LAUSR

To the Editor: Sickle cell disease (SCD) affects ~100,000 people in the United States, of which 36,000 are children.1 SCD is characterized by vaso-occlusive pain crises, with those pain crises leading to high emergency department (ED) utilization.2 Evaluation of ED visits by all children across the United States reveals that >70% occur in the community rather than academic EDs.3,4 This raises concern for the generalizability of research done using pediatric populations within academic EDs. However, children with SCD require specialized care typically provided in academic institutions and the distribution of ED visits in patients with SCD is unknown. We combined data from the 2015, 2016, and 2017 Nationwide Emergency Department Sample (NEDS) to analyze the utilization of teaching versus nonteaching EDs for pediatric sickle cell visits. NEDS is a stratified sample of ED visits from 35 (2015) to 37 (2016 and 2017) states, weighted to represent national numbers. Hospital types within the NEDS framework are categorized as metropolitan teaching, metropolitan nonteaching, or rural/nonmetropolitan.5 Consistent with NEDS guidance, metropolitan nonteaching and rural hospitals were categorized as nonteaching for all analyses. Visits were identified as being by a patient with SCD using International Classification of Diseases (ICD)-9 diagnosis codes of 282.41, 282.42, and 282.6* or an ICD-10 code of D57.* (except D57.3: sickle cell trait). Patients 18 years or younger were considered children and patients older than 18 years were considered adults. Visits were classified as occurring at a children’s hospital ED if >75% of visits to that ED were made by children, and all children’s hospital EDs were categorized as teaching hospitals.6 Percentages were compared using χ2 analyses. The total unweighted sample size in the NEDS between 2015 and 2017 was 96,729,568 visits. Of those visits, 236,373 were visits by patients with SCD (195,914 by adults and 40,459 by children). Those visits were weighted to represent 433,121,848 ED visits nationally; 1,055,793 (0.24%) of which were by patients with SCD (Fig. 1). Of the visits by patients with SCD, 870,958 (82.5%) were by adults and 184,835 (17.5%) were by children. Analysis by hospital type across all ages revealed that a higher percentage of ED visits by patients with SCD occurred in teaching hospitals (76.4%; 95% confidence interval [CI], 73.0-79.8) compared with visits by patients without SCD (56.3%; 95% CI, 54.5-58.2) (P< 0.01). Visits by children with SCD were more likely to occur in a teaching hospital (87.1%; 95% CI, 84.1-90.2) compared with adults with SCD (74.1%; 95% CI, 70.4-77.9) and children without SCD (59.6%; 95% CI, 57.0-62.2; both comparisons P< 0.01). Restricting the analysis to visits at children’s hospitals revealed that children with SCD had a higher proportion of ED visits at children’s hospitals (27.2%; 95% CI, 12.8-41.5) than children without SCD (10.5%; 95 CI, 5.915.1) (P< 0.01). We found a significantly higher use of teaching hospitals for both adults and children with SCD compared with the rest of the population. For children with SCD, almost 9 of 10 ED visits occur in teaching hospitals and over one-fourth occur in children’s hospital EDs. Although not every state is included in the NEDS and the