Validation and Recalibration of Charlson and Elixhauser Comorbidity Indices Based on Data From a Japanese Insurance Claims Database

Abstract

In clinical research, comorbidities comprise important baseline variables that help researchers to understand patient profiles. Quantifying comorbidities is essential to determine their effect on various outcomes such as treatment selection, in-hospital death, length of hospitalization, and effect on long-term outcomes. The Charlson comorbidity index(CCI)was developed in the United States more than thirty years ago with the aim of predicting one-year mortality in hospitalized patients. In the CCI, statistical analysis of raw medical chart data was used to 薬剤疫学 Jpn J Pharmacoepidemiol, 24�2) July 2019:53