Comparing costs and effectiveness of different starting points for highly active antiretroviral therapy in HIV-positive patients: Evidence from the ICONA cohort

Abstract

We evaluated the costs and effectiveness of starting highly active antiretroviral therapy (HAART) at different points during the course of HIV infection, defined on the basis of CD4 T-lymphocytes counts. The study considered 3,250 HAART-naive patients of the Italian Cohort Naive Antiretrovirals (ICONA), enrolled and followed between 1997 and 2002. In correspondence to the thresholds of 500,350, and 200 CD4 cells/mm3, we selected immediate and deferred groups accounting for lead-time bias. The effects of immediate vs. deferred treatment on AIDS-free survival and direct health costs were estimated stratifying on the propensity score of immediate HAART initiation. The incremental cost-effectiveness ratio (ICER) and the cost-effectiveness acceptability curve were also obtained. Although immediate HAART initiation did not affect incidence AIDS and death at high CD4 levels, starting HAART with 200-349 CD4 cells/mm3 rather than deferring it below 200 CD4 cells/mm3, proved to be cost-effective. © Springer Medizin Verlag 2006.