Cost of behavioral interventions utilizing electronic drug monitoring for antiretroviral therapy adherence.

Effective antiretroviral therapy (ART) has led to durable viral load suppression and reduced morbidity and mortality.1,2 However these benefits are dependent on high levels of patient adherence which is difficult, especially over time.3,4 While the accepted definition of adherence for nearly all other chronic diseases is ≥80% of doses taken, early studies suggested that near-perfect ART adherence (>95%) was necessary to achieve these positive outcomes.5,6 More recent research indicates that the required level of adherence associated with viral suppression may be lower than originally thought and may vary with the type of ART being taken.7 Nevertheless, poor adherence leads to the development of resistance8,9 and subsequent reduction in viable treatment options for patients9 and is therefore an important clinical issue. HIV treatment failure without resistance is usually attributable to problems with adherence.10,11 Moreover poorer adherence may result in treatment failure and counteractively increase drug costs by necessitating the use of more expensive ARVs.11 The economic burden of regimen failure and HIV disease progression is huge. Recently a study estimated the economic burden of regimen failure and highlighted “the importance of ensuring optimal initial therapy choices and regimen succession”.12 Therefore investment in adherence improvement interventions may be worthwhile to reduce expensive burden of treatment failure. Over the last decade, an array of behavioral strategies to increase adherence to antiretroviral therapy (ART) have been examined. While several experimental interventions have been associated with improved adherence and/or HIV RNA suppression, findings have been inconsistent across studies.13–18 Most importantly, which intervention components are responsible for observed adherence gains and the costs associated with implementing them is still unclear. Clinicians are left to their own devises to determine which intervention aspects are worth the expense of implementing in their settings and researchers lack critical cost data to guide the planning of research studies. Although some cost analyses of behavioral ART adherence interventions have been performed, they rely on simulated models and lack real world cost assessment.19–22 While the results of these studies suggest positive cost effectiveness results of behavioral interventions, the data has limited utility in guiding the design of contemporary adherence interventions for research or practice. Although conventional methods were used, simulation models are based on assumptions and extrapolations. Other shortcomings include outdated source costs, observed therapy costs based on tuberculosis treatment adherence models, and models based on obsolete ART regimens and guidelines.29–22 Likewise, no study has analyzed potential costs of utilizing an electronic drug monitor (the current gold-standard) to verify adherence rates. Given the deleterious impact and cost of non-adherence, clinic settings are going to implement adherence interventions making real world cost information critical. Both behavioral interventions and modified directly observed therapy (mDOT) have been shown to be feasible adherence interventions in a variety of populations.23–36 Many studies have used electronic drug monitoring (EDM) systems to track adherence; however, few studies have also reported the actual costs of interventions combined with EDM.37–42 Consequently, costs of improving adherence using behavioral interventions, especially when utilizing mDOT and EDM, are underreported in the literature. The goal of this cost analysis was to provide a real world perspective on not only the costs associated with behavioral adherence intervention, mDOT, and using EDM in a clinical trial, but also the potential costs associated with adapting these interventions and EDM for usual clinical care. By separating out the costs of the adherence intervention components, the research related costs, and adherence monitoring costs, individuals can make informed decisions when selecting adherence support pieces to transfer to future studies or practice.