Comparison of crosswalk methods for translating ICD-9 to ICD-10 diagnosis codes for child maltreatment

Background: A validated source of International Classification of Disease (1CD) 10th revision diagnostic codes to identify child maltreatment has not been developed. Such a reference would be essential for the practical purposes of administrative data-based research and public health surveillance.Objective: To evaluate the validity of diagnosis code classifications for child maltreatment following conversion from ICD 9th edition, clinical modification (ICD-9-CM) to 10th revision. Participants and setting: Children receiving inpatient or emergency medical care in the United States with ICD-9-CM/ICD-10-CM diagnosis codes for child maltreatment, identified using two large multicenter hospital-based datasets.Methods: We evaluated the performance of general equivalence mappings (GEMs) and network based mappings for previously-validated ICD-9-CM diagnosis codes for child maltreatment in the 2013-2014 PHIS and 2012 KID and resulting ICD-10-CM codes in the 2018-2019 PHIS and 2016 KID datasets.Results: Of 56 previously-validated ICD-9-CM diagnoses, GEMs identified 15 with a similar proportion of diagnosed children in the KID ICD-9-CM and ICD-10 eras and 14 diagnoses in PHIS. Network-based mapping identified 18 diagnoses with similar proportions in the KID datasets, and 13 diagnoses in PHIS. For six diagnoses, the proportion of children identified in the ICD-10 era using network-based mapping was more than ten times the proportion identified in the ICD-9-CM era.Conclusion: Neither crosswalk method provided consistently reliable conversions, due to both crosswalk methodology and changes introduced by the ICD 10th revision. These findings highlight the need for independent construction and validation of ICD-10-based definitions of child maltreatment as a precursor to administrative data-based research and public health surveillance.

Automated summary

This study evaluated the validity of converting ICD-9-CM diagnosis codes to the 10th revision for identifying child maltreatment. The results showed that the current conversion methods are not consistently reliable, highlighting the need for independent construction and validation of ICD-10-based definitions of child maltreatment.