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

The experience of healthcare workers to HIV pre-exposure prophylaxis (PrEP) implementation in low- and middle-income countries: a systematic review and qualitative meta-synthesis

Background

The effectiveness of pre-exposure prophylaxis has been extensively documented. However, there are substantial gaps between the actual implementation of pre-exposure prophylaxis and the ideal goal, especially in low-and middle-income countries. Healthcare workers play critical roles in the pre-exposure prophylaxis implementation, and they have more multi-level experiences about the barriers of pre-exposure prophylaxis implementation and how to facilitate it. However, the evidence aiming to synthesize their experiences is limited.

Objective

This study aims to aggregate the healthcare workers' experiences of providing pre-exposure prophylaxis in low-and middle-income countries, and find the barriers, facilitators, and recommendations of pre-exposure prophylaxis implementation.

Methods

The ENTREQ (Enhancing transparency in reporting the synthesis of qualitative research) statement was used to guide the design and reporting of this qualitative meta-synthesis. A comprehensive search was conducted from inception of databases to 16th March 2023 in four databases: PubMed, CINAHL Plus with Full Text, Embase, Web of Science. The quality appraisal was conducted using the Joanna Briggs Institute Critical Appraisal Checklist. JBI's meta-aggregation approach was used to guide the data extraction and synthesis, and the JBI ConQual approach was used to evaluate the evidence level of the synthesized findings.

Results

Fourteen articles with good methodological quality were included in this review. A total of 122 findings were extracted and 117 findings with credibility ratings of "unequivocal" or "equivocal" were included in this meta-synthesis. The eligible findings were aggregated into 13 new categories and subsequently developed into 3 synthesized findings: the barriers, facilitators, and recommendations of pre-exposure prophylaxis implementation in low-and middle-income countries. The overall ConQual score of all three synthesized findings was rated as "low."

Conclusion

This review aggregated the experience of health care workers implementing pre-exposure prophylaxis in low-and middle-income countries and we could focus on the following key points to promote the uptake of pre-exposure prophylaxis: improve knowledge about pre-exposure prophylaxis, create a supportive environment, address medication-related barriers, increase the human resources and financial investments, and diversify the providing models.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/. The protocol of this review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO, CRD42023411604).

Self-reported and pill count measures of adherence to oral HIV PrEP among female sex workers living in South-Western Uganda

Background

Female sex workers (FSWs) in Uganda are at high risk of HIV infection. Scaling up oral pre-exposure prophylaxis (PrEP) will reduce HIV incidence if high levels of adherence are maintained. This study evaluates PrEP adherence using clinic-based pill counts and self-reported measures, and factors associated with protective levels of adherence.

Methods

Participants were sex workers who had been taking PrEP for at least 5 months and were attending routine follow-up visits for PrEP care in fishing communities and along the Trans-African Highway. Participants who had a pill count showing at least 85% use since their last clinic visit and those who reported taking their PrEP every day in the last 5 months were categorised as having ‘protective adherence’. Spearman’s correlation and weighted kappa assessed the relationship between pill count and self-reported measures. Bivariate and multivariate logistic regression was used to determine factors associated with protective adherence as measured by pill count.

Results

We recruited 524 FSWs, with a median age of 29 years (IQR 23–35). Participants were recruited from fishing communities and Trans-African Highway towns (n = 297, 56.7%, and n = 227, 43.0%). Nearly three quarters (n = 372, 71.0%) of women were estimated to have protective adherence based on pill count (i.e., a pill count of >85%) and 50.4% by self-report in last 3 months. There was a strong positive association between self-reported measures and pill count measures (rest = 0.6453, 95% CI = 0.5924–0.6927) and a moderate agreement between self-reported measures and pill count measures, κ = 0.544 (95%CI = 0.4869–0.6011, p < 0.001).

Factors associated with protective adherence included being aged 35 years or older (aOR = 2.40, 95% CI = 1.17–4.86), living in a fishing community (aOR = 1.45, 95% CI = 0.62–3.38), and having an STI in last 3 months (aOR = 1.64, 95% CI = 1.07–2.49).

Conclusion

Our findings indicate that PrEP-experienced FSWs attending clinical follow-up visits reported high protective levels of oral pre-exposure prophylaxis, as measured by both pill count and self-reported measures, and a moderate agreement between pill count and self-reported measures.

Usability and effectiveness of adherence monitoring of a mobile app designed to monitor and improve adherence to event-driven and daily HIV pre-exposure prophylaxis among men who have sex with men in Taiwan

Objective

The UPrEPU mobile app is a self-monitoring system to enable men who have sex with men to optimize their pre-exposure prophylaxis adherence for HIV prevention. The app was designed to accommodate a rather complicated event-driven dosing schedule. We aim to evaluate the usability of the UPrEPU app and its effectiveness in improving adherence monitoring.

