Specialty Consultations and Diagnostic Testing Accuracy After Brief Resolved Unexplained Events: A Multicenter Observational Study.

Objectives: Current BRUE guidelines focus on lower-risk infants (approximately 5%), leaving management strategies for the majority undefined. We aimed to evaluate the diagnostic yield and accuracy of tests and subspecialist consultations among all infants with BRUE.

Methods: In this retrospective cohort (2017-2021) across 11 Canadian hospitals, we included 1042 infants with BRUE. Records within 90 days of the index visit were reviewed to ascertain diagnostic testing and any newly identified underlying diagnoses. Diagnostic accuracy was evaluated by comparing test results to diagnoses confirmed or considered probable by care teams.

Results: Among 855 patients (82.1%) who underwent testing, 72 (8.4%) received explanatory diagnoses, and 554 (64.8%) had nonsignificant or incidental findings. Complete blood count (50.2%, N = 523) had low sensitivity (26.3%) and specificity (57.5%) for anemia and bacterial infections. Electrocardiograms (55.3%, N = 576) showed a sensitivity of 45.5% and specificity of 73.5%, while electroencephalograms (23.3%, N = 243) showed higher sensitivity (72.7%) and specificity (83.3%). Tests like liver enzymes, ammonia, lactic acid, blood cultures, and pertussis testing identified no diagnoses. Four laboratory tests showed a false positive rate (FPR) exceeding 50%: blood gas (57.6%), inborn errors of metabolism testing (51.7%), electrolytes (51.3%), and bilirubin (52.8%). Consultations were provided to 440 patients (42.2%), identifying explanatory diagnoses in 122 (27.7%) and incidental findings in 70 (15.9%).

Conclusions: Diagnostic testing and consultations are prevalent but rarely yield significant results, often with high FPR. Consequently, the routine application of these diagnostic approaches should be reconsidered in the absence of targeted clinical indications.