Statistical analysis
The primary outcome was the proportion of nonisolated ESBL-E days among all identified ESBL-E days. Secondary outcomes were time intervals (1) between the day of admission and the day the first screening sample was collected or (2) the day the first ESBL-E–positive screening or clinical culture was obtained until the first day of contact isolation. For categorical parameters, we calculated number and percentages; for continuous parameters, we calculated median and interquartile ranges (IQRs). Wald confidence intervals were computed at the 95% level. Differences were tested by χ