Are power calculations useful? A multicentre neuroimaging study

Suckling, J., Henty, J., Ecker, C., Deoni, S. C., Lombardo, M. V., Baron-Cohen, S., Jezzard, P., Barnes, A., Chakrabarti, B. ORCID: https://orcid.org/0000-0002-6649-7895, Ooi, C., Lai, M.-C., Williams, S. C., Murphy, D. G. M. and Bullmore, E. (2014) Are power calculations useful? A multicentre neuroimaging study. Human Brain Mapping, 35 (8). pp. 3569-3577. ISSN 1065-9471 doi: 10.1002/hbm.22465

Abstract/Summary

There are now many reports of imaging experiments with small cohorts of typical participants that precede large-scale, often multicentre studies of psychiatric and neurological disorders. Data from these calibration experiments are sufficient to make estimates of statistical power and predictions of sample size and minimum observable effect sizes. In this technical note, we suggest how previously reported voxel-based power calculations can support decision making in the design, execution and analysis of cross-sectional multicentre imaging studies. The choice of MRI acquisition sequence, distribution of recruitment across acquisition centres, and changes to the registration method applied during data analysis are considered as examples. The consequences of modification are explored in quantitative terms by assessing the impact on sample size for a fixed effect size and detectable effect size for a fixed sample size. The calibration experiment dataset used for illustration was a precursor to the now complete Medical Research Council Autism Imaging Multicentre Study (MRC-AIMS). Validation of the voxel-based power calculations is made by comparing the predicted values from the calibration experiment with those observed in MRC-AIMS. The effect of non-linear mappings during image registration to a standard stereotactic space on the prediction is explored with reference to the amount of local deformation. In summary, power calculations offer a validated, quantitative means of making informed choices on important factors that influence the outcome of studies that consume significant resources.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/36162
Identification Number/DOI	10.1002/hbm.22465
Refereed	Yes
Divisions	Interdisciplinary Research Centres (IDRCs) > Centre for Integrative Neuroscience and Neurodynamics (CINN) Interdisciplinary centres and themes > ASD (Autism Spectrum Disorders) Research Network Life Sciences > School of Psychology and Clinical Language Sciences > Department of Psychology Life Sciences > School of Psychology and Clinical Language Sciences > Neuroscience Life Sciences > School of Psychology and Clinical Language Sciences > Psychopathology and Affective Neuroscience
Publisher	Wiley
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