Psychometric Properties of the Quantitative Myasthenia Gravis Score and the Myasthenia Gravis Composite Scale.

ABSTRACT:

Background

The Quantitative Myasthenia Gravis Score and the Myasthenia Gravis Composite are two commonly used outcome measures in Myasthenia Gravis. So far, their measurement properties have not been compared, so we aimed to study their psychometric properties using the Rasch model.

Methods

251 patients with stable myasthenia gravis were assessed with both scales, and 211 patients returned for a second assessment. We studied fit to the Rasch model at the first visit, and compared item fit, thresholds, differential item functioning, local dependence, person separation index, and tests for unidimensionality. We also assessed test-retest reliability and estimated the Minimal Detectable Change.

Results

Neither scale fit the Rasch model (X2p <  0.05). The Myasthenia Gravis

SUBMITTER: Barnett C 

PROVIDER: S-EPMC5240569 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature