IMPACT: an object-oriented graphical environment for construction of multimedia patient interviewing software.

This paper describes our software for rapid construction of multimedia computer interviews. The program, which we call IMPACT, was designed to measure preferences for health outcomes using the standard gamble and other decision analytic techniques. IMPACT is also a multimedia shell program that allows researchers to interactively construct patient interviewing instruments without programming or scripting. It supports the integration of text, graphics, synthesized speech, digital sound and QuickTime movies into interviewing instruments through a point-and-click interface. IMPACT also supports branching logic and randomizing the presentation order of materials within an instrument. This allows customization of the presentation based on patient responses and facilitates experimental designs. Validation studies show that preference assessments performed using IMPACT have high test-retest reliability (r = 0.83, n = 96). Post-test surveys (n = 52) show that most subjects understand valuation methods (86%) and believe that the explanations provided were clear (96%) and that methods were reasonable (80%). The majority of subjects thought the preference assessment methods were not difficult to use (53%) and would have been comfortable using such methods for medical decisions (53%).