Ordering errors by first-year residents: evidence of learning from mistakes.

Objective and Design: To study patterns of ordering errors, we reviewed charts of patients cared for by first-year residents at our community-based teaching hospital.
Results: In month one, 39 of 1248 orders (3.1%) were rated as errors. In contrast, 9 of 1072 orders (0.84%) in month six were rated as errors (p < 0.001). Of the 48 errors identified, 36 (75%) related to medications (choice, dose, route, frequency, or duration). Over half (53%) of these errors involved antimicrobials, pulmonary medications, or diabetes-related drugs. For all errors, half (24/48) were identified by attending physicians, with hospital support staff noting most of the remaining errors (43.8%). Errors were ultimately corrected by the first-year resident in over half of the cases (52%); attending physicians corrected 16 of 39 errors (41%) in month one but only one of nine errors (11%) in month six. Errors by first-year residents were primarily attributed to inattention (45.8%) or deficits in clinical knowledge (43.8%). No adverse effects resulted from any of the ordering errors identified. Primary consequences of errors included inconvenience to staff (50%), delay in treatment or diagnosis (31.3%), or receiving unneeded medication (18.8%).
Conclusions: The number of medical errors decreases with experience. Our results highlight the importance of clinical supervision during the initial months of training.