Methods

From May to October 2020, 35 participants were enrolled for the usability study and followed up for 4 months. Blood samples for the drug concentration in the dried blood spots were obtained once during the second to fourth follow-up visits. The effectiveness of adherence monitoring was analyzed using Cohen's kappa statistic to calculate the concordance between the average number of pills taken and drug concentration in the dried blood spots.

Results

Overall retention was 91.4% (32 participants) at the end of the study. Participants used the app for a mean of 29 days and made 2565 data entries in total, with an average of 76 data entries. The average systematic usability scale score for the app was 71.5, indicating acceptable usability. Slight agreement was reached between the dried blood spots measurement and the number of pills taken and recorded in the app (weighted kappa: 0.21).

Conclusions

Our user-centered UPrEPU app demonstrated that it could accommodate both daily and event-driven dosing schedules for men who have sex with men clients with acceptable usability scores. We confirmed that complex behaviors such as different drug-dosing regimens that are contingent on sexual behaviors could be incorporated into the design of a mobile app.

Adaptation of a Theory-Based Social Networking and Gamified App-Based Intervention to Improve Pre-Exposure Prophylaxis Adherence Among Young Men Who Have Sex With Men in Bangkok, Thailand: Qualitative Study

BACKGROUND

HIV disproportionately affects young Thai men who have sex with men (YMSM). Recent studies report a high incidence and prevalence of HIV among Thai YMSM. The Thai national guidelines have recommended pre-exposure prophylaxis (PrEP) since 2014 for key populations; free PrEP has been piloted since 2019. Smartphone-based mobile health (mHealth) interventions provide an optimal platform for innovative PrEP adherence interventions for Thai YMSM.

OBJECTIVE

This study aims to adapt the P3 (Prepared, Protected, emPowered) app, developed with YMSM and transwomen in the United States to improve PrEP adherence and persistence for YMSM in Thailand. The app aims to provide daily adherence support and addresses gaps in staff available for large-scale PrEP rollout needed to see population-level effects of HIV prevention.

METHODS

We conducted focus group discussions (FGDs) with YMSM and key informant interviews (KIIs) with PrEP care providers in Bangkok, Thailand, to investigate PrEP adherence facilitators and barriers, preferences for functions and features in mHealth apps among YMSM, and how to best adapt the P3 app to the Thai context. We conducted four FGDs with 4-8 participants per group and 15 KIIs.

RESULTS

For FGDs, 23 YMSM participated with a mean age of 20 years (range 18-21), 96% (22/23) enrolled in full-time education, and all owned smartphones. The mean age of KII participants was 40 (range 26-60) years; most were state health service providers, with the majority being counselors (6/15, 40%) and physicians (6/15, 40%). Overall, the facilitators and barriers for PrEP adherence identified were similar to those of MSM and YMSM globally including the United States. Key themes included general recommendations for improving mHealth apps in Thailand, such as presenting reliable information in an appealing format, minimizing privacy risks, and addressing connectivity challenges. Additional themes focused on P3 Thailand adaptations and were related to cultural and stylistic preferences, engagement strategies, and recommendations for new functions. To develop the adapted app, P3 Thailand, these findings were balanced with resource limitations resulting in the prioritization of minor modifications: changes in app esthetics (color scheme, iconography, and imagery) and changes in the presentation of information in two of the app's features. FGDs identified similar PrEP adherence facilitators and barriers to those already addressed within the app.

CONCLUSIONS

The core elements of the P3 app address major PrEP facilitators and barriers for Thai YMSM; however, changes to the app features, including stylistic presentation, were needed to appropriately customize the app to the Thai context. Given the similarities of facilitators and barriers for PrEP adherence globally, adapting existing PrEP mHealth solutions based on input from end users and key informants provides a promising approach. However, partnerships with local app designers and developers can improve the adaptation process and final product.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04413708; http://clinicaltrials.gov/ct2/show/NCT04413708.

Point-of-Care Test for Assessing Tenofovir Adherence: Feasibility and Recommendations from Women in an Oral PrEP Program in Kenya and Their Healthcare Providers

Oral pre-exposure prophylaxis (PrEP) is a highly effective HIV prevention modality when taken as recommended. Women in sub-Saharan Africa may have adherence challenges that remain undisclosed to providers. Real-time measures that identify non-adherence can allow for immediate exploration of adherence challenges, counseling and interventions. We conducted a formative qualitative study in Kenya to explore oral PrEP experiences and reactions to a point-of-care urine test (UT) identifying recent (past 4 days) non-adherence to tenofovir-based PrEP among female PrEP users (25 in-depth interviews; 4 focus groups) and health care provider (10 key informant interviews). Findings indicate that use of the UT would be highly feasible in the context of regular PrEP care, largely acceptable to clients and providers, and could improve adherence. Clients emphasized the need for transparent client-centered strategies in delivering results. This formative study informs the development of tools to implement this point-of-care UT in future interventional studies and clinical settings.

