Effect of HAART on Health Status and Hospital Costs of Severe HIV-Infected Patients: A Modeling Approach

Abstract

Purpose: The purpose of this study was to assess the impact of highly active antiretroviral therapy (HAART) on health status and hospital costs in severe HIV-infected patients who were followed in a French hospital. Method: The first 500 patients who received HAART, with CD4 + cell count below 250/mm³, were considered. Evolution of the distribution of patients among different health states, including death, was modeled through a continuous time Markov model. Hospital financial charges and antiretroviral treatment costs were computed. Health states defined by both CD4 counts and viral load were used to show clinical changes in the patient population over a 14-month period after HAART initiation. The economic impact of HAART initiation was assessed using a simplified model based on CD4 counts only over two 14-month periods, before and after initiation. Results: Between day 0 and month 14, the proportion of patients in the least severe state (CD4 + >100/mm³ and viral load<500 copies/mL) increased from 1% to 50%, and the proportion with more than 100 CD4 + cells/mm³ increased from 17% to 80%. Antiretroviral treatments amounted to Fr 2,141 per patient-month before HAART initiation and to Fr 3,093 after. Conversely, hospital charges fell from Fr 5,138 per patient-month to Fr 3,136. Conclusion: Our model gives a representation of the effect of HAART on (1) the improvement of patients’ health status, (2) the increase of treatment costs, and (3) the reduction of hospital financial charge. Important savings in hospital charges can compensate for the extra cost associated with the initiation of HAART.

Keywords:

• HAART
• cost
• Markov model