Defining Failure in Primary Total Joint Arthroplasty: The Minimal Clinically Important Difference for Worsening Score

Background: We define the value of the Minimal Clinically Important Difference for Worsening (MCIDW) for Patient-Reported Outcomes Measurement Information System Physical Function short form 10-a (PROMIS-PF-10a) score for primary total joint arthroplasty (TJA) of the hip and knee and describe the risk factors for patients scoring worse than the MCID-W. Methods: This retrospective study was performed using 3414 primary TJA patients. PROMIS-PF-10a scores were collected at the preoperatively and postoperatively, and patients were classified based on reaching Minimal Clinically Importance Difference for Improvement (MCID-I), MCID-W, or "no significant change" after TJA (scores betweexn MCID-W and MCID-I). MCID-W and MCID-I values were determined by a distribution method. The association between numerous variables and scoring worse than the MCID-W of PROMIS-PF-10a was then evaluated through multiple logistic regression. A threshold for preoperative PROMIS-PF-10a score predicting decline past MCID-W was determined using the You den index and receiver operating characteristic curve. Results: The MCID-W for TJA was -1.89. Notably, increasing length of stay (odds ratio [OR] 1.073, 95% confidence interval [CI] 1.029-1.119, P < .001) and increasing preoperative PROMIS-PF-10a scores (OR 1.117, 95% CI 1.091-1.144, P < .001) were associated with increased likelihood of decline past the MCID-W of the PROMIS-PF-10a for TJA compared with patients who achieved the MCID-I. A community hospital with a dedicated joint replacement center was associated with a decreased risk for decline past the MCID-W (OR 0.601, 95% CI 0.402-0.899; P = .013). Conclusion: We described the MCID-W value (-1.89) for the PROMIS-PF-10a questionnaire for knee and hip TJA and associated patient-and hospital-level risk factors for failure after TJA. Healthcare funding initiatives should be directed toward modifiable factors associated with clinically significant worse outcomes after TJA. (C) 2021 Elsevier Inc. All rights reserved.