Economic evaluation of HIV treatments: The I.CO.N.A. cohort study

Objective: To describe the changes in costs of care for HIV-positive patients in Italy after the spread of antiretroviral combination therapies (HAART). Methods: Five thousand four hundred and twenty-two patients from the I.CO.N.A. (Italian Cohort Naive Antiretrovirals) study were followed between 1997 and 2002. Costs included antiretroviral therapies (ART), hospital admissions, prophylaxis, and main laboratory examinations. The perspective was that of the National Health Service. Results: Admission costs per person-year decreased from 2148 euro in 1997 to 256 in 2002, while the average annual costs of ART increased from 2145 to 3149 euro (1997 prices). From 1997 to1999, ART costs increased from 42.3 to 85.9% of the total, while admission costs decreased from 42.3 to 7.0% and prophylaxis from 7.3 to 1.7%. The breakdown of ART costs shows how dual therapies decreased over time in favor of HAART, falling from 26.8% in 1997 to 5.9% in 2002. Patients with fewer than five treatment switches had the lowest costs distributions over the entire observation period. Conclusions: From 1997 to 2002 inpatient costs progressively decreased in favor of antiretroviral therapy. Annual average costs per patient decreased, while total direct costs increased over time: health resources, initially concentrated on hospitalized patients were then distributed over a growing number of subjects.