Charlson Updated Index for Risk Adjustment in Hospital Discharge Quan et al. 2011 Updated Charlson Index & Score for Risk Adjustment in Hospital Discharge
Quan H, Li B, Couris CM, et al. Updating and validating the Charlson comorbidity index and score for risk adjustment in hospital discharge abstracts using data from 6 countries. Am J Epidemiol. 2011;173(6):676-82.