This AHRQ–funded study applied new screening criteria to capture health care injuries that occurred before hospitalization, in addition to those during a hospitalization. Investigators used the Wisconsin Medical Injury Prevention Program (WMIPP) screening method to analyze more than 318,000 pediatric discharges from 134 hospitals. The overall rate of medical injuries was 3.4%, with the most frequent areas for improvement around medications, procedures, and devices. The authors suggest that use of the WMIPP screening process may serve as an important method to survey patient safety in large population-based samples.