Validation and adaptation of the Charlson Comorbidity Index using administrative data from the Colombian health system: retrospective cohort study

Objective: To validate the Charlson Comorbidity Index (CCI) for the Colombian population using administrative databases from the health insurance system.

Design: Retrospective cohort study.

Setting: Database reports of events related to services that insurers provided (Health Promoter Enterprises, EPS in Spanish) in the Colombian health system, which covered 22.19 million residents in 2016.

Participants: The study cohort comprised 3 849 849 patients aged 18 years and up admitted to the Colombian hospitals between 1 January and 31 December 2016.

Primary outcome: The study aimed to gauge the CCI's predictive value for mortality by comparing the calibration and discrimination of three different versions of the index, with mortality information obtained from death certificates, including date of death and diagnoses associated with cause of death. Follow-up was conducted for at least 1 year.

Results: Altogether, 46 429 patients died within 1 year (1.21%). Discriminatory power in predicting 1-year mortality was calculated for three versions of the ICC. In the original CCI model, the area under the Receiver operating characteristic (ROC) curve was 0.906 (95% CI (0.906 to 0.907), p<0.001). In the version for Colombia, it was 0.908 (95% CI (0.908 to 0.909), p<0.001) and for the new model it was 0.909 (95% CI (0.908 to 0.910), p<0.001).

Conclusions: Adapting the CCI based on the 14 predictive variables of the new model resulted in an adequate predictive value for 1-year mortality in patients who were hospitalised for all causes. These findings support the use of the modified CCI in the Colombian population.