Glossary Term
Construct Validity
An OMERACT measurement property that assesses whether the scores produced by an instrument behave as expected based on existing knowledge of the domain or construct it is intended to measure. It evaluates whether the instrument’s scores are consistent with a priori hypotheses about expected relationships with other measures, patient groups, or clinical characteristics.
Construct validity is commonly assessed by comparing the instrument with measures of similar or related constructs, where stronger relationships may be expected, and measures of different or unrelated constructs, where weaker relationships may be expected. The expected direction and strength of these relationships should ideally be specified before the results are examined.
In simple terms: Construct validity asks, “Do the scores make sense?”
Examples
A new questionnaire is developed to measure fatigue in people with lupus. To demonstrate construct validity, researchers hypothesize that higher scores on the new tool will correlate strongly with existing validated fatigue scales (convergent validity) and only weakly with unrelated constructs such as joint swelling (discriminant validity). If the results match these hypotheses, it supports the instrument’s construct validity.