title: Time-series analysis of ondansetron use in pediatric gastroenteritis.
abstract: OBJECTIVE
  Emergency department use of ondansetron in children with gastroenteritis is increasing; however, its effect on clinical outcomes is unknown. We aimed to determine whether increasing ondansetron usage is associated with improved outcomes in children with gastroenteritis.
  
  
  METHODS
  A retrospective cohort study was conducted at The Hospital for Sick Children, Toronto, Canada. Eligible children included those younger than 18 years old with gastroenteritis who presented to an emergency department between 2003 and 2008. There were 22,125 potentially eligible visits; 20% were selected at random for chart review. The primary outcome measure, the intravenous rehydration rate, was evaluated using an interrupted time-series analysis with segmented logistic regression. Secondary outcomes included emergency department revisits, hospitalization, and length of stay.
  
  
  RESULTS
  A total of 3508 patient visits were included in the final analysis. During the study period, there was a significant reduction in intravenous rehydration usage (27%-13%; P < 0.001) and an increase in ondansetron administration (1%-18%; P < 0.001). Time-series analysis demonstrated a level break (P = 0.03) following the introduction of ondansetron. The mean length of stay for children declined from 8.6 ± 3.4 to 5.9 ± 2.8 hours, P = 0.03. During the week following the index visit, there was a reduction in return visits (18%-13%; P = 0.008) and need for intravenous rehydration (7%-4%; P = 0.02).
  
  
  CONCLUSIONS
  Ondansetron use has increased significantly and is associated with reductions in the use of intravenous rehydration, emergency department revisits, and length of stay. The selective use of ondansetron is associated with improved clinical outcomes.
authors.affiliation: The Hospital for Sick Children, The University of Toronto, Toronto, Canada. stephen.freedman@sickkids.ca
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Freedman
authors.forename: Connie
authors.initials: C
authors.lastname: Tung
authors.forename: Dennis
authors.initials: D
authors.lastname: Cho
authors.forename: Maggie
authors.initials: M
authors.lastname: Rumantir
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Chan
mesh_terms: D000932:Antiemetics / Q000627:therapeutic use; D002170:Canada; D002648:Child; D002675:Child, Preschool; D003681:Dehydration / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D005440:Fluid Therapy; D005759:Gastroenteritis / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D009819:Office Visits; D017294:Ondansetron / Q000627:therapeutic use*; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D014839:Vomiting / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000932:Antiemetics; D017294:Ondansetron