Objective: To identity prognostic factors associated with survival time in HIV-infected patients with advanced immunodeficiency.
Design: Prospective cohort study.
Participants: A total of 1284 HIV-infected patients with serial CD4 count measurements and at least one CD4 cell count < or = 50 x 10(6)/I (CD4 < or = 50).
Main outcome measure: Survival from initial CD4 cell count < or = 50 x 10(6)/l.
Results: The median survival from initial CD4 < or = 50 x 10(6)/l was 17.1 months. The risk of death increased by 2% 195% confidence interval (Cl), 1-31 for each year of age, by 10% (95% Cl, 3-16) for each 10 x 10(6)/l decrease in CD4 count, and by 14% (95% Cl, 9-18) for each 1 g/dl decrease in haemoglobin level. Compared to AIDS-free patients with CD4 < or = 50 x 10(6) cells/l, the risk of dying was 1.5-fold (95% Cl, 1.2-1.9) that of patients who had an AIDS diagnosis for fewer than 3 months prior to CD4 < or = 50, 1.8-fold for patients with an AIDS diagnosis for 4-11 months prior to CD4 < or = 50, and twice that of patients with AIDS for > or = 12 months prior to CD4 < or = 50. The risk of dying for patients whose rate of CD4 cell decline was > 40 x 10(6)/l per 6 months was 1.7-fold (95% Cl, 1.3-2.3) that of patients with an average CD4 cell loss < 40 x 10(6)/l per 6 months, after adjusting for age, haemoglobin and duration of AIDS prior to CD4 < or = 50 x 10(6) cells/l. A prognostic score was developed from the final multivariate model, based on age at CD4 < or = 50, haemoglobin at CD4 < or = 50, duration of AIDS and rate of CD4 decline prior to CD4 < or = 50.
Conclusions: Routinely available clinical and laboratory data including haemoglobin level, rate of CD4 decline and duration of AIDS can be readily translated into a prognostic score and then used to predict the survival experience of an HIV-infected patient with advanced immunodeficiency.