Assessing the efficacy, effectiveness, and cost-effectiveness of assistive technology interventions for enhancing mobility.

PURPOSE The aim of this paper is to highlight the contributions that complementary efficacy, effectiveness, and cost-effectiveness studies can make to assessing the outcomes of assistive technology interventions for enhancing mobility. METHOD The terms, 'assistive technology outcomes research' and 'assistive technology interventions', are defined. Several bases are examined for the shortage of outcomes research pertaining to mobility-related assistive technology interventions. Three presuppositions are described for the research strategy of interlocking studies being recommended. They are assigning priority to evaluating both recently developed assistive technologies and ones that have long been available, acknowledging the complexity of assistive technology as an intervention, and appreciating the trade-offs necessary for strengthening studies' internal and external validity. Some key study preparations are considered, including treatment theory, treatment specification, and the selection of outcome domains and measures. The essential features of efficacy, effectiveness, and cost-effectiveness studies are outlined, and their interdependence is stressed. RESULTS AND CONCLUSIONS To assess the outcomes of assistive technology interventions for mobility in ways that are both methodologically sound and relevant to stakeholder needs, a research strategy is required involving mutually reinforcing efficacy, effectiveness, and cost-effectiveness studies. Collaborative arrangements and funding methods are discussed for fostering the needed research.