Cost-effectiveness analysis of HLA-B*5701 typing in the prevention of hypersensitivity to abacavir in HIV+ patients in Spain

Introduction 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 6 months. 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 (AU)

Introducción Aproximadamente el 4–8% de los pacientes con VIH-1 tratados con abacavir presentan una reacción de hipersensibilidad (RHS). Diversos estudios han mostrado que existe una asociación directa entre el antígeno leucocitario humano (HLA)-B*5701 y la RHS a abacavir. El objetivo del presente estudio ha sido analizar si la realización sistemática del test HLA-B*5701 para prevenir la RHS en los pacientes tratados con abacavir es una opción coste-efectiva para el Sistema Nacional de Salud (SNS) español. Métodos Se realizó un modelo analítico de decisiones mediante un modelo de árbol de decisión para simular una cohorte de 1.000 pacientes con VIH en el que se comparó si la realización del test HLA-B*5701 para prevenir la RHS al tratamiento con abacavir era una opción coste-efectiva versus no realizar el test. Los parámetros introducidos en el modelo así como el uso de recursos sanitarios en caso de que el paciente desarrollase una RHS provenían del estudio PREDICT-1 y de la opinión de expertos clínicos. El resultado principal del studio fue el coste incremental por RHS evitada. El horizonte temporal del análisis fue de 6 meses. Todos los costes se expresaron en euros del año 2008.Resultados El análisis demostró que los costes sanitarios directos totales por paciente fueron 1.344 € y 1.322 € al realizar o no el test HLA-B*5701, respectivamente, evitando unos 36 casos de RHS por cada 1.000 pacientes cribados. Estos resultados dieron lugar a una razón de coste por RHS evitada de 630 €. El análisis de sensibilidad mostró que los resultados fueron sensibles al coste del test produciendo desde un ahorro económico de 102 € hasta una razón coste-efectividad de 4.234 €. Conclusiones (..) (AU)

Cost-effectiveness analysis of HLA-B*5701 typing in the prevention of hypersensitivity to abacavir in HIV+ patients in Spain.

INTRODUCTION: 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.