Income Inequality Is Associated With Low Cumulative Antiretroviral Adherence in Persons With Human Immunodeficiency Virus

Frances Vernon; Mary Morrow; Samantha MaWhinney; Ryan Coyle; Stacey Coleman; Lucas Ellison; Jia-Hua Zheng; Lane Bushman; Jennifer J Kiser; Omar Galárraga; Peter L Anderson; Jose Castillo-Mancilla

doi:10.1093/ofid/ofaa391

Income Inequality Is Associated With Low Cumulative Antiretroviral Adherence in Persons With Human Immunodeficiency Virus

Open Forum Infect Dis. 2020 Aug 29;7(10):ofaa391. doi: 10.1093/ofid/ofaa391. eCollection 2020 Oct.

Authors

Affiliations

¹ School of Medicine, University of Colorado-Anschutz Medical Campus (AMC), Aurora, Colorado, USA.
² Department of Biostatistics and Bioinformatics, Colorado School of Public Health, Aurora, Colorado, USA.
³ Division of Infectious Diseases, School of Medicine, University of Colorado-AMC, Aurora, Colorado, USA.
⁴ Duke University Hospital, Durham, North Carolina, USA.
⁵ Colorado Antiviral Pharmacology Laboratory and Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-AMC, Aurora, Colorado, USA.
⁶ Brown University, School of Public Health, Providence, Rhode Island, USA.

Abstract

Background: The adherence biomarker tenofovir diphosphate (TFV-DP) in dried blood spots (DBS) is associated with viral suppression and predicts future viremia. However, its association with social determinants of health (SDoH) in people with human immunodeficiency virus (PWH) remains unknown.

Methods: Dried blood spots for TFV-DP were longitudinally collected from a clinical cohort of PWH receiving tenofovir disoproxil fumarate-based therapy (up to 3 visits over 48 weeks) residing in 5 Colorado counties. To assign SDoH, zip codes at enrollment were matched with SDoH data from AIDSVu (https://aidsvu.org/). The SDoH included household income, percentage living in poverty, education level, and income inequality (quantified using Gini coefficient, where 0 and 1 represent perfect income equality and inequality, respectively). Log-transformed TFV-DP concentrations were analyzed using a mixed-effects model to estimate percentage change (95% confidence interval) in TFV-DP for every significant change in the SDoH and adjusted for relevant covariates including age, gender, race, estimated glomerular filtration rate, body mass index, hematocrit, CD4⁺ T-cell count, antiretroviral drug class, and 3-month self-reported adherence.

Results: Data from 430 PWH totaling 950 person-visits were analyzed. In an adjusted analysis, income inequality was inversely associated with TFV-DP in DBS. For every 0.1 increase in the Gini coefficient, TFV-DP concentrations decreased by 9.2% (-0.5 to -17.1; P = .039). This remained significant after adjusting for human immunodeficiency virus viral suppression, where a 0.1 increase in Gini was associated with a decrease of 8.7% (-0.3 to -17.9; P = .042) in TFV-DP.

Conclusions: Higher income inequality was associated with lower cumulative antiretroviral adherence. These findings support the need for further research on how SDoH impact adherence and clinical care.

Keywords: adherence; dried blood spots; income inequality; social determinants of health; tenofovir diphosphate.

Abstract

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