Accuracy of Diagnostic Codes for Identifying Brief Resolved Unexplained Events.

OBJECTIVES: To evaluate International Classification of Diseases, 10th Revision (ICD-10) coding strategies for the identification of patients with a brief resolved unexplained event (BRUE). METHODS: Multicenter retrospective cohort study, including patients aged <1 year with an emergency department (ED) visit between October 1, 2015, and September 30, 2018, and an ICD-10 code for the following: (1) BRUE; (2) characteristics of BRUE; (3) serious underlying diagnoses presenting as a BRUE; and (4) nonserious diagnoses presenting as a BRUE. Sixteen algorithms were developed by using various combinations of these 4 groups of ICD-10 codes. Manual chart review was used to assess the performance of these ICD-10 algorithms for the identification of (1) patients presenting to an ED who met the American Academy of Pediatrics clinical definition for a BRUE and (2) the subset of these patients discharged from the ED or hospital without an explanation for the BRUE. RESULTS: Of 4512 records reviewed, 1646 (36.5%) of these patients met the American Academy of Pediatrics criteria for BRUE on ED presentation, 1016 (61.7%) were hospitalized, and 959 (58.3%) had no explanation on discharge. Among ED discharges, the BRUE ICD-10 code alone was optimal for case ascertainment (sensitivity: 89.8% to 92.8%; positive predictive value: 51.7% to 72.0%). For hospitalized patients, ICD-10 codes related to the clinical characteristics of BRUE are preferred (specificity 93.2%, positive predictive value 32.7% to 46.3%). CONCLUSIONS: The BRUE ICD-10 code and/or the diagnostic codes for the characteristics of BRUE are recommended, but the choice between approaches depends on the investigative purpose and the specific BRUE population and setting of interest.