Charlson Comorbidity Index

The Charlson Comorbidity index is a method of classifying prognostic comorbidity in longitudinal studies.

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 medical conditions of comorbidity some of which contain subcategories of diseases related to the primary category. For a list of all diagnosis applicable that we use go to: Charlson Comorbid Diagnosis].

The Charlson 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.

Backgrond / further info

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

Article related to Charlson

Article: An electronic application for rapidly calculating Charlson comorbidity score. Article with link to a comorbid score calculator developed in MS Excel using a macro.

• Copy of this calculator can be found: X:\CCMDB_ADMIN_DATABASE\Charlson_Comorbids\comorbid calculator