Abstract
Objective
The incremental shuttle walking test (ISWT) is widely used to assess patients with chronic obstructive pulmonary disease. We hypothesised that it would be an appropriate tool to assess patients with coronary heart disease following coronary artery bypass grafts. We therefore explored the reproducibility, validity and sensitivity of the ISWT following rehabilitation.
Design
Participants completed three ISWTs and an incremental treadmill test over 7 days. Eleven patients repeated the ISWT following rehabilitation.
Setting
Cardiac rehabilitation department.
Participants
Thirty-nine patients, 34 of whom were male, with a mean age of 61.2 years (S.D. 8.5), 6–8 weeks after coronary artery bypass graft surgery.
Main outcome measures
Maximum oxygen uptake (
O2
peak, ml/min/kg) and ISWT.
Results
Mean (S.D.) distances for the three ISWTs were 448m (137.8), 487m (147.6) and 481m (138.2). There was no statistically significant difference between the three ISWTs. The mean difference between Tests 1 and 2 was 42.8m (95% confidence interval 59.1–26.5m) compared with 1.7m (95% confidence interval −1.86–5.29
) between Tests 2 and 3. The mean 
O2peak was 21.0 (S.D. 4.5) ml/min/kg. There was a significant relationship between the results for the three ISWTs and 
O2peak (r=0.79, r=0.86 and r=0.87 for Tests 1–3, respectively). Following rehabilitation, there was a significant increase in the distance walked; the mean difference between the second ISWT and the post-rehabilitation ISWT was 81.8m (95% confidence interval 53.2–110.4, P<0.001).
Conclusions
The ISWT correlates well with 
O2peak and is a reliable measure of cardiorespiratory fitness in this population after one practice walk.
Citation
Reproducibility and validity of the incremental shuttle walking test in patients following coronary artery bypass surgery
S.J. Fowler, S.J. Singh, S. Revill
Physiotherapy - March 2005 (Vol. 91, Issue 1, Pages 22-27, DOI: 10.1016/j.physio.2004.08.009)