Registered nurse review identified 296 of 600 records with triggers indicating potential AEs. Records
(n = 121) with only false positive triggers not indicating any potential AEs were not forwarded to the next review
stage. On subsequent physician review, 204 (34.0%) of patients were found to have had 563 AEs, range 1–27 AEs/
patient. A total of 442 preventable AEs were found in 161 patients (26.8%), range 1–22. Overall, triggers were found
3,598 times in 417 (69.5%) records, with a mean of 6 (median 1, range 0–176) triggers per patient. The overall
positive predictive value of the triggers was 22.9%, (range 0.0-100.0%). The final pediatric trigger tool, developed
with a second Delphi round, required 29 triggers.