Measuring adherence to antiretroviral treatment: the role of pharmacy records of drug withdrawals

Discrepancies between self-reported medication in adherence and indirect measurement adherence among patients undergoing antiretroviral therapy: a systematic review

BACKGROUND

Given the critical importance of medication adherence in HIV/AIDS treatment, this study aims to compare medication adherence measured by self-report (SR) and indirect measurement among antiretroviral therapy (ART) patients, exploring the differences of adherence results measured by different tools.

METHODS

We systematically searched PubMed, Embase, and the Cochrane Library to identify all relevant literature published up to November 22, 2023, without language restrictions, reporting adherence to ART measured by both SR and indirect measurement methods, while also analyzing individual and group adherence separately. Discrepancies between SR and indirect measurement results were assessed using the Mann-Whitney U test or Wilcoxon signed-rank test, with correlations evaluated using the Pearson correlation coefficient. Following one-to-one comparisons, meta-epidemiological one-step analysis was conducted, and network meta-analysis techniques were applied to compare results obtained through specific adherence assessment tools reported in the identified articles.

RESULTS

The analysis encompassed 65 original studies involving 13,667 HIV/AIDS patients, leading to 112 one-to-one comparisons between SR and indirect measurement tools. Statistically significant differences were observed between SR and indirect measurement tools regarding both individual and group adherence (P < 0.05), with Pearson correlation coefficients of 0.843 for individual adherence and 0.684 for group adherence. During meta-epidemiological one-step analysis, SR-measured adherence was determined to be 3.94% (95% CI: -4.48-13.44%) higher for individual adherence and 16.14% (95% CI: 0.81-18.84%) higher for group adherence compared to indirectly measured results. Subgroup analysis indicated that factors such as the year of reporting and geographic region appeared to influence the discrepancies between SR and indirect measurements. Furthermore, network meta-analysis revealed that for both individual and group adherence, the results obtained from most SR and indirect measurement tools were higher than those from electronic monitoring devices, with some demonstrating statistical significance (P < 0.05).

CONCLUSIONS

The findings underscored the complexity of accurately measuring medication adherence among ART patients. Significant variability was observed across studies, with self-report methods showing a significant tendency towards overestimation. Year of reporting, geographic region, and adherence measurement tools appeared to influence the differences between SR and indirect measurements. Future research should focus on developing and validating integrated adherence measurements that can combine SR data with indirect measures to achieve a more comprehensive understanding of adherence behaviors.

Long-term virological effectiveness with darunavir/ritonavir-based salvage therapy in people living with HIV/AIDS from São Paulo, Brazil

Even though darunavir/ritonavir (DRV/r) has high potency and a greater genetic barrier, there are few studies on the long-term effectiveness of DRV/r-based salvage therapy in people living with HIV (PLWH) in low and middle-income countries. This retrospective cohort study, from São Paulo, Brazil, included ART-experienced PLWH aged ≥18 years with virological failure (VF) who had started DRV/r plus an optimized background regimen (OBR) between 2008 and 2012. The proportion of patients with viral load (VL) <50 copies/mL, the improved mean CD4+ T cell count and the factors associated with VF during the 144-week follow-up were assessed. The study included 173 patients with the following characteristics [median (interquartile range)]: age 48 (42 -53) years; CD4+ T cell count, 229 (89 -376) cells/mm3; VL, 4.26 (3.70 -4.74) log10; 6 (4 -7) previous regimens; and 100 (38 -156) months of VF. After 144 weeks, 129 (75%) patients had VL< 50 copies/mL and a mean increase in the CD4+ T cell count of 190 cells/mm3. VL>100,000 copies/mL and poor adherence were associated with VF. DRV/r plus an OBR showed high long-term virological suppression and immunological recovery. VL>100,000 copies/mL and poor adherence were associated with VF at 144 weeks.

