Comparative incidence and health care costs of medically attended adverse effects among U.S. Medicaid HIV patients on atazanavir- or darunavir-based antiretroviral therapy

Abstract

Objectives: This is the first study to compare the incidence and health care costs of medically attended adverse effects in atazanavir- and darunavir-based antiretroviral therapy (ART) among U.S. Medicaid patients receiving routine HIV care.

Methods: This was a retrospective study using Medicaid administrative health care claims from 15 states. Subjects were HIV patients aged 18 to 64 years initiating atazanavir- or darunavir-based ART from January 1, 2003, to July 1, 2010, with continuous enrollment for 6 months before (baseline) and 6 months after (evaluation period) ART initiation and 1 or more evaluation period medical claim. Outcomes were incidence and health care costs of the following medically attended (International Classification of Diseases, Ninth Revision, Clinical Modification-coded or treated) adverse effects during the evaluation period: gastrointestinal, lipid abnormalities, diabetes/hyperglycemia, rash, and jaundice. All-cause health care costs were also determined. Patients treated with atazanavir and darunavir were propensity score matched (ratio = 3:1) by using demographic and clinical covariates. Multivariable models adjusted for covariates lacking postmatch statistical balance.

Results: Propensity-matched study sample included 1848 atazanavir- and 616 darunavir-treated patients (mean age 41 years, 50% women, 69% black). Multivariable-adjusted hazard ratios (HRs) (for darunavir, reference = atazanavir) and per-patient-per-month health care cost differences (darunavir minus atazanavir) were as follows: gastrointestinal, HR = 1.25 (P = 0.04), $43 (P = 0.13); lipid abnormalities, HR = 1.38 (P = 0.07), $3 (P = 0.88); diabetes/hyperglycemia, HR = 0.84 (P = 0.55), $13 (P = 0.69); and rash, HR = 1.11 (P = 0.23), $0 (P = 0.76); all-cause health care costs were $1086 (P<0.001). Too few instances of jaundice (11 in atazanavir and 1 in darunavir) occurred to support multivariable modeling.

Conclusions: Medication tolerability can be critical to the success or failure of ART. Compared with darunavir-treated patients, atazanavir-treated patients had significantly fewer instances of medically attended gastrointestinal issues and more instances of jaundice and incurred significantly lower health care costs.