Comorbidity Acquired before HIV Diagnosis and Mortality in HIV-infected and Uninfected Persons: A Danish population-based cohort study

BACKGROUND:: We aimed to estimate the impact of comorbidity acquired before HIV diagnosis on mortality in HIV-infected individuals METHODS:: This cohort study compared two different cohorts. The prospective population-based nationwide observational Danish HIV Cohort Study was used to compare all adults diagnosed with HIV in Denmark from 1997 with a matched general population cohort. Comorbidity history was ascertained from the Danish National Patient Registry and vital statistics obtained from Denmark's Civil Registration System. Cox regression was used to estimate impact of Charlson Comorbidity Index (CCI) and hepatitis C virus coinfection (HCV) on mortality, and Population Attributable Risk to assess the proportional impact of comorbidity on mortality. RESULTS:: CCI comorbidity was present before HIV diagnosis in 11.3% of 1,638 persons with HIV, and in 8.0% of 156,506 persons in the general population. The risk of death in HIV patients with at least one CCI point was 1.84 times higher than in those with no CCI points (adjusted mortality rate ratio, 95% confidence interval: 1.32-2.57). The annual risk of dying for HIV patients vs general population with 0, 1, 2, and 3+ CCI points was 1.70% (1.44-2.00) vs 0.27% (0.26-0.28), 4.37% (3.01-6.32) vs 1.36% (1.26-1.47), 8.06% (4.94-13.16) vs 2.44% (2.22-2.68), and 10.15% (5.08-20.30) vs 5.84% (5.19-6.58), respectively. Comorbidity acquired before HIV, HCV, and background mortality accounted for 45% of total mortality in the HIV-infected population. CONCLUSIONS:: Almost half of deaths in persons diagnosed with HIV in a health care setting with free access to HAART stemmed from factors unrelated to HIV disease.