Convergent Validity of the Patient-Reported Outcomes Measurement Information System's Physical Function Computerized Adaptive Test for the Knee and Shoulder Injury Sports Medicine Patient Population

Abstract

To evaluate the convergent validity, precision, and completion times for the Physical Function Computerized Adaptive Test (PF-CAT) in a sports medicine patient population relative to standard measures of knee and shoulder function. We reviewed all patient visits from April through September 2014 with either knee or shoulder complaints from a university-based sports medicine clinic, during which PF-CAT, Single Assessment Numerical Evaluation (SANE), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons (ASES) outcome scores for shoulder patients and PF-CAT, SANE, and International Knee Documentation Committee (IKDC) scores for knee patients were obtained, with an initial visit or one follow-up visit included in the study. Spearman correlation was used to evaluate pairwise agreement among scores. The McNemar χ2 test was used to evaluate a difference in the number of times floor and ceiling values occurred. Wilcoxon signed rank tests were used to compare differences in completion times. In total, 415 shoulder and 450 knee clinical evaluations qualified for inclusion in the study. A high correlation was found between IKDC and PF-CAT scores (r= 0.75, P < .0001), and a moderately high correlation was found between PF-CAT and both SST (r= 0.68, P < .0001) and ASES (r= 0.63, P < .0001) scores. Maximum differences in the sum of floor-ceiling values versus the PF-CAT were 15% for the SST (P < .0001), 2.5% for the ASES (ceiling only, P= .0133), and 5.8% for the shoulder SANE (floor P= .0012, ceiling P= .0269). The PF-CAT had values of 0.4% for the shoulder and 0.6% for the knee. Zero percent of IKDC scores but 6.9% of knee SANE scores hit floor or ceiling values (floor P= .0019, ceiling P= .0007). The PF-CAT median completion time was lower at 55seconds versus 268seconds for the IKDC assessment (P < .0001), whereas shoulder patients' times were 61, 139, and 116seconds for the PF-CAT, SST, and ASES evaluation, respectively (P < .0001). The PF-CAT showed a high correlation with IKDC scores and a moderately high correlation with ASES and SST outcomes. The PF-CAT takes significantly less time to complete and exhibits improved or similar floor and ceiling effects in comparison to IKDC, SST, and ASES scores. The PF-CAT can be used in evaluating sports medicine knee and shoulder patients. Level III, cross-sectional study.