Economic analysis of initial HIV treatment - Efavirenz- versus indinavir-containing triple therapy

Objective: To compare the clinical and economic outcomes associated with tr iple therapy containing efavirenz or indinavir and 2 nucleoside reverse tra nscriptase inhibitors (NRTIs; zidovudine and lamivudine) in HIV-positive pa tients. Design and setting: An economic model based on viral load and CD4+ cell cou nts to predict long term outcomes such as progression to AIDS and AIDS-rela ted death was developed and then analysed using data from a randomised clin ical trial. Cost estimates from the healthcare system perspective were base d on data from 6 state, all-payor databases, the AIDS Cost and Services Uti lisation Study, and other literature. Analyses were carried out for time ho rizons between 5 and 15 years. Patients and interventions: HIV-positive patients with limited exposure to NRTIs. Initial regimens consisted of efavirenz or indinavir, each combined with 2 NRTIs. A maximum of 2 switches to other regimens was permitted. Main outcome measures and results: The efavirenz-containing triple therapy regimen was predicted to prolong survival at a savings of up to 10 923 US d ollars (1998 values) relative to initial therapy with the indinavir-contain ing regimen. Patients who receive efavirenz are expected to have 11% greate r survival at 5 years and fewer treatment failures (28 vs 52%, at 2 years). Overall, the economic and health benefits predicted for the efavirenz-cont aining regimen were robust to reasonable variation in key parameters. Conclusions: The superior clinical trial outcomes for efavirenz-containing regimens should translate into substantial economic and health benefits.