Adherence to oral HIV pre-exposure prophylaxis among female sex workers in Kampala, Uganda

INTRODUCTION

In Kampala Uganda, female sex workers (FSWs) have high HIV prevalence (33%). Oral PrEP is a novel HIV prevention intervention that offers hope to decrease HIV incidence in key populations especially among FSWs. Studies have shown that with poor adherence, oral PrEP has no efficacy, and therefore adherence to PrEP is critical among FSWs to maximize HIV prevention. However, implementation data on adherence to PrEP among FSWs is limited so this study sought to assess adherence to PrEP. Specifically, we sought to 1) determine the level of adherence to PrEP among FSWs, and 2) determine factors associated with PrEP adherence.

METHODS

This cross-sectional study was conducted from November to December 2018; 126 FSWs using PrEP were interviewed using a questionnaire. Adherence was categorically defined as high adherence and low adherence. Logistic regression was done.

RESULTS

Using long-term contraception methods (OR 0.06, 95% CI: 0.04-0.77) and not using condoms with clients (OR 0.07, 95% CI: 0.01-0.42) were negatively associated with high PrEP adherence.

CONCLUSION

Barriers to PrEP adherence need to be addressed for successful PrEP implementation to improve adherence going forward. Service care providers should reinforce positive behaviors such as use of condoms devotedly during PrEP breaks.

Factors associated with self-reported adherence to daily oral pre-exposure prophylaxis among men who have sex with man and transgender women: PrEP Brasil study

Understanding the factors associated with pre-exposure prophylaxis (PrEP) adherence may help in the development of strategies to support, motivate and sustain PrEP use. This study estimated self-reported adherence, described perceived barriers and facilitators and investigated factors associated with adherence to daily oral PrEP among men who have sex with man (MSM) and transgender women after 1 year of PrEP use in Brazil. PrEP Brasil was a prospective, multicentre, open-label demonstration study with MSM and transgender women at high risk for HIV infection. We used logistic regression to evaluate factors associated with complete adherence (not forgetting to take any pills in the past 30 days) at week 48. Of 338 participants included in this analysis, 60% reported complete adherence to daily oral PrEP at week 48. Perceived barriers and facilitators to daily oral PrEP were reported by 38.2% and 98.5%, respectively. The most reported barrier and facilitator were 'I forgot to take my pills' (19.2%) and 'Associate PrEP with a daily activity/task' (58.6%), respectively. In final multivariable analysis, living in Rio de Janeiro (aOR: 0.38; 95% CI: 0.20-0.73), being transgender women (aOR: 0.22; 95% CI: 0.07-0.73), reporting stimulant use (a OR: 0.40; 95% CI: 0.20-0.80) and having any perceived barriers to daily oral PrEP (aOR: 0.12; 95% CI: 0.07-0.23) were associated with decreased odds of complete adherence. Our findings provide information for developing the best practices to promote PrEP adherence in the Brazilian context.

Risk Management on Pre-Exposure Prophylaxis Adherence of Men Who Have Sex with Multiple Men: A Multicenter Prospective Cohort Study

Background

Men who have sex with multiple men (MSMM) belong to a high-risk group for HIV infection, and pre-exposure prophylaxis (PrEP) is an effective measure to prevent the infection. However, few studies on PrEP adherence by MSMM in China exist. We aimed to explore the protective motivation-related factors for PrEP adherence in an HIV-negative MSMM population in Western China and to provide a reference for future risk management and effective prevention strategies.

Methods

Data were collected from a 2-year follow-up cohort study of PrEP in MSM in China. Rogers’ protective motivation theory (PMT) was used to study the PrEP adherence of MSMM, and logistic regression was performed to analyze the influencing factors of PrEP adherence.

Results

A total of 496 MSMM were included in the study: 299 (60.28%) of them in the good adherence group and 197 (39.72%) in the poor adherence group. The threat assessment scores of the good and poor adherence groups were 2.15 ± 0.59 and 2.06 ± 0.47, respectively, and the response assessment scores were 2.81 ± 0.62 and 2.74 ±0.62, respectively. Poor PrEP adherence was associated with on-demand PrEP medication (OR=0.670), students at school (OR=1.837), occasional condom use (OR=1.621), and good HIV knowledge (OR= 0.659). The higher the threat assessment score, the higher the susceptibility; and the lower the response cost, the stronger the protection motivation and the less likely MSMM were to have poor adherence.

Conclusion

On-demand PrEP medication is more conducive to adherence. Preventive management should focus on MSMMs who are students at school, those who occasionally use condoms, and those with poor HIV knowledge. Improving threat perception and susceptibility, and controlling and reducing the response cost can effectively improve PrEP adherence, and the subsequent application of PMT during intervention research can provide a reference for HIV prevention in MSMM.