Recommended method for health services to determine adherence to antiretroviral therapy: a comparison of three models

The medication possession ratio (MPR) method is commonly used for the determination of antiretroviral medication adherence. However, different ways of calculating MPR and methodological issues hinder the interpretation of the results and the reproducibility of the method. Thus, this study used three different models of MPR calculation and aimed to identify the one that best represents the situation of patient adherence. The results show that there was a statistically significant difference between the adherence rates determined by the three models, which indicates the need to specify the parameters used for calculation in the MPR method. However, the models individually were found to be related to viral suppression, but none of them had a greater effect than the other in this regard. The model that used residual medication (RM) and a fixed period of analysis allowed for a more precise identification of the number of doses that the patient used when compared to the others. Health services should avoid the application of the model using a variable analysis period. This study found that RM and the period of analysis considered are the main influencing factors in the accuracy of adherence results when the MPR method is used.

Hepatitis B viremia in HIV-coinfected individuals under antiretroviral therapy

BACKGROUND

Antiretroviral therapy (ART) has decreased AIDS incidence and mortality, rendering comorbidities, such as hepatitis B more relevant for people living with human immunodeficiency virus (HIV). Since antiretroviral drugs may also inhibit hepatitis B virus (HBV) replication, analyzing the impact of ART on management of hepatitis B in this population is important.

OBJECTIVE

To assess HBV viremia among HIV/HBV coinfected individuals on ART and its associated factors.

METHOD

For this cross-sectional study, HIV/HBV-coinfected individuals, aged over 18 years, who were on ART for over six months and receiving care at an outpatient clinic in São Paulo were recruited. Sociodemographic characteristics, information about viral exposure, clinical and laboratory data, including evaluation of liver fibrosis were obtained. Plasma HBV DNA was measured by polymerase chain reaction. Viral genome sequencing was conducted for genotyping and identification of drug resistance-conferring mutations if viral load exceeded 900 IU/mL.

RESULTS

Out of 2,946 patients who attended the clinic in 2015, 83 were eligible and 56 evaluated. Plasma HBV DNA was detected in 16 (28.6%) (95% CI: 18.0-41.3%), all on lamivudine and tenofovir treatment. HBV DNA detection was associated with lower education (p = 0.015), higher international normalized ratios (p = 0.045), history of an AIDS-defining illness [OR: 3.43 (95% CI: 1.10-11.50)], and HBeAg detection [OR: 6.60 (95% CI: 1.84-23.6)]. In contrast, a last CD4+ count above 500 cells/mm3 in the year prior to inclusion [OR: 0.18 (95% CI: 0.04-0.71)] and detection of anti-HBe [OR: 0.21 (95% CI: 0.04-0.99)] were negatively associated. Patients with HBV DNA above 900 IU/mL were infected with subgenotypes A1 (n = 3) and D2 (n = 1), and exhibited viral mutations associated with total resistance to lamivudine and partial resistance to entecavir.

CONCLUSIONS

Despite being on ART, a significant proportion of HIV/HBV-coinfected individuals present HBV viremia. Characterization of factors that are associated with this finding may help professionals provide better management to these patients.

Adherence to antiretroviral therapy for HIV/AIDS in Latin America and the Caribbean: Systematic review and meta-analysis

INTRODUCTION

Optimal adherence to antiretroviral therapy is closely related with suppression of the HIV viral load in plasma, slowing disease progression and decreasing HIV transmission rates. Despite its importance, the estimated proportion of people living with HIV in Latin America and the Caribbean with optimal adherence has not yet been reported in a meta-analysis. Moreover, little is known of the factors leading to poor adherence which may be setting-specific. We present a pooled estimate of adherence to antiretroviral therapy (ART) of people living with HIV in Latin America and Caribbean, report the methods used to measure adherence and describe the factors associated with poor adherence among the selected studies.

METHODS

We electronically searched published studies up to July 2016 on the PubMed, Web of Science and Virtual Health Library (Latin America and the Caribbean Regional Portal); considering the following databases: MEDLINE, LILACS, PAHO and IBECS. Two independent reviewers selected and extracted data on ART adherence and study characteristics. Pooled estimate of adherence was derived using a random-effects model. Risk of bias in individual studies was assessed independently by two investigators using the Risk of Bias Assessment tool for Non-randomized Studies (RoBANS).

