An analysis of electronically monitored adherence to antiretroviral medications

Hydroxyurea mobile directly observed therapy versus standard monitoring in patients with sickle cell anemia: a phase 2 randomized trial

BACKGROUND

Sickle cell anemia (SCA) prevalence remains high in sub-Saharan Africa. Long-term treatment with hydroxyurea (HU) increases survival, however, poor adherence to treatment could limit effectiveness. Whilst HU treatment adherence is currently high, this might decrease over time.

METHODS

We conducted a single-center, randomized, open-label, parallel group phase 2 controlled clinical trial to determine whether mobile Directly Observed Therapy (m-DOT) increases HU treatment adherence (NCT02844673). Eligible participants were adults with homozygous SCA. People on a chronic blood transfusion program, with hemoglobin (Hb) A levels greater than 20% of the total Hb, total Hb less than 4 g/dL, pregnant or HIV positive were excluded. After a 3-month pre-treatment period participants were randomized to either m-DOT or standard monitoring arm. All participants received smart mobile phones and were treated with HU (15 mg/kg) daily for three months. In the m-DOT arm, drug intake was video recorded on cell phone by the participant and the video sent to the study team. The primary objective was to evaluate the effect of m-DOT on adherence to HU treatment by medication possession ratio (MPR).

RESULTS

Of the 86 participants randomized, 76 completed the trial (26.13 ± 6.97 years, 63.5 % female). Adherence was high (MPR > 95 %) in both groups, 29 (80.6 %) in m-DOT versus 37 (94.9 %) in the standard monitoring arm (P = 0.079). No HU treatment was withheld from participants due to safety concerns.

CONCLUSIONS

m-DOT did not increase adherence to HU treatment. We recommend that further testing in larger trials with a longer follow up period be undertaken.

Medication adherence in older people with rheumatoid arthritis is lower according to electronic monitoring than according to pill count

Objectives

Suboptimal medication adherence is a serious problem in the treatment of chronic inflammatory diseases. To measure medication adherence, electronic monitoring is regarded as superior to pill count. GLORIA is an ongoing two-year trial on the addition of low-dose (5 mg/d) prednisolone or placebo to standard care in older people (65+ years) with RA. During the entire trial, adherence is measured with electronic caps, and with pill counts. The objective is to describe medication adherence patterns, and to compare the adherence results of the two methods.

Methods

The recorded adherence patterns of patients (blinded for treatment group) were classified according to descriptive categories. The cutoff for good adherence was set at 80% of prescribed pills taken.

Results

Trial inclusion closed in 2018 at 451 patients, but trial follow-up is ongoing; the current dataset contains adherence data of 371 patients. Mean number of recorded 90-day periods per patient was 4 (range 1–8). Based on pill count over all periods, 90% of the patients had good adherence; based on cap data, only 20%. Cap data classified 30% of patients as non-user (<20% of days an opening) and 40% as irregular user (different adherence patterns, in or between periods).

Conclusion

In our trial of older people with RA, the majority appeared to be adherent to medication according to pill count. Results from caps conflicted with those of pill counts, with patterns suggesting patients did not use the bottle for daily dispensing, despite specific advice to do so.

Trial registration

NCT02585258. ClinicalTrials.gov (https://www.clinicaltrials.gov/)

Predicting short-term interruptions of antiretroviral therapy from summary adherence data: Development and test of a probability model

Antiretroviral therapy (ART) for HIV is vulnerable to unplanned treatment interruptions-consecutively missed doses over a series of days-which can result in virologic rebound. Yet clinicians lack a simple, valid method for estimating the risk of interruptions. If the likelihood of ART interruption could be derived from a convenient-to-gather summary measure of medication adherence, it might be a valuable tool for both clinical decision-making and research. We constructed an a priori probability model of ART interruption based on average adherence and tested its predictions using data collected on 185 HIV-infected, treatment-naïve individuals over the first 90 days of ART in a prospective cohort study in Mbarara, Uganda. The outcome of interest was the presence or absence of a treatment gap, defined as >72 hours without a dose. Using the pre-determined value of 0.50 probability as the cut point for predicting an interruption, the classification accuracy of the model was 73% (95% CI = 66%- 79%), the specificity was 87% (95% CI = 79%- 93%), and the sensitivity was 59% (95% CI = 48%- 69%). Overall model performance was satisfactory, with an area under the receiver operator characteristic curve (AUROC) of 0.85 (95% CI = 0.80-0.91) and Brier score of 0.20. The study serves as proof-of-concept that the probability model can accurately differentiate patients on the continuum of risk for short-term ART interruptions using a summary measure of adherence. The model may also aid in the design of targeted interventions.

