Psychometric properties of QuickDASH - a classical test theory and Rasch analysis study

Area of Science:

• Orthopedics
• Rehabilitation Medicine
• Psychometrics

Background:

• The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire is widely used.
• The QuickDASH is a shortened version intended for efficient patient assessment.
• Robust psychometric properties are essential for accurate clinical outcome measurement.

Purpose of the Study:

• To conduct a comprehensive psychometric analysis of the QuickDASH using classical test theory and Rasch analysis.
• To evaluate the metric properties, including unidimensionality and reliability, of the QuickDASH.
• To identify potential areas for revision of the QuickDASH questionnaire.

Main Methods:

• Psychometric analysis of 283 patients with upper limb disorders.
• Utilized classical test theory and Rasch analysis on QuickDASH item responses.
• Exploratory factor analysis and rating scale diagnostics were performed.

Main Results:

• Disordered response categories were identified and collapsed.
• Unidimensionality was generally supported, but item 10 ('tingling') showed misfit and was removed.
• The resulting 10-item QuickDASH demonstrated good, but not excellent, reliability.

Conclusions:

• The unidimensionality of the QuickDASH was not fully confirmed.
• Item 10 ('tingling') does not align with the primary construct measured.
• Further investigation into response categories and potential revision is recommended for improved clinical utility.