title: Geographic Variation in the Use of Low-Acuity Pediatric Emergency Medical Services.
abstract: OBJECTIVE
  The aim of this study was to examine geographic variation in pediatric low-acuity emergency medical services (EMS) use in Washington, DC.
  
  
  METHODS
  This cross-sectional analysis of low-acuity EMS transports evaluated arrivals at 2 emergency departments and included 93% of pediatric transports in Washington, DC, during the study period. Low-acuity classification was defined as a triage emergency severity index of 4 or 5 not resulting in transfer, admission, or death. Logistic regression compared low-acuity visits arriving via EMS with all other low-acuity visits. Home zip code represented geographic location. Covariates included patient age, sex, race/ethnicity, hour of emergency department arrival, and insurance status.
  
  
  RESULTS
  There were 45,454 low-acuity visits among children aged 0 to 17 years. Of these, 3304 (7.3%) arrived via EMS. The mean age was 5.6 (±5.0) years. Most were African American (84.3%) and had Medicaid insurance (87.3%). Geographic variation predicted EMS use. Adjusted odds ratios (ORs) of using EMS varied from 1.11 to 2.54 when compared with the lowest EMS use zip code. Odds of EMS use were higher among those with public insurance (adjusted OR [adj OR], 1.71; 95% confidence interval [CI], 1.46-2.00) and those with evening and overnight arrivals (evening arrival, adj OR of 1.65 and 95% CI of 1.47-1.86; overnight arrival, adj OR of 2.98 and 95% CI of 2.43-3.65).
  
  
  CONCLUSIONS
  After adjusting for known covariates, residential zip code was associated with low-acuity EMS activation, stressing the importance of geographic variation in EMS use. Providing alternate means of transportation, or targeted education to certain residential areas, may decrease unnecessary EMS activation.
authors.affiliation: From the *Department of Pediatrics; and †Department of Pediatrics and Emergency Medicine, Children's National Medical Center, George Washington University School of Medicine and Health Sciences; and ‡Department of Geography, George Washington University, Washington, DC.
authors.forename: Emily F
authors.initials: EF
authors.lastname: Gregory
authors.forename: James M
authors.initials: JM
authors.lastname: Chamberlain
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Teach
authors.forename: Ryan
authors.initials: R
authors.lastname: Engstrom
authors.forename: David J
authors.initials: DJ
authors.lastname: Mathison
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004219:District of Columbia; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005843:Geography; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D010372:Pediatrics; D014218:Triage / Q000706:statistics & numerical data*