Power estimation for non-standardized multisite studies
A concern for researchers planning multisite studies is that scanner and T1-weighted sequence-related biases on regional volumes could overshadow true effects, especially for studies with a heterogeneous set of scanners and sequences. Current approaches attempt to harmonize data by standardizing hardware, pulse sequences, and protocols, or by calibrating across sites using phantom-based corrections to ensure the same raw image intensities. We propose to avoid harmonization and phantom-based correction entirely. We hypothesized that the bias of estimated regional volumes is scaled between sites due to the contrast and gradient distortion differences between scanners and sequences. Given this…
Corrigendum to “Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): Standardized protocol and reference values” [Pain 123 (2006) 231–243]
a Institute of Physiology and Pathophysiology, Johannes Gutenberg-University, Mainz, Germany b Department of Neurology, Johannes Gutenberg-University, Mainz, Germany c Division of Neurological Pain Research and Therapy, Department of Neurology, University of Kiel, Germany d Department of Pain Management, BG Kliniken Bergmannsheil, Ruhr University Bochum, Germany e Department of Neurology, Technische Universitat Munchen, Germany f Department of Anaesthesiology, Ludwig-Maximilians-Universitat Munchen, Germany g Institute of Medical Psychology and Behavioural Neurobiology, University of Tubingen, Germany h Department of Neurology, University of Freiburg, Germany i Department of Clinical and Co…
Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): Standardized protocol and reference values
The nationwide multicenter trials of the German Research Network on Neuropathic Pain (DFNS) aim to characterize the somatosensory phenotype of patients with neuropathic pain. For this purpose, we have implemented a standardized quantitative sensory testing (QST) protocol giving a complete profile for one region within 30 min. To judge plus or minus signs in patients we have now established age- and gender-matched absolute and relative QST reference values from 180 healthy subjects, assessed bilaterally over face, hand and foot. We determined thermal detection and pain thresholds including a test for paradoxical heat sensations, mechanical detection thresholds to von Frey filaments and a 64 …