Predictors of non adherence to antiretroviral therapy at an urban HIV care and treatment center in Tanzania

Raphael Z Sangeda,1,2 Fausta Mosha,3 Said Aboud,4 Appolinary Kamuhabwa,5 Guerino Chalamilla,6,† Jurgen Vercauteren,2 Eric Van Wijngaerden,7 Eligius F Lyamuya,4 Anne-Mieke Vandamme2,8 1Department of Pharmaceutical Microbiology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania; 2Department of Microbiology and Immunology, Rega Institute for Medical Research, Clinical and Epidemiological Virology, KU Leuven – University of Leuven, Leuven, Belgium; 3Ministry of Health, Community Development, Gender, Elderly and Children, Dar es Salaam, Tanzania; 4Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania; 5Department of Clinical Pharmacy and Pharmacology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania; 6Management and Development for Health (MDH), Dar es Salaam, Tanzania; 7Department of General Internal Medicine, University Hospitals, KU Leuven – University of Leuven, Belgium; 8Center for Global Health and Tropical Medicine, Unidade de Microbiologia, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal †Dr Guerino Chalamilla passed away in November 2015 Background: Measurement of adherence to antiretroviral therapy (ART) can serve as a proxy for virologic failure in resource-limited settings. The aim of this study was to determine the factors underlying nonadherence measured by three methods. Patients and methods: This is a prospective longitudinal cohort of 220 patients on ART at Amana Hospital in Dar es Salaam, Tanzania. We measured adherence using a structured questionnaire combining a visual analog scale (VAS) and Swiss HIV Cohort Study Adherence Questionnaire (SHCS-AQ), pharmacy refill, and appointment keeping during four periods over 1 year. Overall adherence was calculated as the mean adherence for all time points over the 1 year of follow-up. At each time point, adherence was defined as achieving a validated cutoff for adherence previously defined for each method. Results: The proportion of overall adherence was 86.4% by VAS, 69% by SHCS-AQ, 79.8% by appointment keeping, and 51.8% by pharmacy refill. Forgetfulness was the major reported reason for patients to skip their medications. In multivariate analysis, significant predictors to good adherence were older age, less alcohol consumption, more advanced World Health Organization clinical staging, and having a lower body mass index with odds ratio (CI): 3.11 (1.55–6.93), 0.24 (0.09–0.62), 1.78 (1.14–2.84), and 0.93 (0.88–0.98), respectively. Conclusion: We found relatively good adherence to ART in this setting. Barriers to adherence include young age and perception of well-being. Keywords: self-report, appointment keeping, pharmacy refill, adherence barriers, resource-limited settings, AIDS