Minimal Clinically Important Difference of the Timed Up and Go Test, 10-Meter Walk Test, and 2-Minute Walk Test in Patients in the Acute Phase After Total Hip Arthroplasty.

Abstract

The recovery of mobility and ambulation are primary rehabilitative goals to allow for an early and safe discharge after total hip arthroplasty (THA). Although the Timed Up and Go test (TUG), 10-Meter Walk Test (10MWT), and 2-Minute Walk Test (2MWT) are widely used performance-based tests to assess functional progress and readiness for discharge, their Minimal Clinically Important Difference (MCID) has never been investigated in the early phase after THA. The study aimed to determine the MCID of the TUG, 10MWT, and 2MWT in patients in the early postoperative phase after THA. This prospective, single-group observational study included 100 inpatients who performed TUG, 10MWT, and 2MWT on the first and third postoperative days after THA. After the second evaluation session, participants rated their perceived functional improvement using a 15-point Global Rating of Change scale. MCIDs were estimated using anchor-based (within-patient, between-patient, and ROC curve) and distribution-based methods. The MCID estimates revealed high variability across methods within each test (TUG: 3.7 to 9.0 seconds; 10MWT: 0.06 to 0.25 meters/second; 2MWT: 3.3 to 33.5 meters). The TUG revealed acceptable discriminative ability for the detection of meaningful improvements (Area Under the Curve (AUC) = 0.73; 95% confidence interval (CI): 0.62 to 0.82). The 10MWT (AUC = 0.64) and 2MWT (AUC = 0.55) did not reveal an acceptable discriminative threshold, being AUC less than 0.70. The TUG revealed higher discriminative ability in identifying clinically meaningful functional improvements compared to walking performance tests. These MCID values provide useful reference points for clinical practice and research.