Estimating the proportion of patients infected with HIV who will die of comorbid diseases

Abstract

Purpose: Effective antiretroviral therapies have improved the prognosis for patients infected with the human immunodeficiency virus (HIV). We aimed to estimate the likelihood that HIV-infected patients would die of comorbid disease.

Methods: A probabilistic simulation of antiretroviral-naïve HIV-infected patients in the United States was calibrated with data from an observational cohort (N = 3545) and validated with data from a separate patient cohort (N = 12574). The simulation explicitly represents the 2 main determinants of treatment failure and subsequent death from HIV-related causes: nonadherence to combination therapy and accumulation of phenotypic resistance to combination therapy. The likelihood of deaths not directly attributable to HIV was estimated from the Collaborations in HIV Outcomes Research-US (CHORUS) cohort.

Results: For patients with newly diagnosed HIV infections, CD4 counts of 500 cells/mm3, and viral loads of 10000 copies/mL, the median estimated survival was 26.8 years for 30-year-olds, 24.4 years for 40-year-olds and 14.6 years for 50-year-olds. The proportion of deaths not directly attributable to HIV was 36% for 30-year-olds, 53% for 40-year-olds, and 72% for 50-year-olds. For patients with characteristics similar to CHORUS participants, the median estimated survival approached 20.4 years, the mean age at death approached 60.4 years, and 41% died of illnesses not directly attributable to HIV. These estimates of non-HIV mortality were likely conservative.

Conclusion: As HIV-infected patients live longer, our results suggest they will experience increasing mortality from causes not directly attributable to HIV. The projected risk from comorbid disease has clinical and policy implications for future delivery of care to HIV-infected patients.