Criterion validity

Criterion validity assesses how well the scores from a patient-reported outcome measure (PROM) align with a recognised “gold standard” measure of the same or a closely related construct. There are two types of criterion validity:

1. Concurrent validity: Evidenced by a strong correlation between the PROM’s scores and the “gold standard” scores when both are measured at roughly the same time.
2. Predictive validity: Evidenced by a strong correlation between the PROM’s scores and the “gold standard” scores when the “gold standard” is measured at a later point in time, indicating the PROM’s ability to predict future outcomes as measured by the criterion.

The criterion validity is only as good as the validity of the “gold standard” it is compared against.