We appreciate the comments from Morone et al on our article.
1We agree that there may be aspects that are not revealed by a correlation coefficient and that an analysis of the residuals may provide further insights. Our article already provides a figure showing linear regression lines based on the individual data points. As suggested in Morone's letter, we have now further created residual plots to look at whether the variations in residuals plotted against the predicted walking speed are systematic or not. As shown in figure 1, the variations in residuals are nonsystematic in our group of stroke patients. In the multiple sclerosis (MS) patients, the residual plot bears a slight resemblance to an inverted U-shape, indicating that the relation between the 2 tests might be better represented by a curvilinear model. However, fitting to a second-order polynomial instead of a linear regression would only minimally increase the predictive power of the fit (r=.97 vs .95). The residuals of the control group do not seem to vary systematically.
- Dalgas U.
- Severinsen K.
- Overgaard K.
Relations between 6 minute walking distance and 10 meter walking speed in patients with multiple sclerosis and stroke.
Arch Phys Med Rehabil. 2012; 93: 1167-1172
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Archives of Physical Medicine and Rehabilitation
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Relations between 6 minute walking distance and 10 meter walking speed in patients with multiple sclerosis and stroke.Arch Phys Med Rehabil. 2012; 93: 1167-1172
- ATS statement: guidelines for the six-minute walk test.Am J Respir Crit Care Med. 2002; 166: 111-117
- Assessing walking disability in multiple sclerosis.Mult Scler. 2012; 18: 914-924
© 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
ScienceDirectAccess this article on ScienceDirect
- Relations or Agreement Between 6 Minute Walking Distance and 10 Meter Walking Speed?Archives of Physical Medicine and RehabilitationVol. 93Issue 10
- PreviewWe read with great interest the article by Dalgas et al.1 Dalgas found a strong correlation between walking speeds evaluated during the 10 meter walk test and the 6 minute walk test (6MWT) in patients affected by chronic stroke and in patients with multiple sclerosis (MS), whereas a weaker correlation was found in healthy subjects.