SEER-Medicare: Calculation of Comorbidity Weights

Macros to calculate Charlson comorbidity weights are provided to assist investigators with their analysis. Over the years NCI has evaluated the codes included in the calculation of comorbidity based on claims data. Currently, there are two NCI macros that use different weights to calculate Charlson comorbidity, see below. Researchers must decide which Charlson comorbidity macro to use: the original macro, which was developed by NCI in 2000, or the current version, which was initially developed in 2014. More details on the comparability of the two comorbidity macros can be found here.

NCI does not accept responsibility for the completeness or accuracy of the codes and weights used in the macros. Investigators may modify the macros if they wish to include different diagnosis codes or condition weights.