Title: Comparison of the Performance of a Newly Developed Risk Adjustment Tool, Diagnostic Items, with the Charlson Comorbidity Method in Predicting Hospital Mortality

Introduction and Aim: This study aims to assess the performance of a newly developed diagnostic classification system for costs, Diagnostic Items (DXIs) as a risk adjustment method in predicting mortalities. We compared the model performance between DXIs and widely used Charlson comorbidity method, using admission claims data.