1 The software was translated into ICD-10-CM prior to the availability of ICD-10-CM-coded data and released as a beta version. The Elixhauser Comorbidity Software was originally developed using ICD-9-CM diagnosis codes and diagnosis-related groups (DRGs) to identify comorbidities reported on adult inpatient discharge data. The Elixhauser Comorbidity Software Refined for ICD-10-CM is based on the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) diagnosis codes with indicators whether the diagnoses were present on admission (POA). The identified comorbidities co-exist at the time of hospitalization or outpatient encounter and were originally selected because they impacted resource allocation (e.g., length of stay or charges) and affect healthcare outcomes, such as in-hospital mortality and readmissions. The Elixhauser Comorbidity Software Refined for ICD-10-CM assigns data elements that identify 38 different pre-existing conditions based on secondary diagnoses (i.e., comorbidities) listed on hospital administrative data.
