A comparison between a SNOMED CT problem list and the ICD-10-CM/PCS HIPAA code sets

In 2013 the United States will convert from the use of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) to the use of the International Classification of Diseases, Tenth Revision, Clinical Modification/Procedure Coding System (ICD-10-CM/PCS). This study compares the approximately 5,000 terms in the July 2009 Clinical Observations Recording and Encoding (CORE) Problem List subset of the Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT) terminology produced by the National Library of Medicine with terms found in the January 2009 versions of ICD-10-CM/PCS. The comparison was done by a single individual and used the internally defined concepts of "Exact," "Inexact," "Model" (one SNOMED CT term to many ICD-10-CM/PCS terms), "Not Elsewhere Classified," "Not Otherwise Specified," "Synonym," and "Not Found" to classify the CORE Problem List terms according to the quality of the match. Among the CORE Problem List terms, 6.0 percent were not found in ICD-10-CM/PCS, and 69.1 percent had equivalent ICD-10-CM/PCS terms. The 13.0 percent of terms classified as "Inexact" could also be used directly assuming some acceptable loss of clinical precision. The 11.9 percent of terms classified as "Model" represent differences that require rule-based mapping. The results of this study suggest that ICD-10-CM/PCS meets the intended design goal of increased clinical precision but studies are needed to precisely define the depth of coverage.