophylaxis (PrEP). Strategies to increase PrEP adherence and persistence need to be evaluated in African AGY, including incentives conditional on high adherence.MethodsThe 3Ps for Prevention Study was a 12-month prospective cohort of 200 women ages 16 to 25 initiating PrEP in South Africa from 2017 to 2018. Participants received retrospective feedback about drug levels at Months 1, 2 and 3; half was randomized to receive a 200 Rand shopping voucher ($13 US) at Months 2, 3 and 4, conditioned on high intracellular tenofovir diphosphate (TFV-DP) levels in dried blood spots (≥500 fmol/punch at Month 1, ≥700 fmol/punch at Months 2 and 3). The primary analysis was intention-to-treat, comparing the proportion with high PrEP adherence (≥700 fmol/punch) at Month 3 by randomized group, based on 100% efficacy among men who have sex with men.ResultsMedian age of the 200 women was 19 years (interquartile range [IQR] 17, 21); 86% had a primary sexual partner. At Month 3, the mean TFV-DP level was 822 fmol/punch (SD 522) in the incentive group and 689 fmol/punch (SD 546) in the control group (p = 0.11). Forty-five (56%) of 85 women in the incentive group and 35 (41%) of 85 women in the control group had TFV-DP levels ≥700 fmol/punch (RR 1.35; 95% CI 0.98, 1.86; p = 0.067), which declined to 8% and 5% in the incentive and control groups at Month 12 (no significant difference by arm). 44% refilled PrEP without gaps, 14% had a gap of ≥3 weeks in coverage subsequently restarted PrEP and 54% accepted at the final dispensing visit at Month 9. No new HIV infections were observed after PrEP initiation.ConclusionsAmong South African AGYW initiating PrEP, drug levels indicated high PrEP adherence in almost half of women at Month 3, with a non-statistically significant higher proportion with high adherence among those in the incentive group. Over half persisted with the 12-month PrEP programme although high adherence declined after Month 3. Strategies to support PrEP adherence and persistence and longer-acting PrEP formulations are needed.

Project description:IntroductionHIV pre-exposure prophylaxis (PrEP), in which people take HIV medication to prevent HIV acquisition, underpins global HIV transmission elimination strategies. Effective prevention needs people to adhere to PrEP and remain in care during periods of risk, but this is difficult to achieve. We undertook a process evaluation of Scotland's PrEP programme to explore barriers and facilitators to PrEP adherence and retention in care and to systematically develop evidence-based, theoretically-informed recommendations to address them.MethodsWe conducted semi-structured interviews and focus groups (09/2018-07/2019) with patients who identified as gay or bisexual men and were either using PrEP, had declined the offer of PrEP, had stopped PrEP, or had been assessed as ineligible for PrEP (n = 39 of whom n = 5 (13%) identified as trans, median age 31 years and interquartile range 14 years), healthcare professionals involved in PrEP provision (n = 54 including specialist sexual health doctors and nurses of various grades, PrEP prescribing general practitioners, health promotion officers, midwifes, and a PrEP clinical secretary), and clients (n = 9) and staff (n = 15) of non-governmental organisations with an HIV prevention remit across Scotland. We used thematic analysis to map key barriers and facilitators to priority areas that could enhance adherence and retention in care. We used implementation science analytic tools (Theoretical Domains Framework, Intervention Functions, Behaviour Change Technique Taxonomy, APEASE criteria) and expert opinion to systematically generate recommendations.ResultsBarriers included perceived complexity of on-demand dosing, tendency for users to stop PrEP before seeking professional support, troublesome side-effects, limited flexibility in the settings/timings/nature of review appointments, PrEP-related stigma and emerging stigmas around not using PrEP. Facilitators included flexible appointment scheduling, reminders, and processes to follow up non-attenders. Examples of the 25 recommendations include: emphasising benefits of PrEP reviews and providing appointments flexibly within individualised PrEP care; using clinic systems to remind/recall PrEP users; supporting PrEP conversations among sexual partners; clear on-demand dosing guidance; encouraging good PrEP citizenship; detailed discussion on managing side-effects and care/coping planning activities.ConclusionsPrEP adherence and retention in care is challenging, reducing the effectiveness of PrEP at individual and population levels. We identify and provide solutions to where and how collaborative interventions across public health, clinical, and community practice could address these challenges.

Dataset Information

Factors Associated with Adherence and Concordance Between Measurement Strategies in an HIV Daily Oral Tenofovir/Emtricitibine as Pre-exposure Prophylaxis (Prep) Clinical Trial, Botswana, 2007-2010.

Publications

Factors Associated with Adherence and Concordance Between Measurement Strategies in an HIV Daily Oral Tenofovir/Emtricitibine as Pre-exposure Prophylaxis (Prep) Clinical Trial, Botswana, 2007-2010.

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