RESULTS AND DISCUSSION

The meta-analysis included 53 studies published between 2005 and 2016, which analysed 22,603 people living with HIV in 25 Latin America and Caribbean countries. Overall adherence in Latin America and Caribbean was 70% (95% CI: 63-76; I²  = 98%), similar to levels identified by studies conducted in high-income regions. Self-report was the most frequently used method to measure adherence. Subgroup analysis showed that adherence was higher for the shortest recall time frame used, as well as in countries with lower income level, Gross National Income (GNI) per capita and Human Development Index (HDI). Studies reported diverse adherence barriers, such as alcohol and substance misuse, depression, unemployment and pill burden.

CONCLUSIONS

Our study suggests that adherence to ART in Latin America and Caribbean may be below the sufficient levels required for a successful long-term viral load suppression.

Comparison of the predictive performance of adherence measures for virologic failure detection in people living with HIV: a systematic review and pairwise meta-analysis

A critical feature of an adherence assessment tool is its ability to predict virologic failure in people living with HIV (PLHIV). We, therefore, aimed to compare the predictive performance of commonly used adherence measures. We systematically searched MEDLINE, Embase and LILACS up to February 2018, to identify relevant observational studies comparing the effects of any two of the following adherence measurements on virologic outcomes: electronic monitoring, pill count, pharmacy refill, self-report and physician assessment. We analyzed data by pairwise meta-analyzes with a random-effects model. The proportion of virologic failures among non-adherent participants in each adherence measure was used to calculate the odds ratio (OR), with 95% Confidence Intervals (95%CI). Heterogeneity was assessed, with potential causes identified by sensitivity and subgroup analysis. We included 38 studies with individual patient data for 18,010 patients. All possible comparisons between pairs of the five adherence measures were considered and a total of nine comparison groups could be established. Meta-analysis suggested that self-report was a better predictor of virologic failure than pill count when the recall period was within one week (OR: 2.35, 95%CI: 1.07-5.18, p = 0.03). Physician assessment had higher odds of predicting virologic failure than did either self-report (OR: 2.63, 95%CI: 1.37-5.26, p < 0.01) or pharmacy refill (OR: 3.57, 95%CI: 1.69-7.14, p < 0.001). There was no difference in the predictive performance between any of the other measures that we were able to compare (p > 0.05). The combination of multiple measures did not increase the predictive value when compared to any of the measures alone. Low-cost and simple adherence measures such as self-report predict virologic failure better than or equally well as objective measures. Our results suggest that there is no need to use expensive or time-consuming adherence measures when the objective is to identify PLHIV at risk of treatment failure.

Short Communication: Bioequivalence of Tenofovir and Emtricitabine After Coencapsulation with the Proteus Ingestible Sensor

Adherence to tenofovir disoproxil fumarate/emtricitabine (TDF/FTC, Truvada^®) is the primary determinant of HIV pre-exposure prophylaxis (PrEP) efficacy. Despite its importance, limitations exist in current methods of adherence quantification, restricting their implementation in the clinic. Proteus Discover (Proteus Digital Health^®) can measure the time of each dose using an ingestible sensor that is coencapsulated with medication. In this study, the bioequivalence of coencapsulated TDF/FTC with the Proteus sensor was compared relative to unencapsulated drug. This was a 1:1 randomized cross-over study in which healthy participants received a single dose of unencapsulated and coencapsulated TDF/FTC. A 14-day washout separated each period. Blood was collected at predose and at 0.25, 0.5, 1, 2, 4, 6, 10, 24, 48, and 72 h postdose. Plasma concentrations were determined by LC-MS/MS methods, with a 10 ng/mL lower limit of quantitation (LLOQ) for both tenofovir (TFV) and FTC. Noncompartmental analysis was carried out with Phoenix^® WinNonlin^® for maximum concentrations (C_max), area under the concentration-time curve from time 0 to the last measured time point (AUC_last) and AUC extrapolated to infinity (AUC_inf). Geometric mean ratios were calculated for each parameter and bioequivalence was defined as the 90% confidence interval (CI) of each ratio being within 80%-125%. Twenty-four participants (11 males; 19 white, 3 African American, and 2 Hispanic) completed both visits. Mean ± SD age was 28 ± 4 years and weight was 74 ± 14 kg. The 90% CIs for TFV C_max, AUC_last, and AUC_inf were 89%-119%, 94%-111%, and 96%-111%, respectively. The 90% CIs for FTC C_max, AUC_last, and AUC_inf were 96%-120%, 96%-108%, and 96%-108%, respectively. Bioequivalence was observed for the coencapsulation of TDF/FTC with the Proteus ingestible sensor, as assessed by a rigorously conducted pharmacokinetic study. Future studies will evaluate the utility and effectiveness of the sensor system as a tool to monitor PrEP adherence in clinical settings.

