Medication safety in the ambulatory chemotherapy setting.

Background: Little is known concerning the safety of the outpatient chemotherapy process. In the current study, the authors sought to identify medication error and potential adverse drug event (ADE) rates in the outpatient chemotherapy setting.
Methods: A prospective cohort study of two adult and one pediatric outpatient chemotherapy infusion units at one cancer institute was performed, involving the review of orders for patients receiving medication and/or chemotherapy and chart reviews. The adult infusion units used a computerized order entry writing system, whereas the pediatric infusion unit used handwritten orders. Data were collected between March and December 2000.
Results: The authors reviewed 10,112 medication orders (8008 adult unit orders and 2104 pediatric unit orders) from 1606 patients (1380 adults and 226 pediatric patients). The medication error rate was 3% (306 of 10,112 orders). Of these errors, 82% occurring in adults (203 of 249 orders) had the potential for harm and were potential ADEs, compared with 60% of orders occurring in pediatric patients (34 of 57 orders). Among these, approximately one-third were potentially serious. Pharmacists and nurses intercepted 45% of potential ADEs before they reached the patient. Several changes were implemented in the adult and pediatric settings as a result of these findings.
Conclusions: In the current study, the authors found an ambulatory medication error rate of 3%, including 2% of orders with the potential to cause harm. Although these rates are relatively low, there is clearly the potential for serious patient harm. The current study identified strategies for prevention.