The accuracy of the Learning Disability Screening Questionnaire (LDSQ) in classifying severity of impairment: A brief report

Background: Outcomes for people with an intellectual disability (ID) may differ depending on the severity of the condition. This study evaluated whether a tool used to screen for the presence of ID could also give an early indication of severity, in order to help inform future support needs. Methods: Multicategory receiver operating characteristic (ROC) analysis was used to examine how well the Learning Disability Screening Questionnaire (LDSQ) could classify individuals (n = 238) in terms of severity of intellectual impairment. Results: Mean LDSQ scores increased across diagnostic categories from “severe impairment” to “no ID” as expected. However, overall classification accuracy was inadequate to justify extending the use of the scale to placing individuals in severity categories (VUS = .58 and Youden Index = .49). Conclusions: Although the LDSQ can accurately discriminate between those with and without ID, results indicated that it may not accurately classify individuals in terms of severity of intellectual impairment.