Antiretroviral Concentration in Hair as a Measure for Antiretroviral Medication Adherence: A Systematic Review of Global Literature

A Per-Protocol Analysis Using Inverse-Probability-of-Censoring Weights in a Randomized Trial of Initial Protease Inhibitor Versus Nonnucleoside Reverse Transcriptase Inhibitor Regimens in Children

Protocol adherence may influence measured treatment effectiveness in randomized controlled trials. Using data from a multicenter trial (Europe and the Americas, 2002-2009) of children with human immunodeficiency virus type 1 who had been randomized to receive initial protease inhibitor (PI) versus nonnucleoside reverse transcriptase inhibitor (NNRTI) antiretroviral therapy regimens, we generated time-to-event intention-to-treat (ITT) estimates of treatment effectiveness, applied inverse-probability-of-censoring weights to generate per-protocol efficacy estimates, and compared shifts from ITT to per-protocol estimates across and within treatment arms. In ITT analyses, 263 participants experienced 4-year treatment failure probabilities of 41.3% for PIs and 39.5% for NNRTIs (risk difference = 1.8% (95% confidence interval (CI): -10.1, 13.7); hazard ratio = 1.09 (95% CI: 0.74, 1.60)). In per-protocol analyses, failure probabilities were 35.6% for PIs and 29.2% for NNRTIs (risk difference = 6.4% (95% CI: -6.7, 19.4); hazard ratio = 1.30 (95% CI: 0.80, 2.12)). Within-arm shifts in failure probabilities from ITT to per-protocol analyses were 5.7% for PIs and 10.3% for NNRTIs. Protocol nonadherence was nondifferential across arms, suggesting that possibly better NNRTI efficacy may have been masked by differences in within-arm shifts deriving from differential regimen forgiveness, residual confounding, or chance. A per-protocol approach using inverse-probability-of-censoring weights facilitated evaluation of relationships among adherence, efficacy, and forgiveness applicable to pediatric oral antiretroviral regimens.

Measurement Tools and Utility of Hair Analysis for Screening Adherence to Antihypertensive Medication

Poor adherence to the prescribed antihypertensive therapy is an understated public health problem and is one of the main causes of the high prevalence of uncontrolled hypertension in sub-Saharan Africa. Medication adherence is vital for the effectiveness of antihypertensive treatment and is key to ameliorating the clinical outcomes in hypertensive patients. However, it has often been ignored because the current methods used to assess medication adherence are not reliable, limiting their utilization in clinical practice. Therefore, the identification of the most accurate and clinically feasible method for measuring medication adherence is critical for tailoring effective strategies to improve medication adherence and consequently achieve blood pressure goals. This review not only explores various available methods for estimating medication adherence but also proposes therapeutic drug monitoring in hair for the measurement of medication adherence to the antihypertensive medication period.

Hair Zidovudine Concentrations Predict Virologic Outcomes Among People Living with HIV/AIDS in China

BACKGROUND

Hair antiretroviral concentrations are an objective and non-invasive measure of adherence to long-term antiretroviral therapy (ART) and can further predict virologic outcomes among people living with HIV/AIDS (PLWH). Zidovudine, one of the mainstream antiretrovirals in China, has been verified to have high reliability in adherence assessment, especially for its hair concentrations. However, data are limited in its predicting virologic outcomes. Therefore, this study aimed to characterize whether hair zidovudine concentrations can predict virologic suppression among Chinese PLWH compared with hair lamivudine concentrations and two self-reported measures, the overall frequency of adherence behaviors and percentage adherence.

METHODS

This cross-sectional study randomly recruited 564 PLWH currently treated with zidovudine, lamivudine, and other ART agents (efavirenz, nevirapine, or lopinavir/ritonavir) in Guangxi, China. Hair antiretroviral concentrations were determined using the LC-ESI⁺-MS/MS method. Receiver operating characteristic (ROC) curves were used to estimate the optimal classification thresholds of hair concentrations of zidovudine and lamivudine, and the two self-reported measures. Based on those optimal classification thresholds, logistic regression was used to examine whether those four adherence measures can predict virologic suppression (HIV-1 RNA <200 copies/mL).

