Injuries/Violence
easuring child maltreatment-related hospitalizations and emergency room visits across the ICD-9-CM to ICD-10-CM transition: Comparison of three approaches Kriszta Farkas* Kriszta Farkas Farkas Farkas Farkas Farkas Farkas Farkas University of Minnesota
Child Protective Services reports are a widely used measure of child maltreatment, despite many limitations. Hospital data on conditions indicative of maltreatment may be a complementary surveillance source. International Classifications of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes suggestive of maltreatment have been identified; however, the 2015 transition to ICD-10-CM requires crosswalks to capture incidents post-transition. We compared three crosswalk approaches using Centers for Medicare & Medicaid Services General Equivalence Maps: simple forward mapping (“forward”), forward and backward mapping (“forward-backward”), and multi-stage mapping (“multistage”), each varying in comprehensiveness and complexity. Validated ICD-9-CM codes for conditions indicative of child physical abuse and neglect were mapped to ICD-10-CM via each approach. We reviewed ICD-10-CM codes for accuracy, summarized differences across the approaches, and developed a strategy to improve comparability across the transition. We applied the crosswalks to California-wide hospital inpatient and emergency room data from 2005-2019 in children <5 years old and examined trends over the transition. Forward-backward mapping combined with exclusions identified by multistage mapping was the strongest approach. In comparison, forward mapping missed many valid ICD-10-CM codes, often only mapping broad codes. In contrast, multistage mapped many additional ICD-10-CM codes for conditions not of interest but was useful for identifying co-occurring ICD-10-CM exclusion codes needed to isolate the original ICD-9-CM conditions. Application of the final crosswalk resulted in consistent trends in California over the transition. Forward-backward combined with multistage mapping allows for accurate surveillance of child maltreatment in hospital data over the ICD transition; this approach may be useful in other applications.
