The reliability of walking tests in people with claudication

To contrast the reliability of the 6-min walking test (6MW) with that of the shuttle walking test (SWT) in patients with intermittent claudication attributable to peripheral obstructive arterial disease (POAD), and to examine the relationships of the walking tests, medical outcomes, and hemodynamic variables.

Twenty-three patients were randomly assigned to perform both walking tests on two different occasions. Total distance walked (DW), time of pain onset (PO), and time of limiting claudicating symptom (TLS) were analyzed.

The reliability coefficients (ICC) generated with the 6MW for DW, PO, and TLS were 0.84, 0.81, and 0.63, respectively, and the coefficients of variation (CV) across trials were 18, 31.8, and 20.3%, respectively. With the SWT, the ICCs were 0.95, 0.72, and 0.90 for each variable, respectively, whereas the CV was 10.9% for DW, 26.8% for PO, and 9.1% for TLS. There was a significant correlation between DW and double product with the SWT (r=0.51, P=0.01), but there was no correlation with the 6MW.

Both the 6MW and the SWT are reliable walking tests for claudicant patients. However, the reliability coefficients obtained with the SWT are higher, the measurements are less variable, and there were better associations between this walking test and hemodynamic variables.