Exploring threats to generalisability in a large international rehabilitation trial (AVERT).
OBJECTIVE
The purpose of this paper is to examine potential threats to generalisability of the results of a multicentre randomised controlled trial using data from A Very Early Rehabilitation Trial (AVERT).


METHODS
AVERT is a prospective, parallel group, assessor-blinded randomised clinical trial. This paper presents data assessing the generalisability of AVERT.


METHODS
Acute stroke units at 44 hospitals in 8 countries.


METHODS
The first 20,000 patients screened for AVERT, of whom 1158 were recruited and randomised.


METHODS
We use the Proximal Similarity Model, which considers the person, place, and setting and practice, as a framework for considering generalisability. As well as comparing the recruited patients with the target population, we also performed an exploratory analysis of the demographic, clinical, site and process factors associated with recruitment.


RESULTS
The demographics and stroke characteristics of the included patients in the trial were broadly similar to population-based norms, with the exception that AVERT had a greater proportion of men. The most common reason for non-recruitment was late arrival to hospital (ie, >24 h). Overall, being older and female reduced the odds of recruitment to the trial. More women than men were excluded for most of the reasons, including refusal. The odds of exclusion due to early deterioration were particularly high for those with severe stroke (OR=10.4, p<0.001, 95% CI 9.27 to 11.65).


CONCLUSIONS
A model which explores person, place, and setting and practice factors can provide important information about the external validity of a trial, and could be applied to other clinical trials.


BACKGROUND
Australian New Zealand Clinical Trials Registry (ACTRN12606000185561) and Clinicaltrials.gov (NCT01846247).
Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia.
Julie
J
Bernhardt
Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia.
Audrey
A
Raffelt
Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia.
Leonid
L
Churilov
Westmead Clinical School and The George Institute for Global Health, Westmead Hospital C24, Sydney, New South Wales, Australia.
Richard I
RI
Lindley
Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia.
Sally
S
Speare
Royal Perth Hospital, Perth, Western Australia, Australia.
Jacqueline
J
Ancliffe
Physiotherapy Unit, Medical Rehabilitation Services Department, UKM Medical Centre, Kuala Lumpur, Malaysia.
Md Ali
MA
Katijjahbe
Singapore General Hospital, Singapore, Singapore.
Shahul
S
Hameed
School of Health Sciences, Flinders University, Repatriation General Hospital, Daw Park, South Australia, Australia.
Sheila
S
Lennon
Community and Long Term Conditions Directorate, Auckland District Health Board, Auckland City Hospital, Auckland, New Zealand.
Anna
A
McRae
Department of Physiotherapy, Singapore General Hospital, Singapore, Singapore.
Dawn
D
Tan
Royal Melbourne Hospital, Parkville, Victoria, Australia.
Jan
J
Quiney
Department of Physiotherapy, Austin Health, Austin Hospital, Heidelberg, Victoria, Australia.
Hannah C
HC
Williamson
Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia.
Janice
J
Collier
Florey Institute of Neuroscience and Mental Health, and Faculty of Medicine, Nursing and Health Sciences, Monash University, Box Hill Hospital, Box Hill, Victoria, Australia.
Helen M
HM
Dewey
Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.
Geoffrey A
GA
Donnan
Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK.
Peter
P
Langhorne
School of Clinical Sciences at Monash Health, Monash University, Clayton, Victoria, Australia.
Amanda G
AG
Thrift
D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D005260:Female; D006761:Hospitals; D006801:Humans; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D018579:Patient Selection; D011446:Prospective Studies; D012107:Research Design; D012720:Severity of Illness Index; D012846:Singapore; D000071939:Stroke Rehabilitation; D006113:United Kingdom
Generalisability; Proximal Similarity Model; Randomised Control Trial; Rehabilitation