Performance of the Patient-Reported Outcome Measurement Information System in Patients With Patellofemoral Instability

BACKGROUND: The Patient-Reported Outcome Measurement Information System (PROMIS) was developed to improve patient-reported outcome measures (PROMs) and administration through a computer adaptive test (CAT). The PROMIS physical function-CAT (PF-CAT) has not been investigated in patients with patellofemoral instability (PFI). PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate the construct validity of the PROMIS PF-CAT with previously validated tools for measuring PROMs in patients with a diagnosis of PFI. We hypothesized that the PF-CAT will have the strongest correlations with other PROMs that evaluated PF as well as moderate correlations with PROMs that measured other health domains. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Patients enrolled in this study who underwent operative intervention for PFI completed the following evaluations preoperatively: PROMIS PF-CAT, 36-Item Short Form Health Survey (SF-36), Knee injury and Osteoarthritis Outcome Score (KOOS), EuroQol-5 dimensions (EQ-5D), and Kujala Anterior Knee Pain Scale (AKPS). Correlation coefficients and the percentage of patients achieving the highest and lowest possible outcome score of each instrument were calculated to assess floor and ceiling effects. Statistical significance was defined as P < .05. RESULTS: In total, 91 participants (63.7% females; mean age, 20.1 ± 7.2 years) completed the questionnaires. PF-CAT had the lowest number of questions (4.3 ± 1.1). The strongest correlations were between the PF-CAT and SF-36 PF subscale (r = 0.78; P < .01), AKPS (r = 0.68; P < .01), and KOOS Activities of Daily Living subscale (r = 0.68; P < .01). Correlation was moderate between the PF-CAT and the KOOS subscales of Sports/Recreation (r = 0.58; P < .01), Quality of Life (r = 0.53; P < .01), and Symptoms (r = 0.47; P < .01). The PROMIS PF-CAT demonstrated no floor or ceiling effects. CONCLUSION: In patients with PFI, construct validity of the PROMIS PF-CAT was supported by strong correlations demonstrated between the PF-CAT and PROMs evaluating PF and moderate correlations with those assessing other health domains. Our results demonstrated a low respondent burden and no floor or ceiling effects associated with the PROMIS PF-CAT. The PROMIS PF-CAT may be considered a beneficial alternative to previously established PF PROMs for preoperative evaluation of patients with PFI.