Abstract
Objective
To determine the construct validity and test re-test reliability of the Six-minute Walk Test (6MWT) and Incremental Shuttle Walk Test (ISWT) in the sub-acute recovery phase following mild-to-moderate severity stroke.
Participants
40 stroke patients (mean age: 68.27 years, SD: 13.48) of median National Institutes of Health Stroke Scale (NIHSS) score 1.2 (range: 0 to 8) within six months of stroke.
Method
Each participant completed one Incremental Cycle Test (ICT) followed by two ISWT and two 6MWT in a randomised order. Pearson’s Correlation Coefficients were used to determine the validity and Bland Altman plots were used to determine the test re-test reliability.
Results
The Incremental Cycle Test (ICT) was positively correlated with the ISWT (r = 0.59, 95% confidence intervals 0.35 to 0.76, P = 0.001) and the 6MWT (0.55, 0.35 to 0.71, P < 0.001). The correlation of the ICT with the ISWT and 6MWT was higher for the 17 patients with no residual (ISWT: r = 0.79, P < 0.001; 6MWT: 0.826, P < 0.001) compared to mild-to-moderate neurological impairment (ISWT: r = 0.45, P = 0.03; 6MWT: r = 0.38, P = 0.08). Test–retest reliability for both the ISWT and the 6MWT showed that there was some variability between the first and second tests with a better performance on the second test.
Conclusion
The ISWT and 6MWT have a significant, modest correlation with the ICT for stroke patients in the sub-acute recovery phase. The ISWT and 6MWT are not strongly correlated with ICT (VO2 peak) in a stroke population that is disabled. The test–retest reliability of the ISWT and 6MWT indicated that two tests may be needed to accurately assess an individual’s capabilities.
Abbreviations:
6MWT (Six minute Walk Test), ISWT (Incremental Shuttle Walk Test), NIHSS (National Institute of Health Stroke Scale), VO2 Peak (peak oxygen uptake), VO2 Max (maximum oxygen uptake), ICT (Incremental Cycle Test), CI(confidence interval), CRf (cardiorespiratory fitness), NYHA (New York Heart Association), ACSM (American College of Sports Medicine), BMI (Body Mass Index), MHR (maximum heart rate), MBP (maximum blood pressure), Rpm (revs per minute), WRI (work rate intensity), RER (Respiratory Exchange Ratio)
Citation
The validity and reliability of the Incremental Shuttle Walk Test and Six-minute Walk Test compared to an Incremental Cycle Test for people who have had a mild-to-moderate stroke