The impact of neurobehavioral features on medication adherence in HIV: Evidence from longitudinal models

Abstract

Effective antiretroviral therapy has led to substantial improvements in health-related outcomes among individuals with HIV. Despite advances in HIV pharmacotherapy, suboptimal medication adherence remains a significant barrier to successful treatment. Although several factors have been associated with medication adherence in the extant literature, study assessing the effects of some of the neurobehavioral features specific to HIV has been limited. Moreover, although there is a growing body of literature measuring medication adherence in HIV prospectively, few employ advanced statistical methodologies suited to handle advanced models with multiple predictors that would strengthen our understanding of medication adherence trajectories in HIV. This study sought to integrate traditionally assessed predictors of medication adherence with neurobehavioral features of HIV in a longitudinal study of medication adherence to combined antiretroviral therapy (cART). The current study used multilevel modeling to examine a wide arrangement of categories of factors – demographic, medication related, psychosocial, and neurobehavioral – on medication adherence. The sample consisted of 235 HIV+ individuals whose medication adherence was monitored over the course of six months using electronic monitoring devices. After controlling for the effects of demographic, medication, and psychosocial factors, neurobehavioral features added predictive validity to the model. In the final model, simultaneously controlling for the effects of each of the predictors within all the categories, age, self-efficacy, executive functioning, apathy, and frequency of stimulant use emerged as unique individual predictors of average medication adherence across the 6-month study. Self-efficacy and irritability predicted changes in medication adherence over time. Adherence behavior is multidetermined. Adequate assessment of these factors, combined with timely intervention, appears to be warranted in order to boost adherence rates.

Keywords:

• HIV
• AIDS
• antiretroviral therapy
• adherence
• neurobehavioral
• psychosocial

Acknowledgements

This study was supported by National Institute of Drug Abuse Grant RO1 DA13799 awarded to Dr. Charles H. Hinkin as well as a supplement from the National Institute on Drug Abuse. Drs. Stella E. Panos and Sapna M. Patel are supported by National Institute of Mental Health Training Grant T32 MH19535. Additional support is provided to Dr. Panos by the National Institute of Health Loan Repayment Award. Dr. Thames is supported by the National Institute of Mental Health Career Development Award K23MH095661 (PI: A. Thames).

Supplemental Material

All Supplemental Material is available alongside this article on www.tandfonline.com - go to http://dx.doi.org/10.1080/09540121.2013.802275