Year, Volume, Issue, Page(s):15, 38, 3, 315-325
Article describes the development and psychometric characteristics of the Spinal Cord Injury – Quality of Life (SCI-QOL) Anxiety item bank. Grounded-theory based qualitative item development methods were used to develop a calibrated item bank and computer adaptive test (CAT) to assess anxiety symptoms in individuals with spinal cord injury (SCI). Analyses included confirmatory factor analysis, item response theory calibration, and evaluation of differential item functioning. Scores were transformed to the Patient Reported Outcomes Measurement Information System (PROMIS) metric and statistical linking techniques were used to develop a crosswalk with the Generalized Anxiety Disorder (GAD-7), a widely used anxiety measure. Thirty-eight items assessing anxiety, 17 of which were PROMIS items, were administered to 716 individuals with traumatic SCI recruited from 5 SCI Model Systems centers and one Veterans Affairs medical center. After 13 items (including 2 PROMIS items) were removed, factor analyses confirmed unidimensionality. Item response theory analyses were used to estimate slopes and thresholds for the final 25 items (15 from PROMIS). The observed Pearson correlation between the SCI-QOL Anxiety and GAD-7 scores was 0.67. The SCI-QOL Anxiety item bank demonstrates excellent psychometric properties and is available as a CAT or short form for research and clinical applications.