The cognitive complexity of a provider order entry interface.

Computer-based provider order entry (POE) can reduce the frequency of preventable medical errors. However, overly complex interfaces frequently pose a challenge to users and impede clinical efficacy. We present a cognitive analysis of clinician interaction with a commercial POE system. Our investigation was informed by the distributed resources model, a novel approach designed to describe the dimensions of user interfaces that introduce unnecessary cognitive complexity. This approach characterizes the relative distribution of user's internal representations and external representations embodied in the system or environmental artifacts. The research consisted of two component analyses: a modified cognitive walkthrough evaluation and a simulated clinical ordering task performed by seven physicians. The analysis revealed that the configuration of resources placed unnecessarily heavy cognitive demands on the user, especially those who lacked a robust conceptual model of the system. The resources model was also used to account for patterns of errors produced by clinicians.