Identification of physical abuse-related hospitalizations in young children: Impact of the transition to ICD-10-CM coding

Background: Administrative healthcare databases are frequently used for child physical abuse (CPA)-related research and surveillance. In October 2015, the United States transitioned to the International Classification of Diseases, Clinical Modification-10th Revision (ICD-10-CM) coding regimen. ICD-10-CM expands coding related to CPA, including codes to differentiate suspected from confirmed CPA. Objective: This study examined the impact of the transition to ICD-10-CM coding on population-level trends in rates of hospitalizations coded for CPA. Participants and settings: Hospitalizations coded as related to CPA in children <5 years-of-age from 2010 to 2017 were identified across 19 Statewide Inpatient Databases. Methods: Interrupted time series analyses were used to assess the impact of the coding transition on hospitalizations coded for CPA, overall and by child race/ethnicity. Results: Of 9715 hospitalizations coded for CPA, 2797 (29%) occurred after the coding transition, including 51% coded for suspected CPA and 49% coded for confirmed CPA. There was a marginally-significant increase in the trend in CPA-related hospitalization after the coding transition among all children (0.09 per 100,000 children-per-quarter, p = 0.06), a significant increase in the trend among white children (0.15 per 100,000 children-per-quarter, p = 0.01), and no change among Black or Hispanic children. After the coding transition, hospitalizations coded for suspected CPA increased significantly overall (0.10 per 100,000 children-per-quarter, p < 0.001), and in particular among white children (0.12 per 100,000 children-per-quarter, p = 0.01) but not among Black or Hispanic children. Conclusions: The transition to ICD-10-CM differentially impacted trends in hospitalizations coded for CPA by child race/ethnicity. Further research is necessary to discern the reasons for these discrepancies.