CharlsonKomorbiditätsindex

The Charlson Comorbidity Index (CCI) is a method for classifying prognostic comorbidity in longitudinal studies. Developed by Mary E. Charlson and colleagues in 1987, the index assigns weights to a set of 19 medical conditions that are associated with mortality risk. The weights, typically 1, 2, 3, or 6, are summed to produce a single comorbidity score that correlates with the probability of one-year mortality and other outcomes. Higher scores indicate greater predicted risk.

Calculation and adaptations: In its original form, the CCI requires chart review to identify present comorbidities and apply the corresponding weights. To facilitate use with administrative data, several adaptations have been proposed, notably the Deyo, Romano, and Quan versions, which map diagnoses to the index using ICD-9-CM or ICD-10 codes. An age-adjusted version adds points for patient age, usually one point per decade beyond age 50, to improve mortality prediction.

Usage: The CCI is widely used for risk adjustment in clinical studies, prognostication in various diseases, and comparative effectiveness research. It helps researchers account for baseline comorbidity when evaluating outcomes or comparing treatments and care settings.

Limitations: The index relies on accurate coding and may not fully reflect current clinical practice or all risk factors. The weights may not be equally valid across all populations, and the tool does not capture severity of each condition beyond its presence, nor non-mortality outcomes.