Reliability of the 6-min walk test after total knee arthroplasty.
OBJECTIVE
The 6-min walk test is a simple clinical outcome measure, which has been used frequently to assess functional performance in many different patient groups, including patients with total knee arthroplasty (TKA). The 6-min walk test measures the maximal distance a subject is able to walk in 6 min. The reliability is unknown in patients with TKA. Therefore, the purpose of the study was to assess the reliability of the 6-min walk test in patients with recent TKA.


METHODS
Thirty-four patients with TKA performed 2 test trials the same day, separated by a 1-h seated rest. To assess reliability, intra-class correlation coefficient (ICC2,1), standard error of measurement (SEM), and smallest real difference (SRD) were calculated.


RESULTS
The patients walked on average 14.1 m longer at the second (397.2 m) compared to the first (383.1 m) test trial. The ICC2,1, SEM, and SRD were 0.97, 13.0, and 36.1 m, respectively.


CONCLUSIONS
The intra-tester reliability of the 6-min walk test was high in patients with TKA. The thresholds of the 6-min walk test to detect a real change are acceptable in research (SEM) and clinical settings (SRD). We recommend that the longest distance walked in 2 supervised test trials should be used.
Clinical Research Centre (136), Copenhagen University Hospital, Hvidovre, Kettegaard Allé 30, 2650, Hvidovre, Denmark, tlj26@hotmail.com.
Thomas Linding
TL
Jakobsen
Henrik
H
Kehlet
Thomas
T
Bandholm
D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D017063:Outcome Assessment, Health Care; D015203:Reproducibility of Results