“…This would ensure adequate variation in ondansetron use and enable the establishment of a lag period, which facilitates the detection of a change in outcomes in timeseries designs. 10 Hospitalization was defined as admission to an observation (ie, short stay, 24 hours) or inpatient unit. For revisit outcomes, a 3-day window, generally accepted as an ED quality of care metric, 21 23 were used to assess the associations, at the hospital level, of ondansetron use category with the primary and secondary outcomes adjusting for potential confounding by observed baseline characteristics identified in bivariate analysis (ie, age, sex, race, season, admission time, prior visit for AGE, laboratory testing, diagnostic imaging, and rotavirus diagnosis), including quadratic terms when significant.…”