Monitoring of Delay to Pharmacy Refill in Assessing Adherence to Antiretroviral Therapy

BACKGROUND

Adherence to antiretroviral (ARV) therapy remains a major challenge in HIV therapeutics.

OBJECTIVE

To assess the adherence to ARV therapy by measuring the delay in monthly refilling of ARV drugs using pharmacy records and to correlate this with HIV plasma RNA measurements and CD4⁺ cell count.

METHOD

Records of 170 HIV-positive patients were examined to identify HIV viral load (VL)/CD4⁺ results and the time interval to refill ARVs at the pharmacy. The correlation between the number of days missed to refill ARVs and plasma HIV-RNA detectability/CD4⁺ count was performed using the Spearman's correlation coefficient (r).

RESULTS

Fewer days missed to refill ARV was positively correlated with undetectable VL and increase in CD4⁺ count (r = 0.407 and 0.237, respectively). Increase in adherence was correlated with longer retention in the cohort (r = 0.208).

CONCLUSION

Monitoring the delay to pick up ARVs from the pharmacy can be an important and simple tool to identify patients requiring assessment of their adherence.

Monitoring self-reported adherence to antiretroviral therapy in public HIV care facilities in Brazil: A national cross-sectional study

INTRODUCTION

Patient adherence to antiretroviral therapy (ART) is critical for HIV treatment success. Monitoring rates of adherence in public HIV outpatient care facilities can improve outcomes in Brazil where ART is universally available.

METHODS

We conducted a national cross-sectional survey of ART adherence in 2010. Participants were selected using a multistage probability sample. First, HIV outpatient care facilities were stratified according to 7 Organizational Quality Classification (OQC) groups and regions. Second, 1 or 2 facilities were selected per region for each OQC group. Finally, patients were randomly selected at each facility. In a first component, patients were invited to answer to a web-based questionnaire (WebAd-Q), a validated self-reported tool that includes 3 questions on adherence to ART in the past 7 days (time scheduling-timing, drug regimen-medication, and pill counts-dose), herein named indicators of potential nonadherence (IPN). In addition, a subsample of participants were interviewed in order to obtain further data on sociodemographic and clinical characteristics (second component). The proportion of each IPN was estimated using weighted data to account for the sampling design with 95% confidence interval (CI) and descriptive analysis was carried out.

RESULTS

Fifty-five facilities were chosen and 2424 patients completed the WebAd-Q in the first component of the study, while 598 patients were interviewed for the second component. The weighted proportions of the IPN were 50.9%, 31.8%, and 19.5%, for timing, medication, and dose, respectively, while11.7% had all 3 indicators, varying from 5.9% in the Southeast and 21.9% in the Northeast regions. Overall, 61.1% of the patients had at least 1 IPN (95% CI: 58.5-63.7%). Patients reporting depression symptoms, illicit drug use and those who missed medical appointments had worse nonadherence outcomes.

CONCLUSIONS

Overall, there was a high proportion of all indicators IPN and timing was the main component associated with low adherence. Although these indicators may not necessarily indicate individual nonadherence, they represent a worrisome scenario in the public Brazilian HIV care facilities. On a routine basis, these facilities can identify gaps in providing counseling and ART orientation to their clientele and develop innovative strategies to prevent nonadherence.

Identification of the Medication Regimen Complexity Index as an Associated Factor of Nonadherence to Antiretroviral Treatment in HIV Positive Patients

BACKGROUND

Multiple studies have identified a relationship between the complexity of a medication regimen and non-adherence. However, most studies in people who live with HIV (PLWH) have focused on antiretroviral use and have failed to consider the impact of other medications.

