Disability is an important multifaceted construct. Identifying sources of disability could help optimise patient care. The aim of this study was to test an approach that not only estimates severity of disability, but also identifies the source(s) of this disability. An online survey was used to collect data from a convenience sample, recruited via email and social media invitations. Two generic measures of disability, the 8-item Universal Disability Index (UDI8) and Groningen Activity Restriction Scale (GARS) were used to estimate the prevalence and severity of disability in this sample. Non-zero UDI8 item responses generated conditional sub-questions, in which participants could attribute their activity limitations to one or more sources (pain, fatigue, worry, mood, and other). This allowed for a decomposition of UDI8 scores into source components.Background
Methods
Disability is an important multifaceted construct. The aim of this study was to develop and evaluate a brief, generic self-reported disability questionnaire: the Universal Disability Index (UDI). Convenience sampling was used to collect general population data via an online survey. Data were randomly divided into training and validation subsets. The dimensionality and structure of eight UDI questionnaire items were evaluated using exploratory factor analysis (EFA, training subset) followed by confirmatory factor analysis (CFA, validation subset). To assess concurrent validity, the UDI summed score from the full dataset was compared to the Groningen Activity Restriction Scale (GARS) and the Graded Chronic Pain Scale (GCPS) disability scores. Internal consistency was also assessed.Background
Methods
