Evaluation of the Pain Impact Index for Community-Dwelling Older Adults Through the Application of Rasch Modelling.
Julia F-M Gilmartin-Thomas, Andrew Forbes, Danny Liew, John J McNeil, Flavia M Cicuttini, Alice J Owen, Michael E Ernst, Mark R Nelson, Jessica Lockery, Stephanie A Ward, Ljoudmila Busija, undefined ASPREE Investigator Group
Pain Pract | Published : 2021
OBJECTIVE: Evaluate the Pain Impact Index, a simple, brief, easy-to-use, and novel tool to assess the impact of chronic pain in community-dwelling older adults. METHODS: A Rasch modelling analysis was undertaken in Stata using a partial credit model suited to the Likert-type items that comprised the Index. The Index was evaluated for ordering of category thresholds, unidimensionality, overall fit to the Rasch model, measurement bias (Differential Item Functioning, DIF), targeting, and construct validity. RESULTS: The four-item Pain Impact Index was self-completed by 6454 community-dwelling Australians who were aged at least 70 years and experienced pain on most days. Two items showed evidenc..View full abstract