10.5061/DRYAD.609BP7M
Ganesh, Aravind
University of Oxford
Luengo-Fernandez, Ramon
University of Oxford
Wharton, Rose M.
University of Oxford
Rothwell, Peter M.
University of Oxford
Data from: Ordinal vs dichotomous analyses of modified Rankin Scale and
5-year outcome and cost of stroke
Dryad
dataset
2019
[ 17 ] Prognosis
All Cerebrovascular disease/Stroke
Outcome research
[ 112 ] Outcome research
Clinical trials Methodology/study design
Cohort studies
[ 21 ] Clinical trials Methodology/study design
2019-08-09T00:00:00Z
2019-08-09T00:00:00Z
en
https://doi.org/10.1212/WNL.0000000000006554
516304 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Objective – To compare how three common representations (ordinal versus
dichotomized as 0-1/2-6 or 0-2/3-6) of the modified Rankin Scale (mRS) – a
commonly-used trial outcome measure – relate to long-term outcomes, and
quantify trial ineligibility rates based on pre-morbid mRS. Methods – In
consecutive ischaemic stroke patients in a population-based, prospective
cohort study (Oxford Vascular Study; 2002-2014), we related 3-month mRS to
1-year and 5-year disability and death (logistic regressions), and
health/social-care costs (generalized linear model), adjusted for age/sex,
and compared goodness-of-fit values (c-statistic, Mean Absolute Error
[MAE]). We also calculated the proportion of patients in whom pre-morbid
mRS >1 or >2 would result in exclusion from trials using
dichotomous analysis. Results – Among 1,607 patients, the ordinal mRS was
more strongly related to 5-year mortality than both the 0-1/2-6 and
0-2/3-6 dichotomies (all p<0.0001). Results were similar for 5-year
disability, and 5-year care costs were also best captured by the ordinal
model (ΔMAE versus age/sex: -3,059 for ordinal, -2,805 for 0-2/3-6, -1,647
for 0-1/2-6). 244 (17.1%) 3-month survivors had pre-morbid mRS>2
and 434 (30.5%) had mRS>1; both proportions increased with female
sex, socio-economic deprivation, and age (all p<0.0001).
Conclusions – The ordinal form of the 3-month mRS relates better to
long-term outcomes and costs in survivors of ischaemic stroke than either
dichotomy. This finding favours using ordinal approaches in trials
analysing the mRS. Exclusion of patients with higher pre-morbid disability
by use of dichotomous primary outcomes will also result in
unrepresentative samples.
Online Supplement Neurology 14Jul2018 - Clean CopyContains eTables 1-19,
eFigures 1-7