Interruptions during the medication administration process have been linked to an increased risk of error. This simulation study investigated the effect of interruptions on medication prescribing errors, using a controlled experimental design during which physicians were interrupted while prescribing within a computerized provider order entry system. Interruptions did not result in an increase in prescribing errors, but did significantly increase the time needed to complete complex prescribing tasks. The investigators hypothesize that CPOE systems provide visual cues that may help providers resume interrupted tasks without increasing the potential for error.