Approaches to Objectively Measure Antiretroviral Medication Adherence and Drive Adherence Interventions

PURPOSE OF REVIEW

Traditional methods to assess antiretroviral adherence, such as self-report, pill counts, and pharmacy refill data, may be inaccurate in determining actual pill-taking to both antiretroviral therapy (ART) or pre-exposure prophylaxis (PrEP). HIV viral loads serve as surrogates of adherence on ART, but loss of virologic control may occur well after decreases in adherence and viral loads are not relevant to PrEP.

RECENT FINDINGS

Pharmacologic measures of adherence, electronic adherence monitors, and ingestible electronic pills all serve as more objective metrics of adherence, surpassing self-report in predicting outcomes. Pharmacologic metrics can identify either recent adherence or cumulative adherence. Recent dosing measures include antiretroviral levels in plasma or urine, as well as emtricitabine-triphosphate in dried blood spots (DBS) for those on tenofovir-emtricitabine-based therapy. A urine tenofovir test has recently been developed into a point-of-care test for bedside adherence monitoring. Cumulative adherence metrics assess adherence over weeks to months and include measurement of tenofovir-diphosphate in peripheral blood mononuclear cells or DBS, as well as ART levels in hair. Electronic adherence monitors and ingestible electronic pills can track pill bottle openings or medication ingestion, respectively. New and objective approaches in adherence monitoring can be used to detect nonadherence prior to loss of prevention efficacy or virologic control with PrEP or ART, respectively.

What are the situational and behavioral factors associated with condomless anal sex without pre-exposure prophylaxis in MSM?

OBJECTIVE

This study aimed to identify situational and behavioral factors associated with condomless anal sex without on-demand PrEP in the open-label extension (OLE) study of the ANRS-IPERGAY trial.

METHODS

Univariable and multivariable modified Poisson regressions with a generalized estimating equation (GEE) were used. The attributable risk percentage for each explanatory variable and for condomless anal sex without PrEP was calculated.

RESULTS

In the OLE, 19% of anal intercourses were unprotected (i.e. no PrEP or condom). Of these, 85% were attributable to sexual intercourse with main partners and 47% with HIV-negative partners. The following factors were positively associated with condomless anal sex without PrEP: a depressive episode in the previous 12 months [aR (95% CI), P-value: 1.49 (1.02--2.17), 0.039], a higher number of sexual intercourses during the previous 4 weeks [1.01 [1.002--1.02], 0.014], and sexual intercourses under the influence of alcohol [1.45 (1.10--1.92), 0.008]. By contrast, condomless anal sex without PrEP was less frequent during sexual intercourses with known casual, unknown casual and multiple partners [0.20 (0.14--0.30), <0.001; 0.10 (0.05--0.20), <0.001; 0.11 (0.05--0.29), <0.001, respectively], as well as with HIV+ partners with an undetectable viral load and HIV+ partners with a detectable/unknown viral load or unknown serology status [0.57 (0.38--0.86), 0.007; 0.52 (0.32--0.87), 0.012, respectively].

CONCLUSION

Choosing to have condomless anal sex without PrEP depends primarily on the sexual partner's characteristics (level of intimacy, serological status). This reflects a form of rationality in HIV risk management. However, our results raise questions about the true efficacy of managing HIV risk using this approach.

Socioeconomic and Demographic Statuses as Determinants of Adherence to Antiretroviral Treatment in HIV Infected Patients: A Systematic Review of the Literature

BACKGROUND

Socioeconomic and demographic statuses are associated with adherence to the treatment of patients with several chronic diseases. However, there is a controversy regarding their impact on adherence among HIV/AIDS patients. Thus, we performed a systematic review of the evidence regarding the association of socioeconomic and demographic statuses with adherence to antiretroviral therapy (ART) among HIV/AIDS patients.

METHODS

The PubMed database was used to search and identify studies concerning about socioeconomic and demographic statuses and HIV/AIDS patients. Data were collected on the association between adherence to ART and varies determinants factors of socioeconomic (income, education, and employment/occupation) and socio-demographic (sex and age).

FINDINGS

From 393 potentially-relevant articles initially identified, 35 original studies were reviewed in detail, which contained data that were helpful in evaluating the association between socioeconomic/ demographic statuses and adherence to ART among HIV patients. Two original research study has specifically focused on the possible association between socioeconomic status and adherence to ART. Income, level of education, and employment/occupational status were significantly and positively associated with the level of adherence in 7 studies (36.8%), 7 studies (28.0%), and 4 studies (23.5%) respectively out of 19, 25, and 17 studies reviewed. Sex (being male), and age (per year increasing) were significantly and positively associated with the level of adherence in 5 studies (14.3%), and 9 studies (25.7%) respectively out of 35 studies reviewed. However, the determinant of socioeconomic and demographic statuses was not found to be significantly associated with adherence in studies related to income 9(47.4%), education 17(68.0%), employment/ occupational 10(58.8%), sex 27(77.1%), and age 25(71.4%).

