Charlson Comorbidity Index

The Charlson Index was developed in 1987 based on 1-year mortality data from internal medicine patients admitted to a single New York Hospital and was initially validated within a cohort of breast cancer patients. The index encompasses 19 medical conditions weighted 1–6 with total scores ranging from 0–37. In the development phase of the index, mortality for each disease was converted to a relative risk of death within 12 months. A weight was then assigned to each condition based on the relative risk (RR); for example, RR <1.2 = weight 0, RR ≥ 1.2<1.5 = weight 1, RR ≥ 1.5<2.5 = weight 2, RR ≥ 2.5<3.5 = weight 3, and for 2 conditions (metastatic solid tumor and AIDS) = weight 6. From the weighted conditions, a sum score can be tallied to yield the total comorbidity score.

See article: image or Charlson article, page 2. A PDF of the complete original article can be found on- X:\CCMDB_ADMIN_DATABASE\Charlson_Comorbids\OriginalCharlsonArticlePDF

Use of Charlson Comorbidity Index

• The number of comorbid conditions is used to provide an indication of health status and risk of death. The more comorbid conditions the higher risk for bad outcome.
• Comorbidity and their associated weights provide an overall comorbidity score to reflect the cumulative increased likihood of one year mortality.

• Use for MOST score for Medicine
• Use for APACHE II score for Critical Care

Charlson Comorbid Diagnosis

Contains 19 primary categories of comorbidity with a number of subcategories of diseases related to the primary category. For a list of all diagnosis used in each of these 19 categories go to: Charlson Comorbid Diagnosis].

The comorbid diagnosis codes have been mapped to the Critical Care/Medicine Diagnosis Coding Index which is stored in the S_AllDiagnoses list used in CCMDB.mdb.