The short duration of antiretroviral drug regimen clinical trials does not allow for long-term economic and quality-of-life (QOL) evaluations of the various competing antiretroviral regimens. However, estimates of long-term outcome and cost differences can be obtained from a long-term model using surrogate marker data obtained from antiretroviral clinical trials, incorporating epidemiological and economic data, and data on current patterns of treatment. A team of investigators from the Medical University of South Carolina, Charleston, and Abbott Laboratories, Illinois, US, constructed a model to assess the long-term health outcomes and lifetime cost effectiveness of the fixed combination antiretroviral agent lopinavir/ritonavir, compared with nelfinavir, in treatment-naive patients. The results of the study were presented at the 5th Annual Congress of the International Society for Pharmacoeconomics and Outcomes Research, held in Rotterdam, The Netherlands, in November.