Conversion of the Agency for Healthcare Research and Quality's Quality Indicators from ICD-9-CM to ICD-10-CM/PCS: The Process, Results, and Implications for Users

On October 1, 2015, the U.S. Department of Health and Human Services began requiring hospitals to report diagnoses and procedures using the International Classification of Diseases, 10th Revision, Clinical Modification [...]
Objective. To convert the Agency for Healthcare Research and Quality's (AHRQ) Quality Indicators (QIs) from International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) specifications to ICD, 10th Revision, Clinical Modification and Procedure Classification System (ICD-10-CM/PCS) specifications. Data Sources. ICD-9-CM and ICD-10-CM/PCS classifications, General Equivalence Maps (GEMs). Study Design. We convened 77 clinicians and coders to evaluate ICD-10-CM/PCS codes mapped from ICD-9-CM using automated GEMs. We reviewed codes to develop "legacy" specifications resembling those in ICD-9-CM and "enhanced" specifications addressing enhanced capabilities of ICD-10-CM/PCS. Data Collection/Extraction Methods. We tabulated the numbers of mapped codes, added nonmapped codes, and deleted mapped codes to achieve the specifications. Principal Findings. Of 212 clinical concepts (sets of codes) that comprise the QI specifications, we either added nonmapped codes to or deleted mapped codes from 115 (54 percent). The legacy and enhanced specifications differed for 46 sets (22 percent), affecting 67 of the 101 QIs (66 percent). Occasionally, concepts that defied conversion required reformulation of indicators. Conclusions. Converting the AHRQ QIs to ICD-10-CM/PCS required a detailed, thorough process beyond automated mapping of codes. Differences between the legacy and enhanced versions of the QIs are frequently minor but sometimes substantive. Key Words. Quality indicators, administrative data, ICD-9-CM, ICD-10-CM/PCS, GEMs