Disparities in Rates of HIV Treatment Initiation and Viral Load Suppression across US States, 2001–2007
David Hanna*1, K Gebo1, N Hessol2, M Horberg3, G Kirk1, M Kitahata4, S Napravnik5, T Sterling6, J Willig7, S Gange1, and North American AIDS Cohort Collaboration on Res and Design (NA-ACCORD) of IeDEA
1Johns Hopkins Univ, Baltimore, MD, US; 2Univ of California, San Francisco, US; 3Kaiser Permanente, Rockville, MD, US; 4Univ of Washington, Seattle, US; 5Univ of North Carolina at Chapel Hill, US; 6Vanderbilt Univ, Nashville, TN, US; and 7Univ of Alabama at Birmingham, US
Background: Improving access to care and reducing HIV-related health disparities are priorities of the US National HIV/AIDS Strategy (NHAS). We examined rate differences in treatment initiation and viral load suppression by state of residence, to determine if geography influences these important NHAS goals.
Methods: The North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) is a collaboration of >20 cohort studies of HIV-infected individuals in North America. Among persons newly eligible to initiate cART between 2001 and 2007 based on clinical guidelines at that time (AIDS-defining event or CD4+ count falling below 350 cells/µL) from 13 US cohorts, we estimated cART initiation rates within 6 months of eligibility per 100 person-years (PY), by state of residence. Separately, we estimated state-specific HIV viral load suppression (<500 copies/mL) rates within one year, per 100 PY. We used Poisson regression to calculate predicted rates evaluated at the mean of all co-variates (age; race/ethnicity; sex; transmission risk; CD4+ count; HIV viral load; history of ART, substance abuse, mental illness; year of eligibility; type of cohort [clinical vs interval]). While 29 states are represented, we report rates for 11 states (AL, CA, CO, FL, MD, NC, NY, OH, PA, TN, WA) with ≥50 eligible participants and ≥500 participants in the overall collaboration.
Results: Three thousand persons newly eligible for cART initiation contributed 1193 and 1952 PY to each respective analysis (cART initiation, viral load suppression). Overall, the adjusted cART initiation rate was 67/100 PY (95%CI 62 to 72). Among the 11 selected states, the cART initiation rate ranged from 53 (95%CI 29 to 78) to 181 (95%CI 93 to 269), representing a 3.4-fold relative difference (Pheterogeneity <0.0001). The adjusted viral load suppression rate among all persons was 52/100 (95%CI 49 to 56) and ranged from 37 (95%CI 22 to 51) to 97 (95%CI 59 to 136), a 2.6-fold difference (Pheterogeneity <0.0001). cART initiation and viral load suppression rates were highly correlated within states (r = 0.73), and each rate increased significantly over time (7% and 5% per year, both p <0.01).
Conclusions: Among persons newly eligible to begin cART, we observed differences in initiating therapy and short-term viral load suppression by state of residence that persisted in adjusted analyses. Further assessment of state-level barriers to treatment initiation, in addition to individual- and clinic-level factors, may help to inform the strategy to achieve the goals of NHAS.