Skip to main content

Research Repository

Advanced Search

Outcome Assessment by Central Adjudicators Versus Site Investigators in Stroke Trials: A Systematic Review and Meta-Analysis


Peter J. Godolphin

Stroke Association Professor of Stroke Medicine

Ale Algra

Eivind Berge

Martin M. Brown

John Chalmers

Lelia Duley

Misha Eliasziw

John Gregson

Jacoba P. Greving

Graeme J. Hankey

Naohisa Hosomi

S. Claiborne Johnston

Emily Patsko

Annamarei Ranta

Per Morten Sandset


Christian Weimar

Director, nottingham Clinical Trials Unit

S.C. Knipp

R.P. Giugliano

L.H. Bonati

Y. Nagai

M. Matsumoto

H.J.M. Barnett

A.J. Fox

M. Farrant

J.D. Easton

J.J. Elm

B. Neal

H. Arima


P. Amarenco

S. Evans

Professor of Stroke Medicine

J.W. Eikelboom

C. Chen

on behalf of the Adjudicating Outcomes in Stroke Trials Collaboration*


© 2019 American Heart Association, Inc. Background and Purpose-In randomized stroke trials, central adjudication of a trial's primary outcome is regularly implemented. However, recent evidence questions the importance of central adjudication in randomized trials. The aim of this review was to compare outcomes assessed by central adjudicators with outcomes assessed by site investigators. Methods-We included randomized stroke trials where the primary outcome had undergone an assessment by site investigators and central adjudicators. We searched MEDLINE, EMBASE, CENTRAL (Cochrane Central Register of Controlled Trials), Web of Science, PsycINFO, and Google Scholar for eligible studies. We extracted information about the adjudication process as well as the treatment effect for the primary outcome, assessed both by central adjudicators and by site investigators. We calculated the ratio of these treatment effects so that a ratio of these treatment effects >1 indicated that central adjudication resulted in a more beneficial treatment effect than assessment by the site investigator. A random-effects meta-analysis model was fitted to estimate a pooled effect. Results-Fifteen trials, comprising 69 560 participants, were included. The primary outcomes included were stroke (8/15, 53%), a composite event including stroke (6/15, 40%) and functional outcome after stroke measured on the modified Rankin Scale (1/15, 7%). The majority of site investigators were blind to treatment allocation (9/15, 60%). On average, there was no difference in treatment effect estimates based on data from central adjudicators and site investigators (pooled ratio of these treatment effects=1.02; 95% CI, [0.95-1.09]). Conclusions-We found no evidence that central adjudication of the primary outcome in stroke trials had any impact on trial conclusions. This suggests that potential advantages of central adjudication may not outweigh cost and time disadvantages in stroke studies if the primary purpose of adjudication is to ensure validity of trial findings.


Godolphin, P. J., Bath, P. M., Algra, A., Berge, E., Brown, M. M., Chalmers, J., …on behalf of the Adjudicating Outcomes in Stroke Trials Collaboration*. (2019). Outcome Assessment by Central Adjudicators Versus Site Investigators in Stroke Trials: A Systematic Review and Meta-Analysis. Stroke, 50(8), 2187-2196.

Journal Article Type Article
Acceptance Date Apr 25, 2019
Online Publication Date Jun 10, 2019
Publication Date 2019-08
Deposit Date Jun 13, 2019
Publicly Available Date Jun 17, 2019
Journal Stroke
Print ISSN 0039-2499
Electronic ISSN 1524-4628
Publisher American Heart Association
Peer Reviewed Peer Reviewed
Volume 50
Issue 8
Pages 2187-2196
Keywords Advanced and Specialised Nursing; Clinical Neurology; Cardiology and Cardiovascular Medicine
Public URL
Publisher URL


You might also like

Downloadable Citations