OBJECTIVE

The aim of our study is to identify the Medication Regimen Complexity Index (MRCI) as an associated factor for nonadherence to antiretroviral treatment (ART). The secondary aim is to analyze the relationship between clinical and pharmacotherapeutical variables and adherence to antiretroviral treatment and to generate an adherence model.

METHODS

A transversal, observational study. Patients included were PLWH over 18 years of age on active antiretroviral therapy. Patients who participated in clinical trials or who did not meet the inclusion criteria were excluded. We had studied HIV transmission mode, viral load, treatment status, number of comorbidities and complexity index as factors associated with adherence to ART.

RESULTS

We included 619 patients in the study. Number of comorbidities ( p = 0.021; OR = 1.038-1.570); viral load ( p = 0.023; OR = 1.108-4.505) and MRCI ( p < 0.001; OR = 1.138-1.262) (ART and concomitant treatment) were the independent associated factors to ART nonadherence. The value of the Hosmer and Lemeshow test confirmed the validity of this model (P = 0.333).

CONCLUSION

A higher MRCI was associated with non-adherence. Therefore, the regimen complexity calculation may be appropriate in daily practice for identifying patients at a higher risk of becoming non-adherent.

Use of pharmacy records to measure treatment adherence: a critical review of the literature

The current frame of reference on adherence to pharmacotherapy includes a set of behaviors experienced by the user, with observation of the detailed and continuous history of the use of each dose of the medication. Indicators based on pharmacy records have been used to measure adherence. The current review aimed to identify and describe indicators based on pharmacy records and to discuss their adequacy and limitations for measuring adherence. An exploratory literature review was conducted in three databases using the terms "adherence", "pharmacy records/administrative data", and "measure" to compose the descriptors for the selection of 81 articles and the elaboration of a chart with the denomination, sources, methods for calculation, description, and interpretation of the operational and referential meaning of 14 indicators. Given the most recent taxonomy for adherence proposed in the literature, we concluded that the indicators can be useful for identifying patients with medication-seeking behavior-related problems and analysis of persistence. The distance between supply-related events and difficulties in treatment follow-up can influence an analysis based exclusively on the use of these indicators.

Survival benefits of antiretroviral therapy in Brazil: a model-based analysis

Objective

In Brazil, universal provision of antiretroviral therapy (ART) has been guaranteed free of charge to eligible HIV-positive patients since December 1996. We sought to quantify the survival benefits of ART attributable to this programme.

Methods

We used a previously published microsimulation model of HIV disease and treatment (CEPAC-International) and data from Brazil to estimate life expectancy increase for HIV-positive patients initiating ART in Brazil. We divided the period of 1997 to 2014 into six eras reflecting increased drug regimen efficacy, regimen availability and era-specific mean CD4 count at ART initiation. Patients were simulated first without ART and then with ART. The 2014-censored and lifetime survival benefits attributable to ART in each era were calculated as the product of the number of patients initiating ART in a given era and the increase in life expectancy attributable to ART in that era.

Results

In total, we estimated that 598,741 individuals initiated ART. Projected life expectancy increased from 2.7, 3.3, 4.1, 4.9, 5.5 and 7.1 years without ART to 11.0, 17.5, 20.7, 23.0, 25.3, and 27.0 years with ART in Eras 1 through 6, respectively. Of the total projected lifetime survival benefit of 9.3 million life-years, 16% (or 1.5 million life-years) has been realized as of December 2014.

Conclusions

Provision of ART through a national programme has led to dramatic survival benefits in Brazil, the majority of which are still to be realized. Improvements in initial and subsequent ART regimens and higher CD4 counts at ART initiation have contributed to these increasing benefits.

Characteristics of HIV patients who missed their scheduled appointments

OBJECTIVE

To analyze whether sociodemographic characteristics, consultations and care in special services are associated with scheduled infectious diseases appointments missed by people living with HIV.

METHODS

This cross-sectional and analytical study included 3,075 people living with HIV who had at least one scheduled appointment with an infectologist at a specialized health unit in 2007. A secondary data base from the Hospital Management & Information System was used. The outcome variable was missing a scheduled medical appointment. The independent variables were sex, age, appointments in specialized and available disciplines, hospitalizations at the Central Institute of the Clinical Hospital at the Faculdade de Medicina of the Universidade de São Paulo, antiretroviral treatment and change of infectologist. Crude and multiple association analysis were performed among the variables, with a statistical significance of p ≤ 0.05.