RESULTS

ROC curves demonstrated good classification performance for association with virologic suppression of zidovudine with the optimal threshold at 58 pg/mg and lamivudine at 255 pg/mg but no self-reported measures. PLWH with hair zidovudine concentrations >58 pg/mg had an adjusted odds ratio (aOR) of 43.191 (95% confidence interval (CI) = 10.171‒183.418, p < 0.001) for virologic suppression. Hair lamivudine concentrations were also associated with virologic suppression (aOR = 10.656, 95% CI = 3.670‒30.943, p < 0.001). However, two self-reported measures did not predict virologic suppression (aORs = 1.157 and 2.488, ps >0.149).

CONCLUSION

Hair zidovudine concentrations can be served as an alternative tool for clinically predicting virologic suppression among PLWH in China.

Simultaneous Determination of 6 Antiretroviral Drugs in Human Hair Using an LC-ESI+-MS/MS Method: Application to Adherence Assessment

BACKGROUND

The determination of antiretroviral drugs in hair is receiving considerable research interest to assess long-term adherence to antiretroviral therapy (ART). Currently in China, lamivudine, zidovudine, nevirapine, efavirenz, ritonavir, and lopinavir are combined as first-line and second-line free therapy regimens and are recommended for people living with HIV (PLWH). Simultaneous determination of the 6 antiretroviral drugs in human hair is important for accurately and widely assessing long-term adherence in Chinese PLWH receiving different ART regimens.

METHODS

Six drugs were extracted from 10-mg hair samples incubated in methanol for 16 hours at 37°C and then analyzed by liquid chromatography with tandem mass spectrometry using a mobile phase of 95% methanol, with an electrospray ionization source in multiple reaction monitoring and positive mode.

RESULTS

The LC-ESI+-MS/MS method exhibited a linear range (R2 > 0.99) within 6-5000, 10-5000, 6-50,000, 12-50,000, 8-5000, and 8-12,500 pg/mg for lamivudine, zidovudine, nevirapine, efavirenz, ritonavir, and lopinavir. For all 6 drugs, the limits of quantification ranged between 6 and 12 pg/mg. The intraday and interday coefficients of variation were within 15%, and the recoveries ranged from 91.1% to 113.7%. Furthermore, the other validation parameters (ie, selectivity, matrix effect, stability, and carryover) met the acceptance criteria stipulated by guidelines of the US Food and Drug Administration and European Medicines Agency. Significant intergroup differences were observed between high-adherence and low-adherence groups, with high intercorrelations in the hair content of the 6 drugs.

CONCLUSIONS

The developed method demonstrated good reliability, to comprehensively and accurately assess adherence in PLWH receiving different ART regimens.

Clinical Value of Emerging Bioanalytical Methods for Drug Measurements: A Scoping Review of Their Applicability for Medication Adherence and Therapeutic Drug Monitoring

INTRODUCTION

Direct quantification of drug concentrations allows for medication adherence monitoring (MAM) and therapeutic drug monitoring (TDM). Multiple less invasive methods have been developed in recent years: dried blood spots (DBS), saliva, and hair analyses.

AIM

To provide an overview of emerging drug quantification methods for MAM and TDM, focusing on the clinical validation of methods in patients prescribed chronic drug therapies.

METHODS

A scoping review was performed using a systematic search in three electronic databases covering the period 2000-2020. Screening and inclusion were performed by two independent reviewers in Rayyan. Data from the articles were aggregated in a REDCap database. The main outcome was clinical validity of methods based on study sample size, means of cross-validation, and method description. Outcomes were reported by matrix, therapeutic area and application (MAM and/or TDM).

RESULTS

A total of 4590 studies were identified and 175 articles were finally included; 57 on DBS, 66 on saliva and 55 on hair analyses. Most reports were in the fields of neurological diseases (37%), infectious diseases (31%), and transplantation (14%). An overview of clinical validation was generated of all measured drugs. A total of 62 drugs assays were applied for MAM and 131 for TDM.

CONCLUSION

MAM and TDM are increasingly possible without traditional invasive blood sampling: the strengths and limitations of DBS, saliva, and hair differ, but all have potential for valid and more convenient drug monitoring. To strengthen the quality and comparability of future evidence, standardisation of the clinical validation of the methods is recommended.

Factors influencing hair lamivudine concentration among people living with HIV in Guangxi, China

BACKGROUND

Hair antiretroviral concentration has served as an innovative and objective measure of antiretroviral adherence. However, some factors (for example, pharmacokinetics and hair characteristics) may contribute to the variability of hair antiretroviral concentration that may threaten the validity and reliability of the hair measure as a biomarker of adherence. This study aimed to examine the potential factors that may influence the measure of hair antiretroviral concentration.

