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Letter to the editor regarding "Clinical effectiveness and safety of powered exoskeleton-assisted walking in patients with spinal cord injury: systematic review with meta-analysis"

Authors Dijkers MP, Akers KG, Galen SS, Patzer DE, Vu PT

Received 20 October 2016

Accepted for publication 1 November 2016

Published 29 November 2016 Volume 2016:9 Pages 419—421


Checked for plagiarism Yes

Editor who approved publication: Dr Scott Fraser

Marcel P Dijkers,1 Katherine G Akers,2 Sujay S Galen,3 Diane E Patzer,4 Phuong T Vu4

1Department of Physical Medicine and Rehabilitation, Wayne State University, Detroit, 2Shiffman Medical Library, Wayne State University, Detroit, 3Physical Therapy Program, Wayne State University, Detroit, 4Center for Spinal Cord Injury Recovery, Rehabilitation Institute of Michigan, Detroit, MI, USA

In the article “Clinical effectiveness and safety of powered exoskeleton-assisted walking in patients with spinal cord injury: systematic review with meta-analysis”, published in the March issue of Medical Devices: Evidence and Research, Miller et al1 present a meta-analysis of the clinical effectiveness and safety of powered exoskeletons for spinal cord injury (SCI) patients. A close examination of this article shows surprising coincidences, in that two primary studies (references 25 and 33 in the reference list) report the same proportions and 95% confidence intervals (CIs) of subjects able to ambulate with an exoskeleton without assistance (Figure 2 of the study), and two different primary studies (references 26 and 28) report the same mean and 95% CIs for the distance (in meters) walked in a 6-minute walk test (Figure 4 of the study).
Authors' reply
Larry E Miller,1 Angela K Zimmermann,1 William G Herbert1,2

1Miller Scientific Consulting, Inc, Asheville, NC, 2Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg,
We appreciate the letter from Dijkers et al. The issue of duplicate publication in systematic reviews is important and is often difficult to identify in practice. In the current systematic review, identification of common patients was facilitated by reporting of individual patient characteristics in most included papers. Based on such data, one can uniquely identify a patient with high likelihood. That is, the chances that any two patients would exactly match on all baseline characteristics are exceedingly low. As with all systematic reviews that we perform, data are extracted to identify manuscripts that potentially reported on common patients. Based on the data extracted, we found no evidence of this occurrence. In studies performed by same author groups, we identified patient and/or study design characteristics that were distinctly different among all studies.
View the original paper by Miller and colleagues.

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