Factors Contributing to Poor ART Adherence, HIV-1 Drug Resistance Explored

HIV-positive patients in the United States face significant challenges associated with poor adherence to antiretroviral therapy (ART) and HIV-1 drug resistance, according to a study published in AIDS and Behavior.

To estimate the rates of ART adherence as well as the prevalence of HIV-1 drug resistance in the US, investigators analyzed data from the Integrated Dataverse (IDV) from the Symphony Health database and the Monogram/LabCorp Database, respectively, from January 1, 2015 to September 30, 2017.

Data from IDV included adjudicated prescription, medical, and hospital claims for all payment types. Patients were included for analysis if they were aged ≥18 years with HIV-1 diagnosis during the identification period (July 1, 2015 to September 30, 2016), and had pharmacy claims for antiretrovirals (ARV) within 14 days of each other or at least 1 pharmacy claim for a single-tablet regimen (STR). The Monogram/LabCorp Database included genotypic drug resistance data for commercially available HIV treatments (ie, nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, protease inhibitors, integrase inhibitors). 

Outcome measures included the rates of adherence to ART and the prevalence of HIV-1 drug resistance. “Adherence to ART was measured by the proportion of days covered (PDC), which is the sum of days during the observation period which spans over 12 months after the index date and covered by either at least 2 ARVs or 1 STR, divided by a fixed number of available days in the observation period,” the authors explained. 

Social determinants of health (SDoH) (eg, employment status, education and poverty level, insurance coverage), healthcare resource utilization [HCRU] (eg, linkage to HIV medical center, medicaid expansion status), and other HIV-related health outcomes (eg, HIV mortality, prevalence, diagnoses and viral suppression), were also measured and analyzed. 

A total of 169,545 patients were included in the adherence analyses with an average PDC of 0.72. At the national level, 45% of patients were considered to have poor adherence (PDC <80%), 30% with suboptimal adherence (PDC ≥80-<95%), and only 25% achieved optimal adherence (PDC ≥95%) during the 12-month follow-up period. HIV-1 drug resistance was evident in 31% of isolates. 

At the state level, southern states were found to have a higher rate of poor adherence to ART, with more than 50% of patients being poorly adherent in most of the states. Three out of the 5 states with the highest HIV prevalence were also found in the South.

A total of 95,956 isolates were included in the drug resistance analyses. Across all states, HIV-1 drug resistance ranged from 20-54%. Among the 5 states with the highest prevalence of HIV-1 drug resistance, 3 states had more than 40% of patients with poor adherence to ART. 

Investigators also found a correlation between the prevalence of poor/suboptimal adherence and HIV prevalence, diagnoses, mortality and viral suppression rates. States with a higher prevalence of poor or poor/suboptimal adherence were associated with higher HIV prevalence (P =.002), lower diagnosis rates for new HIV infection (P <.001), higher mortality rates (P =.003), and lower viral suppression rates (P =.065). Other factors associated with poor/suboptimal ART adherence included lower education (P =.012), poverty (P =.057), unemployment (P =.015), female gender (P =.156 for male gender), non-white race (P <.001), and lack of health insurance coverage (P =.04). 

Additionally, states with higher resistance rates were observed to have a higher HIV prevalence (P =.048). Poor adherence was associated with linkage to care, but was not found to be statistically significant (P =.076). The authors noted that no correlation was observed between adherence or resistance and Medicaid expansion status.

“This study is one of the first in the US to provide a comprehensive understanding of the current status of adherence to ART, the prevalence of resistance to HIV drugs, SDoH that could be associated with poor or suboptimal adherence and ART resistance, and the impact of Medicaid expansion,” the authors stated. They concluded that SDoH factors should be considered in selecting ARTs, and measures must be adopted to help improve adherence and prevent the development of resistance, such as the use of STRs and regimens with a high genetic barrier to resistance, especially in US regions where HIV prevalence is high, adherence is suboptimal, and health determinants are poor. 

Reference

Benson C, Wang X, Dunn KJ, et al. Antiretroviral adherence, drug resistance, and the impact of social determinants of health in HIV-1 Patients in the US [published online June 2, 2020]. AIDS and Behavior. doi: 10.1007/s10461-020-02937-8