Advancing the Science and Practice of Medication Adherence

Medication adherence remains a significant unmet challenge for optimizing patient outcomes. Recent advances in the conceptualization, measurement, and support of medication adherence offer fresh opportunities to make a meaningful impact on adherence-related behavior and outcomes. These advances emphasize the multifaceted and dynamic nature of medication adherence, provide novel methods for monitoring medication adherence in clinical care, and articulate a set of multilevel strategies to more effectively improve and sustain medication adherence. Here, we offer recommendations for how clinicians can better engage with, and benefit from, these innovations to improve patient medication adherence and associated treatment outcomes.

Binge drinking is associated with differences in weekday and weekend adherence in HIV-infected individuals

BACKGROUND

Understanding patterns of antiretroviral adherence and its predictors is important for designing tailored interventions. Alcohol use is associated with non-adherence. This study aimed to evaluate: (1) if there was a difference in weekday compared with weekend adherence in HIV-infected individuals from low and middle income countries (LMIC), and (2) whether binge drinking was associated with this difference.

METHODS

Data from a randomized trial conducted at 9 sites in 8 LMIC were analyzed. Microelectronic monitors were used to measure adherence. Differences between weekday and weekend adherence in each quarter (successive 12-week periods) were compared using Wilcoxon signed rank tests and predictors of adherence, including baseline binge drinking, were evaluated using Generalized Estimating Equations.

RESULTS

Data from 255 participants were analyzed: 49.8% were male, median age was 37 years and 28.6% enrolled in Haiti. At study entry, only 2.7% reported illicit substance use, but 22.3% reported binge drinking at least once in the 30 days prior to enrollment. Adherence was higher on weekdays than weekends (median percent doses taken: 96.0% vs 94.4%; 93.7% vs 91.7%; 92.6% vs 89.7% and 93.7% vs 89.7% in quarters 1-4 respectively, all p<0.001). Binge drinking at baseline and time on study were both associated with greater differences between weekday and weekend adherence.

CONCLUSIONS

Adherence was worse on weekends compared to weekdays: difference was small at treatment initiation, increased over time and was associated with binge drinking. Screening and new interventions to address binge drinking, a potentially modifiable behavior, may improve adherence in HIV-infected individuals in LMIC.

Novel Approaches for Visualizing and Analyzing Dose-Timing Data from Electronic Drug Monitors, or "How the 'Broken Window' Theory Pertains to ART Adherence"

Adherence to antiretroviral medications is usually expressed in terms of the proportion of doses taken. However, the timing of doses taken may also be an important dimension to overall adherence. Little is known about whether patients who mistime doses are also more likely to skip doses. Using data from the completed Adherence for Life randomized controlled trial, we created visual and statistical models to capture and analyze dose timing data collected longitudinally with electronic drug monitors (EDM). From scatter plots depicting dose time versus calendar date, we identified dominant patterns of dose taking and calculated key features [slope of line over calendar date; residual mean standard error (RMSE)]. Each was assessed for its ability to categorize subjects with 'sub-optimal' (<95 % of doses taken) using area under the receiver operating characteristic (AROC) curve analysis. Sixty eight subjects contributed EDM data, with ~300 to 400 observations/subject. While regression line slopes did not predict 'sub-optimal' adherence (AROC 0.51, 95 % CI 0.26-0.75), the variability in dose timing (RMSE) was strongly predictive (AROC 0.79, 95 % CI 0.62-0.97). Compared with the lowest quartile of RMSE (minimal dose time variability), each successive quartile roughly doubled the odds of 'sub-optimal' adherence (OR 2.1, 95 % CI 1.3-3.4). Patterns of dose timing and mistiming are strongly related to overall adherence behavior. Notably, individuals who skip doses are more likely to mistime doses, with the degree of risk positively correlated with the extent of dose timing variability.

