HEALTHCARE COSTS OF MEDICALLY-ATTENDED ADVERSE EFFECTS IN MEDICAID HIV PATIENTS ON ATAZANAVIR- AND DARUNAVIR-BASED ANTIRETROVIRAL THERAPY

  

Purpose : Antiretroviral therapy (ART) adverse effects (AEs) can have a substantial impact on HIV patients' quality of life, healthcare resource utilization and adherence and persistence to ART. Atazanavir and darunavir are currently the only protease inhibitors preferred in first-line ART regimens in the Department of Health and Human Services (DHHS) antiretroviral treatment guidelines.  To date, atazanavir has not been compared to darunavir in either a clinical trial or the “real world” setting of routine care. This study is the first to compare the healthcare costs of medically-attended AEs in atazanavir- and darunavir-based ART among U.S. Medicaid patients receiving routine care.   

Method : Retrospective study using Medicaid administrative healthcare claims from 15 States. Subjects were HIV patients aged 18–64 years initiating atazanavir- or darunavir-based ART from 1/1/2003—7/1/2010, with continuous enrollment for 6 months before (baseline) and 6 months after (evaluation period) ART initiation, and ≥1 evaluation period medical claim. Outcomes were per-patient-per-month (PPPM) healthcare costs of medically-attended (ICD-9-CM-coded or treated) AEs during the evaluation period. Five AEs were chosen for study from those listed within the DHHS antiretroviral treatment guidelines as being specific to atazanavir and darunavir: gastrointestinal; lipid abnormalities; diabetes/hyperglycemia; rash; jaundice.  All-cause healthcare costs were also examined. Atazanavir and darunavir patients were propensity score matched (ratio=3:1, nearest neighbor with calipers technique) using demographic and clinical covariates. Multivariable models adjusted for covariates lacking post-match statistical balance.   

Result : Propensity-matched study sample included 1,848 atazanavir and 616 darunavir patients; mean age 41 years, 50% female, 69% black. Table displays unadjusted PPPM healthcare costs and adjusted PPPM healthcare cost differences (darunavir minus atazanavir). Jaundice occurred too infrequently to support multivariable modeling (11 instances in atazanavir, 1 in darunavir).   

Conclusion : Compared to atazanavir patients, patients treated with darunavir incurred higher adjusted healthcare costs for medically-attended AEs as well as higher all-cause healthcare costs, the difference being statistically significant in the latter case.

	Atazanavir unadjusted	Darunavir unadjusted	Adjusted difference (Darunavir minus Atazanavir)
PPPM healthcare costs $, Mean [SD]
Gastrointestinal	$38 [$387]	$73 [$382]	$43	p=0.132
Lipid abnormalities	$14 [$544]	$0 [$4]	$3	p=0.879
Diabetes/hyperglycemia	$28 [$396]	$27 [$297]	$13	p=0.693
Rash	$96 [$1,253]	$62 [$518]	$0	p=0.760
Jaundice	$6 [$80]	$5 [$25]	n/a	n/a
All-cause healthcare	$3,879 [$6,635]	$5,354 [$8,127]	$1,086	p<0.001