Can we improve the statistical analysis of stroke trials? Statistical reanalysis of functional outcomes in stroke trials

Optimising Analysis of Stroke Trials Collaboration, OAST (2007) Can we improve the statistical analysis of stroke trials? Statistical reanalysis of functional outcomes in stroke trials. Stroke, 38 . pp. 1911-1915. ISSN 0039-2499

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
316Kb

Official URL: http://stroke.ahajournals.org/cgi/reprint/38/6/1911

Abstract

Background and Purpose—Most large acute stroke trials have been neutral. Functional outcome is usually analyzed using a yes or no answer, eg, death or dependency versus independence. We assessed which statistical approaches are most efficient in analyzing 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 analyzed using a variety of approaches which compare 2 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 (2; ANOVA, P0.001). The findings were consistent across different types and sizes of trial and for the different measures of functional outcome. Conclusions—When analyzing 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, test, and robust ranks test.

Item Type:Article
Schools/Departments:University of Nottingham UK Campus > Faculty of Medicine and Health Sciences > School of Medicine > Division of Clinical Neuroscience
ID Code:1059
Deposited By:Sayers, Hazel
Deposited On:30 Jan 2009 16:24
Last Modified:15 Aug 2013 08:32

Repository Staff Only: item control page