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Updated: Jul 15, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Pooled historical MRI data as a basis for research in multiple sclerosis--a statistical evaluation
S Schach1, M Scholz, J S Wolinsky
1Department of Statistics, Dortmund University, D-44221 Dortmund, Germany.
Abstract:
Pooled data from placebo groups of different trials can serve as historical control for ongoing or future therapeutic studies and as a reference for power calculations. In order to assess their usefulness for this purpose, we investigated the degree of heterogeneity of placebo arm data from 14 controlled studies included in the database of the Sylvia Lawry Centre for Multiple Sclerosis Research. Since different criteria for the inclusion/exclusion of patients were used in these studies, an attempt was made to adjust the distribution of magnetic resonance imaging (MRI) measures for the differences in the study populations. The analyses showed that, even after adjustment, significant differences remained. This heterogeneity does not reduce the usefulness of the database for statistical analysis of inter-relationships between variables, provided that it is explicitly taken into account as a stratification factor. However, care must be taken when trying to compare the results of a newly treated group with the patients of this pool. Heterogeneity in some MRI variables was greatly reduced when only studies from the same image analysis centre were compared.
Insights
Pooled placebo data can serve as historical controls in therapeutic studies. However, significant heterogeneity exists in magnetic resonance imaging (MRI) measures, even after adjustments, requiring careful statistical consideration.
Area of Science:
- Neuroimaging
- Clinical Trials
- Biostatistics
Background:
- Pooled placebo data are valuable for historical controls and power calculations in therapeutic studies.
- Investigating heterogeneity in placebo arm data is crucial for assessing database utility.
- The Sylvia Lawry Centre for Multiple Sclerosis Research maintains a database of controlled studies.
Purpose of the Study:
- To assess the usefulness of pooled placebo arm data from multiple sclerosis (MS) trials as historical controls.
- To investigate the degree of heterogeneity in magnetic resonance imaging (MRI) measures within the pooled placebo data.
- To determine if adjustments for population differences can mitigate heterogeneity.
Main Methods:
- Analysis of pooled placebo arm data from 14 controlled studies.
- Adjustment of magnetic resonance imaging (MRI) measures for differences in study populations.
- Stratification analysis to account for heterogeneity.
Main Results:
- Significant heterogeneity was observed in MRI measures across pooled placebo groups, even after population adjustments.
- Heterogeneity was substantially reduced when comparing studies from the same image analysis center.
- The pooled database remains useful for analyzing inter-variable relationships when heterogeneity is explicitly managed.
Conclusions:
- Pooled placebo data offer utility for statistical analyses but require careful handling due to inherent heterogeneity.
- Explicitly accounting for heterogeneity as a stratification factor is essential for valid comparisons.
- Comparing new treatment groups with pooled data necessitates caution due to potential variations in MRI measures.
