Construct validity of instruments measuring impairments in body structures and function in rheumatic disorders: which...

Area of Science:

• Rheumatology
• Rehabilitation Medicine
• Psychometrics

Background:

• Assessing impairments in body structures and function is crucial for rheumatic disorders.
• The International Classification of Functioning, Disabilities and Health (ICF) provides a framework for classifying health conditions.
• Construct validity of measurement instruments is essential for accurate assessment.

Purpose of the Study:

• To inventory constructs used for validating instruments measuring body structure and function impairments in rheumatic diseases, based on ICF domains.
• To analyze if validation against similar constructs yields higher correlation coefficients than against dissimilar constructs.

Main Methods:

• Systematic review of papers validating instruments for body structure and function impairments in rheumatic disorders.
• Assessment of instruments' methodological properties and validation constructs.
• Comparison of pooled correlations for similar versus dissimilar constructs.

Main Results:

• 216 papers and 42 instruments were analyzed; only 16% were validated against the most similar construct.
• Construct validity estimates were generally lower when validated against dissimilar constructs, with an exception for mental function impairments.
• A correlation coefficient of 0.50 or higher was used as a criterion for good construct validity.

Conclusions:

• Validation against similar constructs tends to yield higher correlation coefficients.
• When validated against the most similar construct with a criterion of r > 0.50, only 10 out of 42 instruments demonstrated validity.