Letter by Iosa et al Regarding Article, “Reliability and Validity of Bilateral Ankle Accelerometer Algorithms for Activity Recognition and Walking Speed After Stroke”

Abstract

To the Editor: We read with great interest the article of Dobkin and colleagues1 recently published in Stroke . They proposed a method that could be very helpful to assess walking speed and mobility-related activity of people with stroke in the home and in the community. This method has the advantages2 of using 2 wearable, wireless, light, and low-cost triaxial accelerometers located above each ankle, and of using Bayesian Recognition Algorithms to analyze their signals. However, in our opinion, statistical analyses performed by the authors may be inappropriate, risking belittling their work. They computed the Pearson correlation coefficient ( r ) to assess the reliability and validity of their method. In many studies, r has been computed to assess the validity of a new measure.3 But the correlation coefficient between 2 variables ( x,y ) measures the strength of their linear …