Cost-effectiveness analysis of HLA-B*5701 typing in the prevention of hypersensitivity to abacavir in HIV+ patients in Spain.
BACKGROUND
Approximately 4% to 8% of patients with HIV-1 treated with abacavir present a hypersensitivity reaction (HSR). Various studies have shown a direct association between human leukocyte antigen (HLA)-B*5701 and HSR to abacavir. The objective of this study was to analyze whether systematic HLA-B*5701 testing to prevent HSR in patients treated with abacavir is a cost-effective option for the Spanish National Health System.


METHODS
An analytical decision-making model was constructed as a decision tree model for a simulated cohort of 1000 HIV patients to evaluate whether HLA-B*5701 testing to prevent HSR to abacavir was cost effective compared with not performing the test. The parameters included in the model and the use of healthcare resources should the patient develop HSR were taken from the PREDICT-1 study and the opinion of clinical experts. The principal result obtained was the incremental cost per HSR avoided. The time horizon of the analysis was to 2 months [corrected] . All costs were expressed in 2008 Euros.


RESULTS
The analysis showed that the total direct healthcare costs per patient were €1344 and €1322 with and without HLA-B*5701 testing respectively, and that 36 cases of HSR were prevented per 1000 screened patients. These results yielded a cost per HSR avoided of €630. The sensitivity analysis showed that the results were sensitive to the cost of the test, with an economic saving of €102 or a cost-effectiveness ratio of €4234.


CONCLUSIONS
The model predicts that generalized use of the HLA-B*5701 test before prescribing abacavir in HIV+ patients could represent an economic saving or a limited additional cost for the National Health System which may be counterbalanced by the benefits in terms of a lower incidence of HSR.
Nieves Calatrava
Diana
D
Oblikue Consulting, Barcelona, Spain. diana.nieves@oblikue.com
Calle-Martín
Oscar de la
Ode L
Iribarren-Loyarte
José A
JA
Rivero-Román
Antonio
A
García-Bujalance
Laura
L
Pérez-Escolano
Isabel
I
Brosa-Riestra
Max
M
D019380:Anti-HIV Agents / Q000009:adverse effects*; D003362:Cost-Benefit Analysis; D015224:Dideoxynucleosides / Q000009:adverse effects*; D004342:Drug Hypersensitivity / Q000191:economics* / Q000276:immunology / Q000517:prevention & control*; D006679:HIV Seropositivity / Q000188:drug therapy*; D015235:HLA-B Antigens / Q000276:immunology; D006801:Humans; D018803:Models, Economic; D013030:Spain; D000099227:Abacavir
D019380:Anti-HIV Agents; D015224:Dideoxynucleosides; D015235:HLA-B Antigens; D000099227:Abacavir