Fig. 3
Preoperative time in injured patients requiring emergency surgery: first versus second to fourth academic quartilea. Box plots of time from ED arrival to operating room in injured patients who underwent emergency surgery. a All injured patients, b patients who presented during business hours, and c patients who presented during off-hoursb. The solid line within the box represents the median, the box represents the 25th and 75th percentiles, and the whiskers represent the lower and upper extremes. The p value was derived from the Mann–Whitney U-test. aIn Japan, the academic cycle typically begins on 1 April each year. The first academic quartile therefore corresponds to April to June, and the second to fourth quartile corresponds to July to March. bOff-hours are defined as the period from 6:01 pm to 8:00 am on weekdays plus the entire weekend. ED emergency department