Cost of Treatment in a US Commercially Insured, HIV-1-Infected Population

Objective: Recent treatment patterns and cost data associated with HIV in the United States are limited. This study assessed first-line persistence and healthcare costs of HIV-1 in patients by treatment line and CD4 cell count. Methods: MarketScan Commercial Claims and Encounters Database (2007-2011) and Lab Database (2007-2010) were used to construct two HIV-1 cohorts: 1) newly treated HIV-1-infected patients with >= 6 months' continuous enrollment prior to first third-agent drug claim (Newly Treated Cohort) and 2) CD4 cell count test results (CD4 Measurements Cohort). All patients were >= 18 years old and without hepatitis co-infection. The Kaplan-Meier method was used to measure treatment switch rates. Generalized linear models (gamma distribution, log link) were used to compare healthcare costs by treatment line and CD4 cell count controlling for potential confounders. Results: Newly treated patients (n = 8,617) had mean age of 41, 82% were male, and 20% had experienced AIDS-defining events at baseline. Over 20% of newly treated patients switched initial treatment regimen within 2 years. Average unadjusted (and covariate-adjusted) total healthcare cost/year was $33,674 ($28,861) for first-line, $39,191 ($35,805) for second-line, and $39,882 ($40,804) for third-line treatment. Covariate-adjusted costs of care on second-and third-line treatments were significantly more expensive than first-line treatment (24% [p<0.001] and 41% [p=0.006] higher, respectively). The CD4 Measurements Cohort included 803 CD4 measurements (mean age 49, 76% male, 8% experienced an AIDS-defining event). Costs associated with CD4 measurements <100 cells/mu L were 92% higher than those with >350 cells/mu L (p<0.001). For higher CD4 cell counts, the majority of expenditures were for antiretrovirals (64% of total for CD4 > 350 cells/mu L). Conclusions: Despite modern advances in antiretroviral therapy and medical care, direct medical costs of HIV-1-infected patients increase after treatment switch and with lower CD4 counts, consistent with previous costing studies.