Analysis

The system outputs data files consisting of encoded time-stamps of system events and user actions. A program was written which parses these files to link user responses to the system stimuli, creating decision events (DE) for which a variety of attributes are captured, including

the correctness of a decision (correct, incomplete because no user action occurred, or incorrect because only incorrect user actions occurred),
the correct time of a decision (the interval between the system stimulus and a correct user response),
the first guess time of a decision (the interval between a system stimulus and any user response),
and various parameters of a decision's "prior cousin" (i.e., the correctness and "correct times" of an ECG decision prior to an index BP decision, for example).

These parsed DE data were imported into a database, a spreadsheet program, and SPSS for further analysis. For this small pilot study, only the correctness and "correct times" are evaluated, since they represent the chief end points of the study-the accuracy and speed of clinician interpretation, respectively.

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