Patient Demographic Factors Impact KOOS JR Response Rates for Total Knee Arthroplasty Patients

The Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) is a validated patient-reported measure for assessing pain and function following total knee arthroplasty (TKA). This study investigates how patient demographic factors (i.e., age, sex, and race) correlate with KOOS JR response rates. This was a retrospective cohort study of adult, English-speaking patients who underwent primary TKA between 2017 and 2023 at an academic institution. KOOS JR completion status-complete or incomplete-was recorded within 90 days postoperatively. Standard statistical analyses were performed to assess KOOS JR completion against demographic factors. Among 2,883 total patients, 70.2% had complete and 29.8% had incomplete KOOS JR questionnaires. Complete status (all p < 0.01) was associated with patients aged 60 to 79 (71.8%), white race (77.6%), Medicare (81.7%), marriage (76.8%), and the highest income quartile (75.7%). Incomplete status (all p < 0.001) was associated with patients aged 18 to 59 (64.4%), Medicaid (82.4%), and lower income quartiles (41.6% first quartile, 36.8% third quartile). Multiple patient demographic factors may affect KOOS JR completion rates; patients who are older, white, and of higher socioeconomic status are more likely to participate. Addressing underrepresented groups is important to improve the utility and generalizability of the KOOS JR.