Sexual Relationships Outside Primary Partnerships and Abstinence Are Associated With Lower Adherence and Adherence Gaps: Data From the Partners PrEP Ancillary Adherence Study

OBJECTIVE

To assess the role of sexual relationships on levels and patterns of adherence to medication for pre-exposure prophylaxis against HIV.

METHODS

We enrolled 1147 HIV-negative individuals in long-term serodiscordant relationships at 3 sites in Uganda from the Partners Pre-exposure Prophylaxis Study, a randomized placebo-controlled trial of daily oral tenofovir and emtricitabine/tenofovir. We used generalized estimation equations to assess the effects of sexual relationships on low adherence (<80%) and on gaps in adherence.

RESULTS

Fifty-three percent were male, 51% were 18-34 years and 24% were polygamous. Participants who reported sex in the past month with someone other than their primary partner and with <100% condom use were more than twice as likely to have low adherence [adjusted odds ratio (aOR) = 2.48, 95% CI: 1.70 to 3.62] compared with those who had sex with only their primary partners and 100% condom use. Using the same reference group, those who abstained from sex in the previous month had 30% increased odds of low adherence (aOR = 1.30, 95% CI: 1.05 to 1.62) and participants in nonpolygamous marriages who reported sex with both their primary and other partners and <100% condom use were almost twice as likely to be low adherers (aOR = 1.76, 95% CI: 1.01 to 3.08). At least one 72-hour gap in adherence was seen in 598 participants (54.7%); 23.2% had at least one 1-week gap.

CONCLUSIONS

Risk of low overall adherence was higher in participants who reported sex outside primary partnerships and suboptimal condom use, as well as in those who abstained from sex. Adherence gaps were common, potentially creating risk for HIV acquisition.

Characterizing weekly self-reported antihypertensive medication nonadherence across repeated occasions

BACKGROUND

Little is known about weekly variability in medication nonadherence both between and within persons.

PURPOSE

To characterize medication nonadherence across repeated, closely spaced occasions.

METHODS

This prospective cohort study comprised four unannounced telephone assessment occasions, each separated by approximately 2 weeks. On each occasion, adult outpatients taking at least a single antihypertensive medication completed a measure of extent of, and reasons for, nonadherence.

RESULTS

Two hundred and sixty-one participants completed 871 (83%) of 1,044 occasions. Nonadherence was reported on 152 (17.5%) of 871 occasions by 93 (36%) of 261 participants. The most commonly endorsed reasons for nonadherence were forgetting (39.5%), being busy (23.7%), and traveling (19.7%). Among 219 participants completing at least three occasions, 50% of the variability in extent of nonadherence was a result of within-person fluctuations, and 50% was a result of between-person differences.

CONCLUSION

Interventions to reduce nonadherence should be informed by variability in the extent of nonadherence and specific reasons for nonadherence.

What puts heart failure patients at risk for poor medication adherence?

BACKGROUND

Medication nonadherence is a major cause of hospitalization in patients with heart failure (HF), which contributes enormously to health care costs. We previously found, using the World Health Organization adherence dimensions, that condition and patient level factors predicted nonadherence in HF. In this study, we assessed a wider variety of condition and patient factors and interactions to improve our ability to identify those at risk for hospitalization.

MATERIALS AND METHODS

Medication adherence was measured electronically over the course of 6 months, using the Medication Event Monitoring System (MEMS). A total of 242 HF patients completed the study, and usable MEMS data were available for 218 (90.1%). Participants were primarily white (68.3%), male (64.2%), and retired (44.5%). Education ranged from 8-29 years (mean, 14.0 years; standard deviation, 2.9 years). Ages ranged from 30-89 years (mean, 62.8 years; standard deviation, 11.6 years). Analyses used adaptive methods based on heuristic searches controlled by cross-validation scores. First, individual patient adherence patterns over time were used to categorize patients in poor versus better adherence types. Then, risk factors for poor adherence were identified. Finally, an effective model for predicting poor adherence was identified based on identified risk factors and possible pairwise interactions between them.

