Professor PHILIP BATH philip.bath@nottingham.ac.uk
STROKE ASSOCIATION PROFESSOR OF STROKE MEDICINE
Can we improve the statistical analysis of stroke trials? Statistical re-analysis of functional outcomes in stroke trials
Bath, Philip M.W.; Optimising Analysis of Stroke Trials Collaboration, OAST
Authors
OAST Optimising Analysis of Stroke Trials Collaboration
Abstract
Background: Most large acute stroke trials have been neutral. Functional outcome is usually analysed using a yes or no answer, e.g. death or dependency vs. independence. We assessed which statistical approaches are most efficient in analysing outcomes from stroke trials.
Methods: Individual patient data from acute, rehabilitation and stroke unit trials studying the effects of interventions which alter functional outcome were assessed. Outcomes included modified Rankin Scale, Barthel Index, and ‘3 questions’. Data were analysed using a variety of approaches which compare two treatment groups. The results for each statistical test for each trial were then compared.
Results: Data from 55 datasets were obtained (47 trials, 54,173 patients). The test results differed substantially so that approaches which use the ordered nature of functional outcome data (ordinal logistic regression, t-test, robust ranks test, bootstrapping the difference in mean rank) were more efficient statistically than those which collapse the data into 2 groups (chi square) (ANOVA p<0.001). The findings were consistent across different types and sizes of trial and for the different measures of functional outcome.
Conclusions: When analysing functional outcome from stroke trials, statistical tests which use the original ordered data are more efficient and more likely to yield reliable results. Suitable approaches included ordinal logistic regression, t-test, and robust ranks test.
Citation
Bath, P. M., & Optimising Analysis of Stroke Trials Collaboration, O. (2007). Can we improve the statistical analysis of stroke trials? Statistical re-analysis of functional outcomes in stroke trials. Stroke, 38(6), https://doi.org/10.1161/STROKEAHA.106.474080
Journal Article Type | Article |
---|---|
Acceptance Date | Nov 21, 2006 |
Online Publication Date | Apr 26, 2007 |
Publication Date | Jun 1, 2007 |
Deposit Date | Aug 22, 2008 |
Publicly Available Date | Aug 22, 2008 |
Journal | Stroke |
Print ISSN | 0039-2499 |
Electronic ISSN | 1524-4628 |
Publisher | American Heart Association |
Peer Reviewed | Peer Reviewed |
Volume | 38 |
Issue | 6 |
DOI | https://doi.org/10.1161/STROKEAHA.106.474080 |
Keywords | stroke; randomised controlled trial; statistical analysis |
Public URL | https://nottingham-repository.worktribe.com/output/1016779 |
Publisher URL | http://stroke.ahajournals.org/content/38/6/1911 |
Contract Date | Aug 22, 2008 |
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