Comparison of comorbidity classification methods for predicting outcomes in a population-based cohort of adults with human immunodeficiency virus infection

Ann Epidemiol. 2014 Jul;24(7):532-7. doi: 10.1016/j.annepidem.2014.04.002. Epub 2014 Apr 18.


Purpose: We compared the John's Hopkins' Aggregated Diagnosis Groups (ADGs), which are derived using inpatient and outpatient records, with the hospital record-derived Charlson and Elixhauser comorbidity indices for predicting outcomes in human immunodeficiency virus (HIV)-infected patients.

Methods: We used a validated algorithm to identify HIV-infected adults (n = 14,313) in Ontario, Canada, and randomly divided the sample into derivation and validation samples 100 times. The primary outcome was all-cause mortality within 1 year, and secondary outcomes included hospital admission and all-cause mortality within 1-2 years.

Results: The ADG, Elixhauser, and Charlson methods had comparable discriminative performance for predicting 1-year mortality, with median c-statistics of 0.785, 0.767, and 0.788, respectively, across the 100 validation samples. All methods had lower predictive accuracy for all-cause mortality within 1-2 years. For hospital admission, the ADG method had greater discriminative performance than either the Elixhauser or Charlson methods, with median c-statistics of 0.727, 0.678, and 0.668, respectively. All models displayed poor calibration for each outcome.

Conclusions: In patients with HIV, the ADG, Charlson, and Elixhauser methods are comparable for predicting 1-year mortality. However, poor calibration limits the use of these methods for provider profiling and clinical application.

Keywords: Comorbidity; Databases; Diagnosis-related groups; Factual; HIV; Logistic models; Predictive value of tests; ROC curve; Risk adjustment.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Canada / epidemiology
  • Cause of Death
  • Comorbidity*
  • Databases, Factual
  • Diagnosis-Related Groups*
  • Female
  • HIV Infections / diagnosis*
  • HIV Infections / mortality
  • Hospital Mortality*
  • Humans
  • Logistic Models
  • Middle Aged
  • Ontario
  • Predictive Value of Tests*
  • ROC Curve
  • Residence Characteristics
  • Risk Assessment / methods
  • Risk Assessment / standards*
  • Time Factors
  • Young Adult