Information technology solutions have proven effective at reducing some types of medication errors. For example, computerized provider order entry (CPOE) can reduce errors at the prescribing and transcription stages. Bar-coding of medications has been advocated as a means of reducing medication administration errors; although some studies have found success, others have noted unintended consequences. This study tested a "closed-loop" system that combined CPOE, bar-coding, and an electronic medication administration record (eMAR) in an academic medical center, and found that the system significantly reduced administration errors as well as potential adverse drug events. The authors note that significant changes in workflow were necessary to achieve these results and caution that successful use of this technology requires considerable attention to development and implementation.