Pharmacist dispensing error: The effect of neighbourhood density and time pressure on accurate visual perception of drug names

Objective: Two potential causes of dispensing error; neighbourhood density and time pressure, were analysed using a lab-based dispensing task. Method: 60 participants were asked to select a target drug name from a selection of mock drug packets shown on a computer screen, where one or four similar non-targets might be present. Half of the group (30) completed the task under a 12 minute time limit. Results: The number of similar drug names present had a significant impact on performance; four non-targets increased reaction times and decreased accuracy in comparison to trials where only one non-target was present. An additional deficit in accuracy associated with the imposed time limit was found. Conclusion: The reported findings indicate that the number of similarly named products in proximity to a target medication can have an adverse effect upon selection accuracy. This adverse effect is increased when a time constraint is applied.