RESULTS

A total of 63 (28.9%) patients had poor adherence. Three interaction risk factors for poor adherence were identified: a higher number of comorbid conditions with a higher total number of daily medicines, older age with poorer global sleep quality, and fewer months since diagnosis of HF with poorer global sleep quality. Patients had between zero and three risk factors. The odds for poor adherence increased by 2.6 times with a unit increase in the number of risk factors (odds ratio, 2.62; 95% confidence interval, 1.78-3.86; P<0.001).

CONCLUSION

Newly diagnosed, older HF patients with comorbid conditions, polypharmacy, and poor sleep are at risk for poor medication adherence. Interventions addressing these specific barriers are needed.

Assessing adherence to antiretroviral therapy in randomized HIV clinical trials: a review of currently used methods

Antiretroviral therapy for the treatment of HIV infection requires high levels of adherence to both maintain plasma HIV RNA at undetectable levels and prevent the emergence of drug resistance. As adherence to treatment is a major criterion for the evaluation of therapeutic outcomes, randomized clinical trials (RCTs) conducted among HIV-infected patients commonly include an assessment of adherence. However, there is still no gold-standard tool for assessing adherence behaviors in HIV RCTs. The methods currently used to collect and analyze adherence data are varied, which makes the comparison of results between studies difficult. The scope of this article is to review and discuss the range of adherence measures currently used in RCTs conducted among HIV-infected adults.

Use of novel technology-based techniques to improve alcohol-related outcomes in clinical trials

With a better understanding of the biologic basis of alcohol dependence and the considerable financial burden of alcohol abuse and dependence, the number of alcohol-related clinical pharmacotherapy trials has been on the rise. Subsequently, the potential to find efficacious treatments is more promising. Unfortunately, alcohol-related trials face a number of challenges, as a result of the difficulties that arise from traditional and outdated methods to collect data and ensure medication adherence. Novel technology-based assessments, such as ecological momentary assessment, interactive voice response, transdermal sensor and medication-event monitoring system provide a prospective solution-albeit not without possible concerns-to the difficulties faced in alcohol-related clinical trials. Clinical trials are meant to define the efficacy of the treatment and to determine an effective and safe dosage. However, due to lack of adherence a drug could inappropriately or mistakenly be judged as ineffective for treating a specific disorder. The described technologies may be important tools to prevent false negatives in validating drug efficacy, to provide consistency in clinical trials and to improve available data regarding the study of pharmacotherapies for alcohol dependence.

Socioeconomic factors in adherence to HIV therapy in low- and middle-income countries

It is not clear what effect socioeconomic factors have on adherence to antiretroviral therapy (ART) among patients in low- and middle-income countries. We performed a systematic review of the association of socioeconomic status (SES) with adherence to treatment of patients with HIV/AIDS in low- and middle-income countries. We searched electronic databases to identify studies concerning SES and HIV/AIDS and collected data on the association between various determinants of SES (income, education, occupation) and adherence to ART in low- and middle-income countries. From 252 potentially-relevant articles initially identified, 62 original studies were reviewed in detail, which contained data evaluating the association between SES and adherence to treatment of patients with HIV/AIDS. Income, level of education, and employment/occupational status were significantly and positively associated with the level of adherence in 15 studies (41.7%), 10 studies (20.4%), and 3 studies (11.1%) respectively out of 36, 49, and 27 studies reviewed. One study for income, four studies for education, and two studies for employment found a negative and significant association with adherence to ART. However, the aforementioned SES determinants were not found to be significantly associated with adherence in relation to 20 income-related (55.6%), 35 education-related (71.4%), 23 employment/occupational status-related (81.5%), and 2 SES-related (100%) studies. The systematic review of the available evidence does not provide conclusive support for the existence of a clear association between SES and adherence to ART among adult patients infected with HIV/ AIDS in low- and middle-income countries. There seems to be a positive trend among components of SES (income, education, employment status) and adherence to antiretroviral therapy in many of the reviewed studies.

