A simple scoring system predicted clinical progression in HIV patients receiving highly active antiretroviral therapy.

Patients 2027 patients (median age 37 y) formed the derivation set: inception cohort of participants in the EuroSIDA study who were > 16 years of age and had started a protease inhibitor or non-nucleoside reverse-transcriptase inhibitor as part of a HAART antiretroviral regimen and had CD4 cell counts and viral loads measured within 6 months before starting HAART and > 1 measurement after starting HAART. 2 cohorts of patients formed the validation set: 1946 patients in the EuroSIDA study who started HAART before recruitment to the study and 1442 patients from a clinic in Barcelona who had previously started HAART.