METHODS

Hair samples from a cohort of 372 people living with HIV (PLHIV) receiving lamivudine (300 mg/day) in Guangxi, China. Lamivudine concentration was analysed using liquid chromatography-tandem mass spectrometry. Multivariable linear regression was used to evaluate the associations of hair lamivudine concentration with age, sex, ethnicity, height, weight, body mass index, duration of HIV diagnosis, duration of current regimen, dosing schedule, concomitant antiretroviral medications, frequency of hair washing, hair care products use, hair cosmetic treatment and self-reported adherence.

RESULTS

Multivariable models revealed that frequency of hair washing (β=-0.221, P=0.001), dosing schedule (β=0.141, P=0.036) and self-reported adherence (β=0.160, P=0.002) were associated with hair lamivudine concentration.

CONCLUSIONS

We observed that, among those potential factors, hair lamivudine concentration was influenced by frequency of hair washing and dosing schedule. Therefore, frequency of hair washing and dosing schedule should be considered in future research using hair lamivudine concentration as a measure of lamivudine exposure and biomarker of adherence.

The Value of Assessing Self-Reported and Biological Indicators of Outcomes in Evaluating HIV Programs

PURPOSE OF REVIEW

In this manuscript, we present recent findings concerning concordance and discrepancy between biological measures and self-reports of these three outcomes of HIV programs: HIV status, adherence to antiretroviral medications (ARVs) and use of and adherence to pre-exposure prophylaxis medication (PrEP), and condom use/unprotected sex.

RECENT FINDINGS

Recent studies suggest that three successive rapid HIV tests (for those whose first test in positive) might be reasonably inexpensive and valid biological data to collect to combine with self-reports of HIV status, dried blood spots sufficiently affordable to combine with self-reports of adherence to ARVs and use of or adherence to PrEP, and that the discrepancy between self-reports of condom use and biomarkers of unprotected sex may be relatively small in high-income countries. Additional work on assessment of incorrect condom usage and breakage, standardized self-report measures of condom use, and more private data collection methodologies in low-income settings might reduce the recent observed discrepancies even further. Concordance between self-reports of HIV and biomarkers indicating HIV positive status has varied considerably, with much lower rates in low-income countries, where the stigma of HIV is still very high. Recommendation is for combining self-report data with the results of three successive rapid tests for those testing positive. For adherence, again agreement between self-reports and a variety of more objective and/or biological measures is only moderate. Dried blood spots (DBS) may be sufficiently inexpensive in low-resource settings that this may be the best biological method to combine with self-reports. In publications over the last 8 years, the discrepancy between self-reports of condom use and biomarkers for unprotected sex may be even lower than 20% after controlling for other features of the study, particularly in high-income countries. Our results suggest that more careful assessment of incorrect condom use and breakage as reasons other than intentional misreporting should be investigated more carefully and that more private data collection methods such as audio, computer-assisted self-interviewing (ACASI) might be employed more often in low-resource settings to reduce this discrepancy in those settings further. In addition, further analysis of the discrepancy between self-reports of condom use and biomarkers should be conducted of published studies using the correct calculation methods to be more certain of these findings.

Association of Hair Concentrations of Antiretrovirals with Virologic Outcomes Among People Living with HIV in Guangxi, China

BACKGROUND

Hair concentrations of antiretrovirals are an innovative and non-invasive method for measuring cumulative antiretroviral exposure and assessing long-term antiretroviral adherence. This study aimed to examine hair concentrations of antiretrovirals in relation to virologic outcomes among PLHIV in Guangxi, China.

METHODS

Cross-sectional data of hair concentrations of antiretrovirals and HIV viral load were collected from 215 PLHIV in Guangxi, China. Multivariate logistic regression analyses were used to examine the association of hair concentrations of antiretrovirals with virologic outcomes.

RESULTS

Of the 215 participants, 215, 67, and 163 PLHIV are receiving lamivudine, zidovudine, and efavirenz, respectively. Multivariate analysis revealed that hair concentrations of lamivudine [odds ratio = 16.52, 95% CI 2.51-108.60, p = 0.004] and efavirenz [odds ratio = 14.26, 95% CI 1.18-172.01, p = 0.036], but not zidovudine [odds ratio = 1.77, 95% CI 0.06-56.14, p = 0.747], were the strongest independent predictor of virologic suppression when controlling for sociodemographic and other HIV-related characteristics.

