Cost-effectiveness analysis of UGT1A1 genetic testing to inform antiretroviral prescribing in HIV disease.

Schackman BR, Haas DW, Becker JE, Berkowitz BK, Sax PE, Daar ES, Ribaudo HJ, Freedberg KA.

Source

Department of Public Health, Weill Cornell Medical College, New York, NY, USA. brs2006@med.cornell.edu.

Abstract

BACKGROUND:

Homozygosity for UGT1A1*28/*28 (Gilbert's variant) has been reported to be associated with atazanavir-associated hyperbilirubinemia and premature atazanavir discontinuation. We assessed the potential cost-effectiveness of UGT1A1 testing to inform choice of an initial protease inhibitor-containing regimen in antiretroviral therapy (ART)-naïve individuals.

METHODS:

We used the Cost-Effectiveness of Preventing AIDS Complications (CEPAC) computer simulation model to project quality-adjusted life years (QALYs) and lifetime costs (2009 US dollars) for atazanavir-based ART with or without UGT1A1 testing, using darunavir rather than atazanavir when indicated. We assumed UGT1A1-associated atazanavir discontinuation rates reported in the Swiss HIV Cohort Study, a *28/*28 frequency of 14.9%, equal efficacy and cost of atazanavir and darunavir, and genetic assay cost of $107. Sensitivity analyses varied these parameters and hyperbilirubinemia impact on quality of life and loss to follow-up (LTFU). Costs and QALYs were discounted at 3% annually.

RESULTS:

Initiating atazanavir-based ART at CD4 <500 0.49="0.49" 10="10" 16.02="16.02" an="an" and="and" average="average" by="by" cost-effective="cost-effective" cost.="cost." discounted="discounted" expectancy="expectancy" for="for" had="had" increased="increased" l="l" life="life" lifetime="lifetime" not="not" of="of" patients="patients" per="per" qalys="qalys" tested="tested" testing="testing" ugt1a1="ugt1a1" was="was" without="without">$100,000/QALY). Testing for UGT1A1 was cost-effective (<$100,000/QALY) if assay cost decreased to $10, or if avoiding hyperbilirubinemia by UGT1A1 testing reduced LTFU by 5%. If atazanavir and darunavir differed in cost or efficacy, testing for UGT1A1 was not cost-effective under any scenario.

CONCLUSIONS:

Testing for UGT1A1 may be cost-effective if assay cost is low and if testing improves retention in care, but only if the comparator ART regimens have the same drug cost and efficacy.