The epidemiology of medication prescribing errors in the emergency department.

Medication errors are a major concern in the Emergency Department (ED). We examined the epidemiology of medication prescribing errors among consecutive adult ED patients during two 10-day periods in the adult ED prior to implementing computerized provider order entry. 479 patients had no medication orders and 1,301 had 3,393 orders. Per 100 orders there were 3.7 potential adverse drug events, 337.1 medication prescribing errors, and 24.2 rule violations.