Identifying and quantifying medication errors: evaluation of rapidly discontinued medication orders submitted to a computerized physician order entry system.

All methods of identifying medication prescribing errors are fraught with inaccuracies and systematic bias. A systematic, efficient, and inexpensive way of measuring and quantifying prescribing errors would be a useful step for reducing them. We ask if rapid discontinuations of prescription-orders--where physicians stop their orders within 2 hours--would be an expedient proxy for prescribing errors? To study this we analyzed CPOE-system medication orders entered and then discontinued within 2 hours. We investigated these phenomena in real time via interviews with corresponding ordering physicians. Each order was also independently reviewed by a clinical pharmacist or physicians. We found that of 114 rapidly discontinued orders by 75 physicians, two-thirds (35 of 53, PPV = 66; 95% CI = 53-77) of medication orders discontinued within 45 minutes were deemed inappropriate (overdose, underdose, etc.). Overall, 55% (63 of 114; 95% CI = 46-64%) of medication orders discontinued within 2 hours were deemed inappropriate. This measure offers a rapid, constant, inexpensive, and objective method to identify medication orders with a high probability of error. It may also serve as a screening and teaching mechanism for physicians-in-training.