Emergency Department Volume and Delayed Diagnosis of Serious Pediatric Conditions.

IMPORTANCE: Diagnostic delays are common in the emergency department (ED) and may predispose to worse outcomes.

OBJECTIVE: To evaluate the association of annual pediatric volume in the ED with delayed diagnosis.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included all children younger than 18 years treated at 954 EDs in 8 states with a first-time diagnosis of any of 23 acute, serious conditions: bacterial meningitis, compartment syndrome, complicated pneumonia, craniospinal abscess, deep neck infection, ectopic pregnancy, encephalitis, intussusception, Kawasaki disease, mastoiditis, myocarditis, necrotizing fasciitis, nontraumatic intracranial hemorrhage, orbital cellulitis, osteomyelitis, ovarian torsion, pulmonary embolism, pyloric stenosis, septic arthritis, sinus venous thrombosis, slipped capital femoral epiphysis, stroke, or testicular torsion. Patients were identified using the Healthcare Cost and Utilization Project State ED and Inpatient Databases. Data were collected from January 2015 to December 2019, and data were analyzed from July to December 2023.

EXPOSURE: Annual volume of children at the first ED visited.

MAIN OUTCOMES AND MEASURES: Possible delayed diagnosis, defined as a patient with an ED discharge within 7 days prior to diagnosis. A secondary outcome was condition-specific complications. Rates of possible delayed diagnosis and complications were determined. The association of volume with delayed diagnosis across conditions was evaluated using conditional logistic regression matching on condition, age, and medical complexity. Condition-specific volume-delay associations were tested using hierarchical logistic models with log volume as the exposure, adjusting for age, sex, payer, medical complexity, and hospital urbanicity. The association of delayed diagnosis with complications by condition was then examined using logistic regressions.

RESULTS: Of 58 998 included children, 37 211 (63.1%) were male, and the mean (SD) age was 7.1 (5.8) years. A total of 6709 (11.4%) had a complex chronic condition. Delayed diagnosis occurred in 9296 (15.8%; 95% CI, 15.5-16.1). Each 2-fold increase in annual pediatric volume was associated with a 26.7% (95% CI, 22.5-30.7) decrease in possible delayed diagnosis. For 21 of 23 conditions (all except ectopic pregnancy and sinus venous thrombosis), there were decreased rates of possible delayed diagnosis with increasing ED volume. Condition-specific complications were 11.2% (95% CI, 3.1-20.0) more likely among patients with a possible delayed diagnosis compared with those without.

CONCLUSIONS AND RELEVANCE: EDs with fewer pediatric encounters had more possible delayed diagnoses across 23 serious conditions. Tools to support timely diagnosis in low-volume EDs are needed.