CONCLUSION

Hair concentrations of lamivudine and efavirenz were the strongest independent predictor of virologic suppression among Chinese PLHIV. Hair analysis of antiretrovirals may provide a non-invasive, cost-effective tool that predicts virologic suppression among PLHIV in China.

LC-MS/MS Quantification of Nevirapine and Its Metabolites in Hair for Assessing Long-Term Adherence

The adherence assessment based on the combination of nevirapine (NVP) and its two metabolites (2-hydroxynevirapine and 3-hydroxynevirapine) would more comprehensively and accurately reflect long-term adherence than that of a single prototype. This study aimed to develop a specific, sensitive and selective method for simultaneous detection of the three compounds in hair and explore whether there was consistency among the three compounds in assessing long-term adherence. Furthermore, 75 HIV-positive patients who were taking the NVP drug were randomly recruited and divided into two groups (high-and low-adherence group). All participants self-reported their days of oral drug administration per month and provided their hair strands closest to the scalp at the region of posterior vertex. The concentrations of three compounds in the hair were determined using a developed LC-MS/MS method in multiple reaction monitoring. This method showed good performances in limit of quantification and accuracy with the recoveries from 85 to 115% and in precision with the intra-day and inter-day coefficients of variation within 15% for the three compounds. The population analysis revealed that patients with high-adherence showed significantly higher concentrations than those with low-adherence for all three compounds. There were significantly moderate correlations of nevirapine with 2-hydroxynevirapine and 3-hydroxynevirapin and high correlation between 2-hydroxynevirapine and 3-hydroxynevirapin. The two NVP’s metabolites showed high consistency with NVP in evaluating long-term adherence.

Telephone-Delivered Mindfulness Training to Promote Medication Adherence and Reduce Sexual Risk Behavior Among Persons Living with HIV: An Exploratory Clinical Trial

This study explored whether telephone-delivered mindfulness training (MT) to promote medication adherence and reduce sexual risk behavior was feasible for and acceptable to people living with HIV. Participants (N = 42; 50% female; M age = 47.5 years) were randomized to MT or health coaching (HC). Pre- and post-intervention, and at 3-month follow-up, we assessed adherence to ART, sexual risk behavior, and hypothesized mediators; we also conducted individual interviews to obtain qualitative data. Results showed that 55% of patients assigned to MT completed ≥ 50% of the training calls compared with 86% of HC patients (p < .05). Most patients reported satisfaction with their intervention (MT = 88%, HC = 87%). Patients in MT and HC reported improvements in medication adherence, mindfulness, and sexual risk reduction as well as reductions in anxiety, depressive symptoms, perceived stress, and impulsivity over time; however, no between-groups differences were observed.

Comparing self-reported medication adherence measures with hair antiretroviral concentration among people living with HIV in Guangxi, China

BACKGROUND

Antiretroviral adherence is essential to HIV treatment efficacy. Various self-reported measures are commonly used for assessing antiretroviral adherence. Limited data are available regarding the validity of those self-reported measures in comparison with long-term objective biomarkers of adherence measures such as hair measures.

METHODS

Self-reported adherence (frequency, percentage, and visual analog scale [VAS]) and hair tenofovir concentration were evaluated at a single time point from 268 people living with HIV in China. The responses to each of three self-reported measures were converted into percentage and then dichotomized as "optimal" (100%) vs. "suboptimal" (less than 100%) adherence. Two composite adherence scores (CAS) were created from the three self-reported measures: (1) an overall adherence was the average percentage of the three self-reported measures; (2) responses were termed optimal adherence if participants reporting optimal adherence in all three self-reported measures, while were termed suboptimal adherence. Hair tenofovir concentration was also dichotomized as "optimal" (above the limit of quantitation, 36 pg/mg) vs. "suboptimal" adherence (blow 36 pg/mg). Spearman correlation, kappa statistics, and logistic regression analysis were used to calculate the correlations, agreements, and predictions of self-reported measures with hair measure, respectively.

RESULTS

Overall adherence, but any of the three self-reported adherence, was correlated with hair tenofovir concentration (r = 0.13, p < 0.05). Self-reported optimal adherence in VAS and CAS measures were agreed with and predicted optimal adherence assessed by hair measure (Kappa = 0.107, adjusted OR = 1.88, 95% CI 1.03-3.45; Kappa = 0.109, adjusted OR = 1.80, 95% CI 1.02-3.18; all p < 0.05, respectively).

CONCLUSION

VAS may be a good individual self-reported measure for antiretroviral adherence, and CAS may be a good composite self-reported measure for antiretroviral adherence.