Relationship between medication errors and adverse drug events.
This study examines medication errors and adverse drug events in three medical units. Medication errors were identified by self-report, nurse chart review, and medication sheet review. Adverse drug events (ADEs) or potential ADEs were identified by spontaneous reporting and daily chart review. The rate of medication error was 5.3 per 100 orders or 1.4 per patient admission, higher than in previous studies. Adverse drug events related to medication errors were rare (5 per 530 order errors, or 0.9%), and all were preventable. The authors conclude that inpatient medication errors are more common than previously reported and do not often lead to ADEs; however, many of the ADEs related to medication errors could be prevented by computer order entry.