A proposal for quality standards for measuring medication adherence in research

A decade after widespread recognition that adherence to medication regimens is key to antiretroviral effectiveness, considerable controversy remains regarding a "gold standard" for adherence measurement. Each adherence measurement approach has strengths and weaknesses and each rests on specific assumptions. The range of assumptions regarding adherence measurement and the diversity with which each approach is implemented strongly suggest that the evaluation of a particular measure outside of the context in which it was used (e.g. the study's operational protocol) may result in undeserved confidence or lack of confidence in study results. The purpose of this paper is to propose a set of best practices across commonly used measurement methods. Recommendations regarding what information should be included in published reports regarding how adherence was measured are provided to promote improvement in the quality of measurement of medication adherence in research.

Secondary analysis of electronically monitored medication adherence data for a cohort of hypertensive African-Americans

BACKGROUND

Electronic monitoring devices (EMDs) are regarded as the "gold standard" for assessing medication adherence in research. Although EMD data provide rich longitudinal information, they are typically not used to their maximum potential. Instead, EMD data are usually combined into summary measures, which lack sufficient detail for describing complex medication-taking patterns. This paper uses recently developed methods for analyzing EMD data that capitalize more fully on their richness.

METHODS

Recently developed adaptive statistical modeling methods were used to analyze EMD data collected with medication event monitoring system (MEMS™) caps in a clinical trial testing the effects of motivational interviewing on adherence to antihypertensive medications in a cohort of hypertensive African-Americans followed for 12 months in primary care practices. This was a secondary analysis of EMD data for 141 of the 190 patients from this study for whom MEMS data were available.

RESULTS

Nonlinear adherence patterns for 141 patients were generated, clustered into seven adherence types, categorized into acceptable (for example, high or improving) versus unacceptable (for example, low or deteriorating) adherence, and related to adherence self-efficacy and blood pressure. Mean adherence self-efficacy was higher across all time points for patients with acceptable adherence in the intervention group than for other patients. By 12 months, there was a greater drop in mean post-baseline blood pressure for patients in the intervention group, with higher baseline blood pressure values than those in the usual care group.

CONCLUSION

Adaptive statistical modeling methods can provide novel insights into patients' medication-taking behavior, which can inform development of innovative approaches for tailored interventions to improve medication adherence.

Antiretroviral treatment adherence among HIV patients in KwaZulu-Natal, South Africa

Background

Successful antiretroviral treatment is dependent on sustaining high rates of adherence. In the southern African context, only a handful of studies (both quantitative and qualitative) have looked at the determinants including a health behaviour theory of adherence to antiretroviral therapy. The aim of this study is to assess factors including the information, motivation and behavioural skills model (IMB) contributing to antiretroviral (ARV) adherence six months after commencing ARVs at three public hospitals in KwaZulu-Natal, South Africa.

Methods

Using systematic sampling, 735 HIV-positive patients were selected prior to commencing on ART from outpatient departments from three hospitals and followed-up at six months and interviewed with a questionnaire.

Results

A good proportion of patients were found to be adherent using both adherence instruments (visual analog scale = VAS 82.9%; Adult AIDS Clinical Trials Group = AATCG 70.8%). After adjusting for significant socio-economic variables, both the VAS and the dose, schedule and food adherence indicator found levels of adherence amongst urban residents to be almost 3 times greater than that of rural residents. After adjusting for health-related variables, for both indicators better adherence was associated with low depression and poorer adherence was associated with poor environmental factors. Adjusted odds ratios for adherence when taking into account different behavioural variables were for both adherence indicators, discrimination experiences were associated with lower adherence, and higher scores in adherence information and behavioural skills were associated with higher adherence. For the VAS adherence indicator, higher social support scores were associated with higher adherence. For the dose, schedule and food adherence indicator, using herbal medicines for HIV was associated with lower adherence.

Conclusion

For the patients in this study, particularly those not living in urban areas, additional support may be needed to ensure patients are able to attend appointments or obtain their medications more easily. Adherence information and behavioural skills as part of the IMB model should be strengthened to improve adherence. Further psychological support is also required and patients' perceived need for ARTs should be routinely assessed.