Construct validity is the evidence such as documentation of empirical findings that support predefined hypotheses on the expected associations among measures similar or dissimilar to the measured PRO. There are two main types of construct validity: (1) Convergent validity refers to whether the outcomes of an instrument correspond to that of another instrument measuring the same or similar constructs. For example, you would expect people who report a high utility on the EQ-5D to also report a high utility on the SF-36 (i.e. their responses to both instruments should be highly correlated). (2) Discriminant validity is essentially the opposite, referring to whether the outcomes of two instruments measuring a theoretically unrelated construct are very weakly or negatively correlated. For example, if you were measuring introversion, you would anticipate that the outcome of an instrument designed to measure introversion would be negatively correlated with that produced by an instrument designed to measure extroversion.
How to cite: Construct Validity [online]. (2016). York; York Health Economics Consortium; 2016. https://yhec.co.uk/glossary/construct-validity/