The association between urgency for knee arthroplasty and discordance between perceived and actual function

Purpose Discordance between self-reported and performance-based outcomes may reflect psychological well-being of patients suffering from osteoarthritis (OA). The purpose of this study was to examine the association between pattern of discordance and characteristics of candidates for knee arthroplasty.Methods This was a cross-sectional study, conducted at a Rapid Access Clinic of a tertiary care centre. Discordance was calculated between the normalised scales of a self-reported outcome measure, the Lower Extremity Functional Score (LEFS), and the 40-meter fast-paced walk test (FPWT). Optimal Screening for Prediction of Referral and Outcome Yellow Flags (OSPRO-YF) measured psychosocial well-being, and the Severity Scoring System (SSS) determined disease severity and urgency for surgical consultation.Results Eighty-five consecutive patients [49 females (58%), 36 males (42%), mean age = 68 years, SD = 8] participated in the study. Higher discordance was associated with lower SSS total score (t83 = −4.20, p < 0.0001), which determined disease severity and less urgency for surgery (t83 = −2.92, p = 0.005). Female patients showed less favourable discordance scores (t83 = 3.21, p = 0.002). Better psychosocial wellbeing was associated with higher discordance (t83 = −2.20, p = 0.030). Disease severity/surgical urgency and gender remained significant in the multivariable analyses.Conclusions Higher discordance in a positive direction is associated with less severity of osteoarthritis/surgical urgencyand male gender. Presence of positive discordance is reflective of the patient’s ability to better navigate the experience of disability and additional research is needed to identify other important factors at play.