Assessing Minimal Detectable Changes and Test-Retest Reliability of the Timed Up and Go Test and the 2-Minute Walk Test in Patients With Total Knee Arthroplasty.

BACKGROUND: Two-minute walk test (2MWT) and the Timed Up and Go test (TUG) are simple, quick, and can be applied in a short time as part of the routine medical examination. They were shown to be reliable and valid tests in many patient groups. The aims of the present study were: (1) to determine test-retest reliability of data for the TUG and 2MWT and (2) to determine minimal detectable change (MDC) scores for the TUG and 2MWT in patients with TKA. METHODS: Forty-eight patients with total knee arthroplasty, operated by the same surgeon, were included in this study. Patients performed trials for TUG and 2MWT twice on the same day. Between the first and second trials, patients waited for an hour on sitting position to prevent fatigue. RESULTS: The TUG and 2MWT showed an excellent test-retest reliability in this study. Intraclass correlation coefficient [ICC(2,1)] for TUG and 2MWT were 0.98 and 0.97, respectively. Standard error of measurement and MDC95 for TUG were 0.82 and 2.27, respectively. Standard error of measurement and MDC95 for 2MWT were 5.40 and 14.96, respectively. CONCLUSION: The TUG and 2MWT have an excellent test-retest reliability in patients with TKA. Clinicians and researchers can be confident that changes in TUG time above 2.27 seconds and changes in 2MWT distances above 14.96 meters, represent a "real" clinical change in an individual patient with TKA. We, therefore, recommend the use of these 2 tests as complementary outcome measures for functional evaluation in patients TKA.

Reliability of 4-meter and 10-meter walk tests after lower extremity surgery.

PURPOSE: To investigate the test-retest reliability of the 4-meter walk test (4 MWT) and 10-meter walk test (10 MWT) in patients undergoing lower extremity surgery during inpatient rehabilitation. METHOD: In all, 102 patients with total hip arthroplasty (THA), total knee arthroplasty (TKA), lower extremity fracture (LEF) and soft tissue operation were recruited. Patients performed two 4 MWT and two 10 MWT trials on the same day. The same researcher performed all the measurements to avoid inter-rater variability. RESULTS: The 4 MWT and 10 MWT were shown to have excellent test-retest reliability. The ICCs for the 4 MWT and 10 MWT were found as 0.94 and 0.95, respectively. The SEMs for the 4 MWT and 10 MWT were 2.0 and 5.5 seconds, respectively. The smallest real difference at the 95% confidence level (SRD95) was 5.5 seconds for the 4 MWT and 12.2 seconds for 10 MWT and SRD95 percentage was 31.2 for the 4 MWT and 28.5 for the 10 MWT. CONCLUSION: Both the 4 MWT and the 10 MWT have excellent reliability in patients undergoing lower extremity surgery such as TKA, THA, LEF and soft tissue operation during inpatient rehabilitation. Clinicians and researchers can be confident that changes above the SRD95s for the different patient groups, for both sexes and with regard to weight-bearing status, represent a real clinical change in rehabilitation process. Implications for Rehabilitation The 4 MWT and the 10 MWT are simple methods and were also shown to be reliable measurement methods in many patient groups. This study illustrates that the test-retest reliability of the 4 MWT and 10 MWT are excellent in patients undergoing lower extremity surgery during inpatient rehabilitation (ICC: 0.94 for 4 MWT, ICC: 0.95 for 10 MWT). Clinicians and researchers can be confident that changes above the SRD95s for the different patient groups, for both sexes and with regard to weight-bearing status represent a real clinical change in rehabilitation process.