Can the ABILHAND handle manual ability in MS?

Area of Science:

• Neurology
• Rehabilitation Medicine
• Psychometrics

Background:

• Hand dysfunction is a prevalent issue in multiple sclerosis (MS).
• Patient-reported outcome (PRO) instruments are increasingly vital for clinical trials.
• Existing manual ability measures require further examination in MS populations.

Purpose of the Study:

• To evaluate the psychometric properties of the 23-item ABILHAND scale in individuals with MS.
• To compare findings from traditional psychometric methods and Rasch measurement methods.
• To determine the suitability of ABILHAND as a PRO for MS.

Main Methods:

• Analysis of ABILHAND data from 300 people with MS.
• Application of traditional psychometric techniques (validity, reliability, data completeness).
• Utilisation of Rasch measurement methods (item fit, person validity, reliability).

Main Results:

• Both traditional and Rasch methods indicated ABILHAND is reliable and valid for MS.
• The three-category scoring function performed as expected.
• Item fit to the Rasch model was acceptable, with a wide range of item locations (-3.16 to +2.73 logits).
• High reliability was observed (Person Separation Index = 0.95).

Conclusions:

• The ABILHAND scale is a robust PRO measure for manual ability in MS.
• Rasch measurement methods provided deeper insights and suggested improvements for ABILHAND.
• These advancements can minimize type II errors in MS clinical trials.