Preoperative Expectations and Functional Scores for Primary Total Knee Arthroplasty Vary Based on Health Literacy

Health literacy (HL) is essential for managing medical conditions, including primary total knee arthroplasty (TKA). We evaluated whether HL was related to patient-reported preoperative expectations for improvement and baseline patient-reported functional scores.

Elective primary TKAs (n = 345) performed at an academic hip and knee center were prospectively enrolled in a study evaluating mediators of patient-reported outcomes. The sample consisted of 68% women, with an average age and body mass index of 67 years (range, 42 to 90) and 36 (range, 18 to 70). Validated preoperative measures included a single-item assessment of HL, Knee Society expectations for pain and functional improvement, Knee Injury and Osteoarthritis (KOOS JR) joint health, and Patient-Reported Outcomes Measurement Information System (PROMIS) global mental and physical health. Multivariable analyses controlling for covariates were conducted.

Higher HL was reported by 77% of patients, with 23% reporting lower HL. Higher HL was associated with higher mean expectation scores for pain relief (P = 0.014) and improvement in activities of daily living (P = 0.009) and recreational, sports, and leisure activities (P < 0.001). These differences were reflected in a higher mean total expectations score (P = 0.001). The mean PROMIS global mental (P < 0.001) and physical (P = 0.010) health were significantly higher in patients who have higher HL. The mean KOOS JR scores did not differ based on higher versus lower HL (P = 0.57). HL remained a significant mediator of preoperative functional scores in multivariable analyses.

Study findings suggest that lower HL correlated with lower preoperative expectations and PROMIS baseline scores, despite equally poor KOOS JR scores, indicating equal knee dysfunction between groups. These differences may influence patient-reported postoperative outcomes, which will soon be tied to reimbursement. Preoperative patient education may benefit from a better understanding of individual differences in HL.