Impact of increasing ondansetron use on clinical outcomes in children with gastroenteritis.

IMPORTANCE: Ondansetron hydrochloride use in children with gastroenteritis is increasing rapidly; however, little is known about its impact on outcomes.

OBJECTIVE: To determine whether increasing emergency department ondansetron use has resulted in a reduction in intravenous rehydration rates.

DESIGN, SETTING, AND PARTICIPANTS: Retrospective observational analysis of eligible visits included in the Pediatric Health Information System administrative database. Eligible institutions included 18 emergency departments geographically distributed across the United States, and participants included 804,000 patients aged 0 to 18 years who were diagnosed as having gastroenteritis in an emergency department at an eligible participating institution between January 1, 2002, and December 31, 2011.

INTERVENTIONS: The presence or absence of oral ondansetron administration was identified for each patient through database review. Visits were categorized based on institutional ondansetron use: low (<5% administered ondansetron), medium (5%-25%), or high (>25%).

MAIN OUTCOMES AND MEASURES: We conducted hospital-level analyses of the associations between ondansetron use and 3 outcomes: intravenous rehydration (primary), hospitalization, and emergency department revisits within 3 days. Time-series regression models were used, adjusting for demographic characteristics, laboratory testing, diagnostic imaging, and rotavirus infection.

RESULTS: A total of 804,000 eligible patient visits were identified. Oral ondansetron use increased from a median institutional rate of 0.11% (interquartile range, 0.04%-0.44%) of patient visits in 2002 to 42.2% (interquartile range, 37.5%-49.1%) in 2011 (P < .001). Intravenous rehydration was administered to 43,413 of 232,706 children (18.7%) during the low ondansetron period compared with 59,450 of 334,264 (17.8%) during the high ondansetron period (adjusted percentage change = -0.33%; 95% CI, -1.86% to 1.20%). During the transition from low to high ondansetron use, we observed no change in the hospitalization rate (adjusted percentage change = -0.33%; 95% CI, -0.95% to 0.29%), but emergency department revisits decreased (adjusted percentage change = -0.31%; 95% CI, -0.49% to -0.13%). The change in all 3 outcomes varied widely between low and high ondansetron use categories at an institutional level. Oral ondansetron was provided to 13.5% (95% CI, 13.3% to 13.7%) of children administered intravenous rehydration.

CONCLUSIONS AND RELEVANCE: Although ondansetron use increased during the study period, intravenous rehydration rates were unchanged. Most children administered intravenous fluids did not receive oral ondansetron. Our findings highlight the need to focus efforts to administer ondansetron to children at greatest risk for oral rehydration failure.