The DOI matches its Crossref record; 36 of the 36 references it cites were found in a registry or an index.
Rethinking Clinical Trials of Transcranial Direct Current Stimulation: Participant and Assessor Blinding Is Inadequate at Intensities of 2mA
Open accessAbstract
BACKGROUND: Many double-blind clinical trials of transcranial direct current stimulation (tDCS) use stimulus intensities of 2 mA despite the fact that blinding has not been formally validated under these conditions. The aim of this study was to test the assumption that sham 2 mA tDCS achieves effective blinding. METHODS: A randomised double blind crossover trial. 100 tDCS-naïve healthy volunteers were incorrectly advised that they there were taking part in a trial of tDCS on word memory. Participants attended for two separate sessions. In each session, they completed a word memory task, then received active or sham tDCS (order randomised) at 2 mA stimulation intensity for 20 minutes and then repeated the word memory task. They then judged whether they believed they had received active stimulation and rated their confidence in that judgement. The blinded assessor noted when red marks were observed at the electrode sites post-stimulation. RESULTS: tDCS at 2 mA was not effectively blinded. That is, participants correctly judged the stimulation condition greater than would be expected to by chance at both the first session (kappa level of agreement (κ) 0.28, 95% confidence interval (CI) 0.09 to 0.47 p=0.005) and the second session (κ=0.77, 95%CI 0.64 to 0.90), p=<0.001) indicating inadequate participant blinding. Redness at the reference electrode site was noticeable following active stimulation more than sham stimulation (session one, κ=0.512, 95%CI 0.363 to 0.66, p<0.001; session two, κ=0.677, 95%CI 0.534 to 0.82) indicating inadequate assessor blinding. CONCLUSIONS: Our results suggest that blinding in studies using tDCS at intensities of 2 mA is inadequate. Positive results from such studies should be interpreted with caution.
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Cites
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Transcranial direct current stimulation: State of the art 2008
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“Further, there is evidence that incomplete blinding leads to exaggerated effects in clinical studies with subjective outcomes [23], and that placebo effects are larger with physical placebo interventions [22].”
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Brunoni, A. R., Nitsche, M. A., Bolognini, N., Bikson, M., Wagner, T., Merabet, L., Edwards, D. J., Valero-Cabre, A., Rotenberg, A., Pascual-Leone, A., et al. (2012) · Brain stimulation · doi:10.1016/j.brs.2011.03.002 · Cited by 1,445
Publication bias in clinical trials due to statistical significance or direction of trial results
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Placebo interventions for all clinical conditions
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Cited by
A technical guide to tDCS, and related non-invasive brain stimulation tools
Woods, A. J., Antal, A., Bikson, M., Boggio, P. S., Brunoni, A. R., Celnik, P., Cohen, L. G., Fregni, F., Herrmann, C. S., Kappenman, E. S., et al. (2016) · Clinical Neurophysiology · doi:10.1016/j.clinph.2015.11.012 · Cited by 1,439
Kuo, M.-F., Paulus, W., & Nitsche, M. A. (2014) · NeuroImage · doi:10.1016/j.neuroimage.2013.05.117 · Cited by 415
Horvath, J. C., Carter, O., & Forte, J. D. (2014) · Frontiers in Systems Neuroscience · doi:10.3389/fnsys.2014.00002 · Cited by 414
Transcranial direct current stimulation in psychiatric disorders
Tortella, G. (2015) · World Journal of Psychiatry · doi:10.5498/wjp.v5.i1.88 · Cited by 154
Moseley, P., Fernyhough, C., & Ellison, A. (2013) · Neuroscience & Biobehavioral Reviews · doi:10.1016/j.neubiorev.2013.10.001 · Cited by 113
Metadata
- Authors
- O’Connell, N. E., Cossar, J., Marston, L., Wand, B. M., Bunce, D., Moseley, G. L., & De Souza, L. H.
- Venue
- PLoS ONE
- Publisher
- Public Library of Science (PLoS)
- Published
- 2012-10-17
- Volume
- 7
- Issue
- 10
- Pages
- e47514
- ISSN
- 1932-6203 (ISSN-L)
- OpenAlex
- W2163144811
- Cited by
- 264
- References
- 36
- FWCI
- 9.15
- Type
- journal article
- Language
- en
- Open access
- gold
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- O’Connell, N. E., Cossar, J., Marston, L., Wand, B. M., Bunce, D., Moseley, G. L., & De Souza, L. H. (2012). Rethinking Clinical Trials of Transcranial Direct Current Stimulation: Participant and Assessor Blinding Is Inadequate at Intensities of 2mA. PLoS ONE. https://doi.org/10.1371/journal.pone.0047514
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