Use of Response Shift to Improve Agreement between Patient-Reported and Performance-Based Outcomes in Knee Patients

Abstract

The purpose of this study was to determine whether the implementation of performance-based tasks (PBTs) prior to completion of patient-reported outcome measures (PROs) would create a change, or a response shift, in PROs in patients with knee injuries. A randomized controlled trial was implemented to examine the effectiveness of a response-shift based interventions to enhance the correlation between PBTs and PROs. Participants (n=20) were knee-injured patients who were removed from activity for a minimum of 1-week. Participants were randomly assigned to complete PBTs (intervention) or to watch videos detailing an injury prevention program (control). The International Knee Documentation Committee Subjective Form (IKDC) and the Knee Injury and Osteoarthritis Outcome Score Recreational and Sports Subscale (KOOSsports) were completed both pre- and post-testing. The independent variable was Group. Dependent variables included raw change scores and absolute change scores on the IKDC and KOOSsports. Mann-Whitney U tests were used to examine between Group differences. Changes in PRO scores were not considered statistically significant or clinically meaningful (IKDC Raw p = 0.14, Absolute p = 0.74; KOOSsports Raw p = 0.85 Absolute p = 0.32). Implementation of PBTs prior to PROs did not induce a response shift. PROs may better evaluate symptoms and/or confidence in a patient, while PBTs evaluate physical function.