Determining the minimal clinically important difference for EQ-5D-5L scores in patients undergoing primary total knee arthroplasty

Total Knee Arthroplasty (TKA) is a common procedure for knee osteoarthritis, but the Minimal Clinically Important Difference (MCID) for the EQ-5D-5L scale in TKA patients is not established. This study aims to determine the MCID for EQ-5D-5L in TKA patients. A prospective study with 573 TKA patients was conducted. EQ-5D-5L were completed preoperatively and 1-year postoperatively. The MCID was calculated using anchor-based, distribution-based, and ROC curve methods. The MCID for the EQ-5D-5L index was 0.103 (anchor-based), 0.099 (distribution-based), and 0.09 (ROC). For EQ-VAS, the MCID values were 8.55 (anchor-based), 7.315 (distribution-based), and 6.912 (ROC). Significant improvements in both scores were observed postoperatively ( p < 0.001). The MCID values for EQ-5D-5L, determined by calculation method, offer complementary insights into recovery. These findings provide benchmarks to optimize postoperative care and enhance patient outcomes.