Objectives: To compare the abilities of six validated comorbidity indices (Charlson index, cumulative illness rating scale [CIRS], index of coexistent diseases, Kaplan scale, geriatrics index of comorbidity [GIC], and chronic disease score) to predict adverse hospitalization outcomes (death during hospitalization, length of stay, and institutionalization).
Study design and setting: Prospective cohort of 444 elderly inpatients (mean age 85.3) was randomly selected from Geneva geriatric hospital.
Results: In univariate analyses, GIC was the best predictor for all outcomes. The risk of death was 30 times higher and the risk of prolonged hospitalization and being institutionalized was eight to nine times higher in patients with scores of class 3 or 4. In adjusted logistic regression models, GIC remained the best predictor of death during hospitalization. Higher GIC scores accounted for 25% of the variance of this outcome, with mortality rates differing by a factor of four between the highest and the lowest scores. CIRS was a strong predictor of a prolonged hospital stay and institutionalization, accounting for 10% of the variance of these outcomes.
Conclusion: GIC was the most accurate predictor of death during hospitalization. CIRS could be used to select elderly patients at admission as an indicator of improvement at discharge.