Investigation of correlation between house-staff work hours and prescribing errors

Purpose. The possible correlation between the frequency and significance of prescribing errors and the number of hours worked during a 24-hour shift by hospital house staff was studied. Methods. A prospective observational trial was conducted in two internal medicine units at an academic medical center. Orders written by medical house staff covering the study units between January 8 and March 10, 2001, were collected daily and evaluated for obvious prescribing errors, the type and significance of the errors, and the number of hours the resident had worked during a 24-hour shift at the time of the prescribing error. Results. A total of 45,366 orders (including orders for medications, laboratory tests, diagnostic procedures, and nursing care) were entered on the study units during the study period. A total of 498 erroneous prescribing orders were identified. A majority of the erroneous orders (77%) could have resulted in significant morbidity or mortality had they reached the patient. The most common errors involved the wrong dose (18%), the wrong dosage frequency (15%), and duplicate orders (15%). There was no statistically significant correlation between the number of hours worked and the frequency or significance of the errors. Conclusion. The number of hours worked by medical house staff during a 24-hour shift did not appear to affect the frequency or significance of their prescribing errors.