A prospective cost-consequence analysis of adding lamivudine to zidovudine-containing antiretroviral treatment regimens for HIV infection in the US.

BACKGROUND Healthcare resource use data were collected for 1 year as part of the CAESAR (Canada, Australia, Europe, South Africa) clinical trial, which evaluated the effect of adding lamivudine to treatment regimens containing zidovudine in patients with HIV infection. This study showed that lamivudine-containing regimens reduced HIV disease progression to AIDS or death, in addition to significantly reducing the number of hospital stays, unscheduled outpatient visits, and medications for HIV-related illness. Estimates of US unit costs for each healthcare service were derived from nationally representative data sources, and were used to determine the costs of treatment during the trial period for the treatment and control groups. RESULTS A cost-consequence analysis showed that, in addition to the health benefits associated with the lamivudine regimen, costs for treating HIV-related illness and adverse events were lower with the lamivudine regimen. The average decrease in costs per patient for the 1-year period ranged from $US1922 to $US2645, depending on the data source used to estimate hospital length of stay. The incremental cost of lamivudine therapy for the 1-year period was $US2293. The estimated difference in total costs for the 2 treatment regimens thus ranged from an increase of $US371 to a cost saving of $US353. CONCLUSIONS Our findings indicate that treatments which slow the progression of HIV infection have the potential to reduce the monthly costs associated with HIV-related illness and adverse events during the time period that progression is slowed.