Test-Retest Reliability of the 6-Minute Walk Test on a 20 × 3.5 m Circuit in Parkinson’s Disease

Background: The 6-minute walk test (6MWT) has been used to measure the level of functional capacity in people with Parkinson's disease (PD). However, the use of a non-linear circuit has not yet been investigated. Thus, the aim of this study was to evaluate the test-retest reliability of the 6-minute walk test in a rectangular circuit in people with PD. Methods: Forty-two people with PD (men=27, women=15), mean age 66±9.61 years, partici-pated. Each patient performed the 6MWT on 2 test days separated by 1 week, walking at a constant speed on a 20m x 3.5m circuit. Test-retest reliability was assessed using the intraclass correlation coefficient and the Student's t-test was applied to determine whether there were statistically significant differences between the test and the retest. Results: The ICC values for the total sample were excellent (< 0.90) in both men and women. In addition, they had similar reliability, although slightly higher in women. The results showed that, for the total sample, a smallest true difference (SRD) < 17% can be considered as a true change for this procedure. The standard error of measurement (SEM) percentage was 6.1. Conclusions: The 6-minute walk test (6MWT), performed on a rectangular circuit, is a reliable and valid tool for assessing functional capacity in PD patients.