CONCLUSION

The majority of the reviewed studies reported that there is no association between socio- demographic and economic variables and adherence to therapy. Whereas, some studies show that age of HIV patients (per year increasing) and sex (being male) were positively associated with adherence to ART. Among socio-economic factors, the available evidence does not provide conclusive support for the existence of a clear association with adherence to ART among HIV patients. There seems to be a positive trend between socioeconomic factors and adherence to ART in some of the reviewed studies.

Performance of HIV pre-exposure prophylaxis indirect adherence measures among men who have sex with men and transgender women: Results from the PrEP Brasil Study

Introduction

Efficacy of daily emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) for PrEP is strongly dependent on the adherence. We examined the concordance between indirect adherence measures and protective drug levels among participants retained through 48 weeks in the PrEP Brasil Study.

Methods

PrEP Brasil was a prospective, multicenter, open-label demonstration project evaluating PrEP provision for men who have sex with men (MSM) and transgender women (TGW) at higher risk for HIV infection within the setting of Brazilian Public Health System. Three indirect adherence measures were obtained at week 48: medication possession ratio (MPR), pill count and self-report (30-days recall). Tenofovir diphosphate (TFV-DP) concentration in Dried Blood Spot (DBS) was measured at week 48. Areas under (AUC) the receiver operating characteristics (ROC) curve were used to evaluate the concordance between achieving protective drug levels (TFV-DP≥700fmol/punch) and the indirect adherence measures. Youden’s index and distance to corner were used to determine the optimal cutoff points for each indirect adherence measure. We calculated sensitivity, specificity, negative (NPV) and positive (PPV) predictive values for the found cutoff points. Finally, Delong test was used to compare AUCs.

Results and discussion

From April, 2014 to July, 2016, 450 participants initiated PrEP, 375(83.3%) were retained through 48 weeks. Of these, 74% (277/375) had TFV-DP ≥700fmol/punch. All adherence measures discriminated between participants with and without protective drug levels (AUC>0.5). High indirect adherence measure was predictive of protective drug levels (PPV>0.8) while low indirect adherence measure was not predictive of lack of protective drug levels (NPV<0.5). No significant differences were found between the adherence methods (p = 0.44).

Conclusions

Low-burden measurements such as MPR and self-report can be used to predict PrEP adherence in a public health context in Brazil for MSM and TGW retained through 48 weeks.

Clinical Trial Number: NCT01989611.

Assessment of Demographic and Socio-Behavioral Factors on Adherence to HIV Pre-Exposure Prophylaxis Using a Markov Modeling Approach

Purpose: Adherence is important for the effectiveness of human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP). The objective of the current work is to assess the impact of multiple demographic and socio-behavioral factors on the adherence to tenofovir-based PrEP among HIV serodiscordant couples in East Africa using Markov mixed-effects modeling approach.

Methods: The Partners Demonstration Project was a prospective, open-label, implementation science-driven study of HIV PrEP among heterosexual HIV serodiscordant couples in Kenya and Uganda. The uninfected partner received oral PrEP according to the “bridge to antiretroviral therapy [ART]” strategy (i.e., until the infected partner had been on ART for ≥6 months). Adherence was monitored electronically; demographic and socio-behavioral data were collected during study visits. Analyzed data reflect 12 months of follow-up per participant. A two-state, first-order, discrete time Markov model was developed with longitudinal adherence data characterized by “dose taking (1)” and “dose missing (0).” Covariate effects were linearly added in the logit domain of transition probability parameters (P01 and P10) in the model. The full covariate model was initially developed, followed by backward elimination process to reduce the model. All significant covariates reported by a prior primary statistical analysis of the same data were included in the full covariate model.

Results: The model included data from 920 participants, who were predominantly male (65%). Significant covariates associated with higher adherence were 25 years or older [odds ratio (OR) for P10, 0.61], female sex (OR for P10, 0.67), participant wanting the relationship with the partner to succeed (OR for P10, 0.79; OR for P01, 1.45), and sex with partner either with 100% or <100% condom use compared to those reported no sex (OR for P10, 0.84; OR for P01, 1.21). Significant covariates associated with lower adherence were partner on ART >6 months (OR for P01, 0.86; OR for P10, 1.34), subject in the study for >6 months (OR for P01, 0.8; OR for P10, 1.25), and problematic alcohol use (OR for P01, 0.63; OR for P10, 1.16).

Conclusion: The developed Markov model provides a mechanistic understanding of relationship between demographic, socio-behavioral covariates, and PrEP adherence, by indicating the pattern of adherence influenced by each factor over time. Such data can be used for further intervention development to promote PrEP adherence.

