Accuracy and time requirements of a bar-code inventory system for controlled substances

The effect of a bar-code system on personnel time requirements and data-entry accuracy in an existing automated controlled substances inventory system was determined. In the previous system, technicians used a keyboard and alphanumeric codes to enter into the computer data about the physical transfer of controlled substances among hospital areas. A system for barcode data entry was adapted for use with the existing procedure. After learning to use the bar-code system, four experienced technicians entered data by the keyboard method for eight days and the bar-code method for eight days during a 32-day study period. The amount of time required to enter all transactions and the accuracy of data entry were measured. Mean data-entry times for the keyboard and bar-code methods were not significantly different, most likely because of the greater number of manipulations needed for bar-code data entry. The mean percentage error associated with the bar-code method (0.79%) was significantly less than the error associated with the keyboard method (1.53%). For this particular computer system in which bar-code data entry was adapted to existing procedures, use of bar codes to enter controlled substances inventory data was not substantially faster but was more accurate than a traditional key-board data-entry method.