ABSTRACT
OBJECTIVES: To examine the methodological basis behind the conclusions of patient-reported outcome measure (PROM) validation studies. STUDY DESIGN AND SETTING: A systematic review was performed on surgical studies evaluating the measurement properties of a PROM between June 1 and December 31, 2021. The quality of the validity subfield evaluation in the studies was assessed according to the consensus-based standards for the selection of health measurement instruments checklist. Nine validity subfields were assessed. RESULTS: The median sample size of the 87 included studies was 125 (interquartile range: 99-226), and 22 of the studies (25%) had an insufficient sample size according to the consensus-based standards for the selection of health measurement instruments checklist. For the nine validity subfields, the mean number of correctly assessed subfields was 3.6 (standard deviation: 1.5). In 68 of the studies (78%), the conclusion determined the PROM to be valid. In these studies, the mean number of evaluated validity subfields was 3.8 (standard deviation: 1.4). None of the studies reported that the PROM was not valid. CONCLUSION: The empirical basis of the conclusions drawn in studies investigating the measurement properties of a PROM is often deficient. PROM studies were often performed with insufficient sample sizes and focused on only a few validity subfields, calling into question the deterministic conclusions that a PROM is valid.
