Reliability, validity, and applicability of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0) for adults with multiple sclerosis

Purpose: To investigate the measurement properties of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0) with respect to test-retest stability, alternate form reliability, construct validity and applicability. Method: Data on satisfaction and quality of life impacts of mobility devices were obtained from 81 community-based adults with Multiple Sclerosis, using the QUEST 2.0 and the Psychosocial Impact of Assistive Devices Scale (PIADS). Subjects were assigned to four groups and a second QUEST 2.0 was administered one week later. Groups differed with respect to the format and the order in which alternate forms were presented. Measures of association were calculated between QUEST 2.0 and PIADS (n=81) and between QUEST 2.0 alternate forms (n=48). Respondents' reactions were considered. Results: The device subscale, services subscale, and total QUEST 2.0 scores achieved good test-retest stability (ICC 0.82, 0.82, 0.91). Alternate-form equivalence (ICC 0.89, 0.76, 0.91) was lower for services. The positive correlations between QUEST 2.0 and the three PIADS dimensions were fair to moderate for device and total QUEST 2.0 (r(p) 0.34 to 0.45) and fair with services (r(p) 0.27 to 0.30). The tool was positively received, with some restrictions for the services subscale. Conclusions: These findings on the psychometric properties of the QUEST 2.0 reinforce the relevance of the device subscale as an important outcome measure for assistive technology MS users. Further assessment of the services subscale is needed.