PROMIS physical function underperforms psychometrically relative to American Shoulder and Elbow Surgeons score in patients undergoing anatomic total shoulder arthroplasty

Abstract

The purpose of this study was to evaluate the psychometric properties of the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function computer adaptive test (PF-CAT) relative to the American Shoulder and Elbow Surgeons (ASES) score in patients with glenohumeral osteoarthritis undergoing primary anatomic total shoulder arthroplasty (TSA). A retrospective study of an institutional TSA registry was performed. Preoperative PROMIS PF-CAT and ASES scores were collected. Floor and ceiling effects were determined, and convergent validity was established through Pearson correlations. Rasch partial credit modeling was used for psychometric analysis of the validity of PF-CAT and ASES question items. Person-item maps were generated to characterize the distribution of question responses along the latent dimension of shoulder disability. Responses from 179 patients (184 shoulders) were included. PF-CAT had a moderate correlation to ASES (r = 0.487; P < .001), with no floor or ceiling effects; ASES had a 1.1% floor effect and no ceiling effect. With iterative Rasch model item-reduction analysis eliminating poorly fitting question items, all possible PF-CAT items were eliminated after 6 iterations. With ASES, just 1 function question item was dropped. Person-item maps showed ASES to be superior to PROMIS PF-CAT psychometrically, with sequential and improved coverage of the latent dimension of shoulder disability. Despite moderate correlation with ASES, PROMIS PF-CAT demonstrated inferior validity and psychometric properties in patients undergoing TSA. PF-CAT should not replace the ASES in this population of patients.