Background Computerised provider order entry (CPOE) is an important patient safety intervention that has encountered significant barriers to implementation. The usability of a CPOE system plays a significant role in its acceptance. The authors conducted a heuristic evaluation of a CPOE order set system to uncover existing usability issues prior to implementation.

Methods A heuristic evaluation methodology was used to evaluate the usability of a CPOE test order set system. There are 10 heuristic principles, such as error prevention, to help users identify and recover from errors. Evaluators included a staff physician with extensive clinical experience, and three engineers with expertise in heuristic evaluation methodology. The results of the heuristic evaluation were used to create a user centred design prototype.

Results 92 unique heuristic violations were found for the CPOE test order set system, including 35 identified by the clinician and at least one engineer, and 57 of the 92 violations (62%) found only by the clinician. All evaluators identified at least one violation of each of the 10 usability heuristics in their analysis of the CPOE system. A user centred design prototype was created to demonstrate changes that could improve usability.

Interpretation The CPOE test order set system had many usability heuristic violations. Many violations were found by a clinician with knowledge of the heuristic evaluation process. Implementation of the CPOE system was deferred and a new user centred design prototype was developed for future study. The authors recommend conducting heuristic evaluations early in the process of designing, selecting and implementing CPOE systems.