RESULTS

More than a third (38.9%) of the patients missed at least one of their scheduled infectious diseases appointments; 70.0% of the patients were male. The rate of missed appointments was 13.9%, albeit with no observed association between sex and absences. Age was inversely associated to missed appointment. Not undertaking anti-retroviral treatment, having unscheduled infectious diseases consultations or social services care and being hospitalized at the Central Institute were directly associated to missed appointments.

CONCLUSIONS

The Hospital Management & Information System proved to be a useful tool for developing indicators related to the quality of health care of people living with HIV. Other informational systems, which are often developed for administrative purposes, can also be useful for local and regional management and for evaluating the quality of care provided for patients living with HIV.

Does Food Insecurity Undermine Adherence to Antiretroviral Therapy? A Systematic Review

A growing body of research has identified food insecurity as a barrier to antiretroviral therapy (ART) adherence. We systematically reviewed and summarized the quantitative literature on food insecurity or food assistance and ART adherence. We identified nineteen analyses from eighteen distinct studies examining food insecurity and ART adherence. Of the thirteen studies that presented an adjusted effect estimate for the relationship between food insecurity and ART adherence, nine found a statistically significant association between food insecurity and sub-optimal ART adherence. Four studies examined the association between food assistance and ART adherence, and three found that ART adherence was significantly better among food assistance recipients than non-recipients. Across diverse populations, food insecurity is an important barrier to ART adherence, and food assistance appears to be a promising intervention strategy to improve ART adherence among persons living with HIV. Additional research is needed to determine the effectiveness and cost-effectiveness of food assistance in improving ART adherence and other clinical outcomes among people living with HIV in the era of widespread and long-term treatment.

Pharmacy refill adherence outperforms self-reported methods in predicting HIV therapy outcome in resource-limited settings

Background

Optimal adherence to antiretroviral therapy is critical to prevent HIV drug resistance (HIVDR) epidemic. The objective of the study was to investigate the best performing adherence assessment method for predicting virological failure in resource-limited settings (RLS).

Method

This study was a single-centre prospective cohort, enrolling 220 HIV-infected adult patients attending an HIV/AIDS Care and Treatment Centre in Dar es Salaam, Tanzania, in 2010. Pharmacy refill, self-report (via visual analog scale [VAS] and the Swiss HIV Cohort study-adherence questionnaire), pill count, and appointment keeping adherence measurements were taken.

Univariate logistic regression (LR) was done to explore a cut-off that gives a better trade-off between sensitivity and specificity, and a higher area under the curve (AUC) based on receiver operating characteristic curve in predicting virological failure. Additionally, the adherence models were evaluated by fitting multivariate LR with stepwise functions, decision trees, and random forests models, assessing 10-fold multiple cross validation (MCV). Patient factors associated with virological failure were determined using LR.

Results

Viral load measurements at baseline and one year after recruitment were available for 162 patients, of whom 55 (34%) had detectable viral load and 17 (10.5%) had immunological failure at one year after recruitment. The optimal cut-off points significantly predictive of virological failure were 95%, 80%, 95% and 90% for VAS, appointment keeping, pharmacy refill, and pill count adherence respectively. The AUC for these methods ranged from 0.52 to 0.61, with pharmacy refill giving the best performance at AUC 0.61.

Multivariate logistic regression with boost stepwise MCV had higher AUC (0.64) compared to all univariate adherence models, except pharmacy refill adherence univariate model, which was comparable to the multivariate model (AUC = 0.64). Decision trees and random forests models were inferior to boost stepwise model.

Pharmacy refill adherence (<95%) emerged as the best method for predicting virological failure. Other significant predictors in multivariate LR were having a baseline CD4 T lymphocytes count < 200 cells/μl, being unable to recall the diagnosis date, and a higher weight.

Conclusion

Pharmacy refill has the potential to predict virological failure and to identify patients to be considered for viral load monitoring and HIVDR testing in RLS.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-1035) contains supplementary material, which is available to authorized users.