Prognosis of patients with HIV-1 infection starting antiretroviral therapy in sub-Saharan Africa: a collaborative analysis of scale-up programmes

Abstract

Background: Prognostic models have been developed for patients infected with HIV-1 who start combination antiretroviral therapy (ART) in high-income countries, but not for patients in sub-Saharan Africa. We developed two prognostic models to estimate the probability of death in patients starting ART in sub-Saharan Africa.

Methods: We analysed data for adult patients who started ART in four scale-up programmes in Côte d'Ivoire, South Africa, and Malawi from 2004 to 2007. Patients lost to follow-up in the first year were excluded. We used Weibull survival models to construct two prognostic models: one with CD4 cell count, clinical stage, bodyweight, age, and sex (CD4 count model); and one that replaced CD4 cell count with total lymphocyte count and severity of anaemia (total lymphocyte and haemoglobin model), because CD4 cell count is not routinely measured in many African ART programmes. Death from all causes in the first year of ART was the primary outcome.

Findings: 912 (8.2%) of 11 153 patients died in the first year of ART. 822 patients were lost to follow-up and not included in the main analysis; 10 331 patients were analysed. Mortality was strongly associated with high baseline CD4 cell count (>/=200 cells per muL vs <25; adjusted hazard ratio 0.21, 95% CI 0.17-0.27), WHO clinical stage (stages III-IV vs I-II; 3.45, 2.43-4.90), bodyweight (>/=60 kg vs <45 kg; 0.23, 0.18-0.30), and anaemia status (none vs severe: 0.27, 0.20-0.36). Other independent risk factors for mortality were low total lymphocyte count, advanced age, and male sex. Probability of death at 1 year ranged from 0.9% (95% CI 0.6-1.4) to 52.5% (43.8-61.7) with the CD4 model, and from 0.9% (0.5-1.4) to 59.6% (48.2-71.4) with the total lymphocyte and haemoglobin model. Both models accurately predict early mortality in patients starting ART in sub-Saharan Africa compared with observed data.

Interpretation: Prognostic models should be used to counsel patients, plan health services, and predict outcomes for patients with HIV-1 infection in sub-Saharan Africa.

Funding: US National Institute of Allergy And Infectious Diseases, Eunice Kennedy Shriver National Institute of Child Health and Human Development, and National Cancer Institute.

Figure 1

Kaplan-Meier curves of probability of death in patients starting antiretroviral therapy in sub-Saharan Africa 2004–2007, according to sex, age, baseline clinical stage, CD4 count, viral load, weight, degree of anaemia, and total lymphocyte count.

Figure 2

Cumulative mortality predicted from prognostic models compared to Kaplan-Meier curves of observed mortality for five prognostic groups of patients starting antiretroviral therapy in sub-Saharan Africa. Upper panel shows comparison with CD4 count model, lower panel with total lymphocyte count (TLC)/haemoglobin (Hb) model.

Figure 3

Cumulative mortality predicted from prognostic models compared to Kaplan-Meier curves of observed mortality for a group of patients at medium risk starting combination antiretroviral treatment in four programmes in sub-Saharan Africa. The upper panel shows the comparison with CD4 count model, the lower panel with total lymphocyte count/haemoglobin (TLC/Hb) model. Patients had the following characteristics: female, age<40, advanced disease stage, weight 50–59 kg and CD4 100–199 cells/μL or severe anaemia and TLC 800–1199/μL.