Comparing Self-Report Pre-Exposure Prophylaxis Adherence Questions to Pharmacologic Measures of Recent and Cumulative Pre-Exposure Prophylaxis Exposure

As pre-exposure prophylaxis (PrEP) effectiveness is strongly linked to adherence, we sought to determine if certain self-report measures could be used to inform objective PrEP adherence. We studied participants from the TAPIR study (a multicenter randomized study of daily text messages to support adherence to PrEP In At-Risk), a 48-week randomized controlled trial of HIV-uninfected men who have sex with men (MSM) randomized to receive text message to support adherence versus standard of care. Self-reported medication adherence was assessed using several validated measures modified for PrEP. Objective PrEP adherence was determined through dried blood spot (DBS) measurement of intracellular tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP). A summary of adherence was estimated using responses to the seven adherence items at weeks 12 and 48 using confirmatory factor analysis. Correlations between self-report questions and drug concentrations were estimated with Pearson's correlations for continuous outcomes and point-biserial correlations for dichotomous outcomes. Receiver operating characteristic (ROC) analyses were conducted to assess the performance of self-report measures in predicting protective or perfect TFV-DP concentrations. Of the 369 participants who completed week 12 or 48 visits, the mean age was 35 (standard deviation 9 years), with 79% White, 12% Black, and 29% Hispanic. Correlations between self-report measures of adherence (both individual items and the adherence factor) and quantifiable FTC-TP and continuous TFV-DP concentrations showed that all self-report measures were significantly associated with these objective measures. Compared to a summary measure of self-reported adherence, the 4-week percent taken question medication recall was the only self-report item similarly or more strongly associated with recent adherence and long-term protective and perfect adherence at weeks 12 and 48. ROC analysis also showed that 4-week percent taken question had a reasonable AUC (0.798 at week 12 and 0.758 at week 48) in predicting protective TFV-DP concentrations. All single-item self-report questions assessing PrEP adherence were significantly associated with biomarker quantification, with the 4-week percent taken question performing best. Therefore, in the absence of drug concentration measurements, a 4-week self-report percent taken question may be a good single-item measure of PrEP adherence.

Associations between perceived barriers and benefits of using HIV pre-exposure prophylaxis and medication adherence among men who have sex with men in Western China

BACKGROUND

To investigate the associations between the perceived barriers and benefits of using HIV pre-exposure prophylaxis medication, including worries about the side effects, disliking taking drugs, perceived burden of taking medication, positive expectations as to the efficacy of the drugs, favourable doctor-patient relationships, and medication adherence among men who have sex with men (MSM) to provide a target for improving medication adherence and reducing HIV infection among MSM.

METHODS

MSM were recruited in western China from April 2013 to October 2014, administered oral tenofovir (TDF) daily and followed up every 12 weeks for 2 years. At each follow-up, the medication rate was calculated based on the self-reported number of missed doses over 2 weeks, and then, the medication adherence was evaluated. The barriers and benefits perceived during medication were obtained by a self-administered questionnaire, and their effects on medication adherence were analysed by linear mixed models.

RESULTS

A total of 411 participants were enrolled in this study, and 1561 follow-up observation points were obtained. The average medication rate was 0.62 ± 0.37, and the medication rate increased with longer follow-up (P < 0.05). The medication rate was higher among MSM who were divorced (compared to those who were unmarried, P < 0.0001). MSM with more positive expectations as to the efficacy of the drugs showed higher rates of medication (P < 0.0001), while those who were more worried about side effects had a lower medication rate (P = 0.0208). In contrast, the dislike of taking the drugs and the burden perceived during medication had no effects on the actual medication rate of taking TDF (P > 0.05).

CONCLUSION

How to obtain and maintain high medication adherence among MSM is the key to the PrEP intervention strategy for effective reduction of HIV infection. For MSM in China, we should deepen their understanding of the effectiveness and safety of PrEP and increase their confidence in PrEP, thereby improving their medication adherence.

TRIAL REGISTRATION

ChiCTR-TRC-13003849 . Registered on 24/06/2013.

An Information-Motivation-Behavioral Skills Model of PrEP Uptake

Despite documented effectiveness of pre-exposure prophylaxis (PrEP), PrEP uptake remains low among at-risk populations. The 2015 CDC report estimates that about 1.2 million people in the US have indications for PrEP. However, only 49,158 or 4% of the targeted population are currently using PrEP. Efforts to optimize uptake of PrEP may be facilitated by the development of a comprehensive theoretical framework which can be used to understand reasons for poor uptake and to develop interventions to maximize PrEP uptake and adherence. This article reviews research on correlates of PrEP uptake and presents findings organized within an Information-Motivation-Behavioral Skills (IMB) model framework. In the context of PrEP uptake, the IMB model asserts that to the extent that at-risk groups are well-informed about PrEP, motivated to act on their knowledge, and have necessary behavioral skills to seek out and initiate PrEP regimen, they will successfully overcome obstacles to initiate and adhere to PrEP. The article proposes an adaptation the IMB model for PrEP uptake, provides empirical support for the adapted IMB model extracted from related research, and discusses its application in PrEP uptake interventions.

