The relationship of usability to medical error: an evaluation of errors associated with usability problems in the use of a handheld application for prescribing medications.

This paper describes an innovative approach to the evaluation of a handheld prescription writing application. Participants (10 physicians) were asked to perform a series of tasks involving entering prescriptions into the application from a medication list. The study procedure involved the collection of data consisting of transcripts of the subjects who were asked to "think aloud" while interacting with the prescription writing program to enter medications. All user interactions with the device were video and audio recorded. Analysis of the protocols was conducted in two phases: (1) usability problems were identified from coding of the transcripts and video data (2) actual errors in entering prescription data were also identified. The results indicated that there were a variety of usability problems, with most related to issues of ease of use. In addition, other problems were identified which were related to limitations of the content of the program. In examining the relationship between usability problems and errors, it was found that certain types of usability problems were closely associated with the occurrence of specific types of errors in prescription of medications. Implications for the improvement of safety of health care information systems are discussed.