Kulvatunyou N, et al. - Researchers sought for factors associated with acute appendicitis (AA) perforation, including the effect of system time (ST) delay, after controlling for patient time (PT) delay. Reviewing medical records of patients at a tertiary referral hospital from October 2009 through September 2013, they identified 747 patients who underwent surgery for AA. Outcomes revealed no adverse effect of the ST delay of >12 h on the incidence of advanced AA, once PT delay was limited to ≤24 h. Risk of advanced AA was observed in correlation with age >50 y, WBC >15,000, PT delay >12 h, and the presence of fecaliths.