Development, Internal Construct, and Unidimensionality of the Tetraplegia Upper Limb Activities Questionnaire, TUAQ. Part 1

Abstract

ObjectiveThis study aims to develop a patient-reported outcome measure that focuses on relevant daily activities relying on upper extremity for individuals with tetraplegia. DesignCross-sectional study. SettingSpinal cord injury units in 2 countries. ParticipantsNinety-nine individuals (N=99) with C2-C8, American Spinal Injury Association Impairment Scale A-D tetraplegia, mean age 46 years, 1- 43 years post injury. InterventionsThirteen items included in the initial testing were chosen from 708 activity limitations identified by individuals with tetraplegia. Items were pilot tested for wording, response options, and relevance for both performance and satisfaction. Items were analyzed and reselected using exploratory factor analysis and Rasch analysis for local dependency, dimensionality, differential item functioning (DIF), threshold response, and targeting. Main Outcome MeasuresNot applicable. ResultsExploratory factor analysis supported a 2-factor solution for both performance and satisfaction. While data fit the Rasch model, there was evidence of local dependency and multiple disordered thresholds. Three items were removed because of high interitem correlation and DIF and the scale rescored to 5 response options. The remaining 10 items demonstrated fit to the Rasch model, with no local dependency, no multidimensionality, no item or person misfit, and minimal disordered thresholds. ConclusionsResults support the internal construct validity and unidimensionality of the Tetraplegia Upper Limb Activities Questionnaire (TUAQ), a 10-item, 5-response patient-reported outcome measure assessing performance and satisfaction with activities targeted to the upper extremity for individuals with tetraplegia. Further testing is required and ongoing to evaluate reliability and responsiveness of the TUAQ.