Utility of Different Adherence Measures for PrEP: Patterns and Incremental Value

Measuring PrEP adherence remains challenging. In 2009–2010, the International AIDS Vaccine Initiative randomized phase II trial participants to daily tenofovir disoproxil fumarate/emtricitabine or placebo in Uganda and Kenya. Adherence was measured by electronic monitoring (EM), self-report (SR), and drug concentrations in plasma and hair. Each adherence measure was categorised as low, moderate, or high and also considered continuously; the incremental value of combining measures was determined. Forty-five participants were followed over 4 months. Discrimination for EM adherence by area under receiver operating curves (AROC) was poor for SR (0.53) and best for hair (AROC 0.85). When combining hair with plasma or hair with self-report, discrimination was improved (AROC > 0.9). Self-reported adherence was of low utility by itself. Hair level was the single best PK measure to predict EM-assessed adherence; the other measurements had lower discrimination values. Combining short-term (plasma) and long-term (hair) metrics could be useful to assess patterns of drug-taking in the context of PrEP.

Anti-HIV Activity of Ocimum labiatum Extract and Isolated Pheophytin-a

Ocimum plants are traditionally used to manage HIV/AIDS in various African countries. The effects of Ocimum labiatum extract on HIV-1 protease (PR) and reverse transcriptase (RT) is presented here along with characterization of an identified bioactive compound, achieved through ¹H- and 13C-NMR. The extract's effect on HIV-1 replication was assessed by HIV-1 p24 antigen capture. Cytotoxicity of samples was evaluated using tetrazolium dyes and real-time cell electronic sensing (RT-CES). Ocimum labiatum inhibited HIV-1 PR with an IC50 value of 49.8 ± 0.4 μg/mL and presented weak inhibition (21%) against HIV-1 RT. The extract also reduced HIV-1 replication in U1 cells at a non-cytotoxic concentration (25 μg/mL). The CC50 value of the extract in U1 cells was 42.0 ± 0.13 μg/mL. The HIV-1 PR inhibiting fraction was purified using prep-HPLC and yielded a chlorophyll derivative, pheophytin-a (phy-a). Phy-a inhibited HIV-1 PR with an IC50 value of 44.4 ± 1.5 μg/mL (51 ± 1.7 μM). The low cytotoxicity of phy-a in TZM-bl cells was detected by RT-CES and the CC50 value in U1 cells was 51.3 ± 1.0 μg/mL (58.9 ± 1.2 μM). This study provides the first in vitro evidence of anti-HIV activity of O. labiatum and isolated phy-a, supporting further investigation of O. labiatum for lead compounds against HIV-1.

"Since both of us are using antiretrovirals, we have been supportive to each other": facilitators and barriers of pre-exposure prophylaxis use in heterosexual HIV serodiscordant couples in Kisumu, Kenya

Introduction

Since 2015, the World Health Organization recommends pre-exposure prophylaxis (PrEP) for all persons at substantial risk for HIV, including HIV-uninfected partners in serodiscordant relationships in resource-limited settings. As PrEP moves from clinical trials to real-world use, understanding facilitators of and barriers to PrEP initiation and adherence is critical to successful PrEP implementation and rollout.

Methods

We conducted 44 in-depth individual or couple interviews with 63 participants (30 without HIV and 33 with HIV) enrolled in the Partners Demonstration Project in Kisumu, Kenya, between August and September 2014. The semi-structured interviews discussed the following: 1) perceived advantages and disadvantages of antiretroviral therapy (ART)/PrEP; 2) reasons for accepting or declining ART/PrEP and 3) influence of prevention of transmission to partner or infant on ART/PrEP use. Transcripts from the interviews were iteratively analyzed using inductive content analysis.

Results

Our study identified three key factors that may facilitate initiation of PrEP in this population. First, participants using PrEP felt reduced stress and increased trust in their HIV serodiscordant relationships. Second, greater community-wide knowledge of PrEP was thought to likely increase PrEP acceptance. Third, greater education and counselling by providers on PrEP use was also considered to likely increase the adoption of PrEP. We also identified three key barriers to initiation of and adherence to PrEP. First, most participants who declined PrEP expressed doubts about the relative additional effectiveness of PrEP in combination with other prevention tools. Second, perceived stigma related to PrEP use was an important barrier to PrEP initiation. Third, many struggled with overcoming perceived side effects or logistical challenges of taking daily PrEP, particularly when they themselves were not ill.

