Charlson Comorbidities Index

The Charlson Comorbidity Index (CCI) was developed and validated as a measure of 1-year mortality risk and burden of disease. 1, 2, 3, 4 To account for age being an independent predictor of mortality, a Combined Age-CCI (CA-CCI) score can be generated. 1, 2, 3 The CCI has been extensively used in clinical research to address the confounding influence of comorbidities, predict outcomes, standardise comorbidities abstracted from medical records or administrative databases and for self report of comorbidities. 1, 3, 5, 6, 7, 8, 9 In clinical practice, the CCI reduces comorbidities into a single numeric score that may assist health professionals with stratifying patients into subgroups based on disease severity, developing targeted models of care and resource allocation. 3, 8 CCI consists of 17 comorbidities, with two subcategories for diabetes and liver disease. 1, 2, 3 Comorbidities are weighted from 1 to 6 for mortality risk and disease severity, and then summed to form the total CCI score. 1, 2, 3 The CA-CCI is generated by adding 1 point to the CCI score for each decade of age over 40 years. 1, 2, 3 The CCI and CA-CCI require minimal training and are freely available for researchers and health professionals, with guidelines reported in Charlson et al. 1 To enable rapid electronic calculation of the CCI and CA-CCI, a Microsoft excel spreadsheet has been developed. 3 The CCI has been modified, with adaptations to comorbidities, administration and scoring. 3, 4, 5, 6, 7, 9 The Self Reported-CCI (SR-CCI) can be self-administered or performed as a 10-minute interview. 6, 7 The SR-CCI uses the same scoring algorithm as the CCI, except presence of liver disease is scored as 2 points.