Psychometric properties of self-administered Lequesne Algofunctional Indexes in patients with hip and knee osteoarthritis: an evaluation using classical test theory and Rasch analysis
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Franco Franchignoni & Fausto Salaffi & Andrea Giordano & Alessandro Ciapetti & Marina Carotti &Marcella Ottonello
- چاپ و سال / کشور: 2011
Description
The aim of this study is to perform a psychometric analysis of the Lequesne Algofunctional Indexes (LAI) for the severity of osteoarthritis (OA) of the hip (LAI-hip) and knee (LAI-knee), using classical test theory (CTT) and Rasch analysis. Questionnaires were completed by 1,214 patients with symptomatic OA of the knee (n=697) and hip (n=517). Internal consistency was evaluated using Cronbach’s alpha and an item-to-total correlation. Dimensionality was investigated with a factor analysis. Raw scores underwent Rasch analysis. Cronbach’s alpha was 0.84 for LAI-hip and 0.82 for LAI-knee. LAI-hip resulted in unidimensionality according to the factor analysis, while LAI-knee supported both a single and a two-factor solution (items 1– 6b and 7–10, respectively). At Rasch analysis, the rating categories of item ‘maximum distance walked’ did not comply with the criteria for category functioning in either LAI-hip or LAI-knee. A test of the residual correlation showed item dependency in both LAI-hip and LAI-knee. Misfitting items were present in both the scales. According to both CTT and Rasch analysis, in our two samples representing a wide spectrum of both hip and knee OA severity the LAI-hip and LAI-knee showed a series of drawbacks, which rendered both questionnaires inadequate in relation to their metric properties and severely limit their ability to perform, as a composite measure, in line with the main aims of their developers
Clin Rheumatol Received: 22 March 2011 / Revised: 19 May 2011 / Accepted: 27 May 2011