Conclusions

Leveraging the facilitators and overcoming barriers to PrEP uptake may enhance the successful rollout of PrEP among HIV serodiscordant couples in Kenya and other areas in sub-Saharan Africa, thereby reducing sexual transmission of HIV. Further research focused on how best to provide counselling on combination HIV prevention tools in the context of PrEP use is a crucial next step to delivering PrEP.

Current concepts for PrEP adherence in the PrEP revolution: from clinical trials to routine practice

PURPOSE OF REVIEW

The review describes the current understanding of adherence to oral preexposure prophylaxis (PrEP), methods for adherence measurement, approaches to supporting PrEP adherence, and guidance for defining PrEP adherence goals within the larger context of HIV prevention.

RECENT FINDINGS

PrEP adherence has generally been higher in recent trials, open-label extensions, and demonstration projects compared with the initial clinical trials; potential explanations include known PrEP efficacy and different motivations to take PrEP. Recent studies have explored adherence monitoring through electronic pill containers, short message service (SMS), and drug concentrations in hair and dried blood spots. The few PrEP adherence interventions developed to date include combinations of enhanced counseling, feedback of objective adherence measurement, and SMS. Conceptualization of PrEP adherence is evolving. The goal is not 100% adherence indefinitely, as it was in clinical trials. PrEP adherence should be defined with respect to HIV exposure, which varies over time by sexual behavior and use of other prevention strategies.

SUMMARY

PrEP adherence beyond clinical trials has generally been high enough to achieve reliable HIV prevention. Future efforts to measure and support PrEP adherence should focus on the context of risk for HIV acquisition, accounting for dynamic behaviors and choices among HIV prevention options.

Comparison of subjective and objective adherence measures for preexposure prophylaxis against HIV infection among serodiscordant couples in East Africa

BACKGROUND

Preexposure prophylaxis (PrEP) efficacy is highly dependent on adherence. Yet, it is unclear which adherence measures perform best for PrEP.

METHODS

We compared three types of self-reported adherence questions (rating of ability to adhere, frequency of doses taken, percentage of doses taken) and three forms of objective adherence measurement [unannounced pill counts (UPC), electronic monitoring, plasma tenofovir levels] using data from an ancillary adherence study within a clinical trial of PrEP among East African serodiscordant couples (Partners PrEP Study). Monthly measures were assessed for the first 6 months of follow-up.

RESULTS

One thousand, one hundred and forty-seven participants contributed 6048 person-months of data to this analysis. Median adherence was high: self-reported rating (90%), self-reported frequency (93%), and self-reported percentage (97%); UPC (99%); and electronic monitoring (97%). Prevalence of steady-state daily dosing (SSDD; ≥40 ng/ml) was 74% in a random subset of tenofovir samples obtained from 365 participants. Discrimination of SSDD versus less than SSDD levels was poor for self-reported rating [area under the receiver-operating curve (AROC) 0.54], self-reported frequency (AROC 0.52), self-reported percentage (AROC 0.56) and UPC (AROC 0.58), but moderate for electronic monitoring (AROC 0.70). Correlation was moderate among self-reported measures, adherence (0.61-0.66), but low for these self-reported measures compared with UPC (0.32-0.36) and with electronic monitoring (0.22-0.28).

CONCLUSION

Electronic monitoring was the only adherence measure with meaningful ability to discriminate between SSDD and less than SSDD plasma tenofovir levels. Correlation between subjective and objective measures was poor. Future research should explore novel approaches to adherence measurement as PrEP moves into demonstration projects and programmatic implementation.

Knowledge, Attitudes, and Experiences of HIV Pre-Exposure Prophylaxis (PrEP) Trial Participants in Botswana

Recent clinical trials have shown that a daily dose of oral TDF/FTC pre-exposure prophylaxis (PrEP) is effective in reducing human immunodeficiency (HIV) risk. Understanding trial participants’ perspectives about retention and PrEP adherence is critical to inform future PrEP trials and the scale-up and implementation of PrEP programs. We analyzed 53 in-depth interviews conducted in April 2010 with participants in the TDF2 study, a Phase 3, randomized, double-blind, placebo-controlled clinical trial of daily oral TDF/FTC with heterosexual men and women in Francistown and Gaborone, Botswana. We examined participants’ knowledge, attitudes, and experiences of the trial, identified facilitators and barriers to enrollment and retention, and compared participant responses by study site, sex, and study drug adherence. Our findings point to several factors to consider for participant retention and adherence in PrEP trials and programs, including conducting pre-enrollment education and myth reduction counseling, providing accurate estimates of participant obligations and side effect symptoms, ensuring participant understanding of the effects of non-adherence, gauging personal commitment and interest in study outcomes, and developing a strong external social support network for participants.