Trends in ICD-10-CM–Coded Administrative Datasets for Injury Surveillance and Research

OBJECTIVES: Accurate injury surveillance depends on data quality in administrative datasets created for billing and reimbursement. Significant effort has been devoted to testing the ability of candidate injury case definitions to identify injury cases accurately in these datasets. We used interviews with experienced coders, informed by a review of the current literature, to identify three clinical coding trends that may affect the consistency of surveillance data: “clinical documentation improvement or clinical documentation integrity” (CDI), coding by treating clinicians, and certain electronic health record features. METHODS: An extensive literature review informed interviews with coding experts to identify potential issues in coding practice. To determine whether physician coding was associated with information loss, we analyzed data from two hospitals serving the same geographic area. One hospital had used physician coding of emergency department data for the past decade; the other used professional coders. We compared the proportion of emergency department records missing external cause of injury codes and assessed the variation for statistical significance. RESULTS: CDI audits review patient records to ensure that billing information includes every relevant International Classification of Diseases, Tenth Revision, Clinical Modification code. This approach has increased payment rates awarded to Medicare Advantage plans because additional codes increase the patient acuity level and case mix index. The impact of CDI audits on injury data needs further investigation. The pilot analysis addressing information loss with physician coding found a higher level of external cause coding with clinician self-coding, possibly because of the coding software. Finally, widespread “copy and paste” in patient electronic health records has the potential to increase reported injuries. CONCLUSIONS: Injury surveillance relies on billing and reimbursement records. Financial motivations may interfere with the consistency of surveillance findings and mislead injury epidemiologists. Further investigation is essential to ensure the integrity of surveillance findings.