Use of Multiple Methods to Measure Adherence to Antiretroviral Treatment in La Romana, Dominican Republic

Abstract

Objective. To develop a tool that measures levels of adherence to antiretroviral treatment (ART) in resource-poor settings, based on a combination of four methods for measuring adherence. Methods. Retrospective review of 500 medical records of people living with HIV, randomly selected from October 2017 to January 2020. Adherence to ART was measured by combining four measurement methods (coverage of prescribed ART, ART picked up at pharmacies, viral load, and self-reported adherence). Chi-squared tests were performed with p<0.05 for statistically significant differences and logistic binary regression to identify the probability of optimal and suboptimal adherence. Spearman tests were performed for correlation of categories, and Cronbach's alpha was used to measure the internal consistency of the tool. Results. We obtained 497 adherence scores. Of these, 307 (61.8%) users qualified as adherent, 141 (28.4%) as semi-adherent, and 49 (9.8%) as non-adherent. A higher probability of optimal adherence was found in groups aged 60 years and older (odds ratio [OR]: 1.6; CI95%: 0.8-3.5), with no difference between men and women (OR: 0.9; CI95%: 0.7-1.4). Spearman's test reported a relationship (r = 0.8) between viral load levels and final score, and Cronbach's alpha yielded modest internal consistency (α = 0.7). Conclusions. A tool was developed to measure adherence to ART in a resource-poor environment. The tool shows modest levels of internal consistency and a strong correlation between viral load and adherence.