The effect of different combinations of vascular, dependency and cognitive endpoints on the sample size required to detect a treatment effect in trials of treatments to improve outcome after lacunar and non-lacunar ischaemic stroke

Stephen DJ Makin, Fergus N Doubal, Terence J Quinn, Philip MW Bath, Martin S Dennis, Joanna M Wardlaw (Corresponding Author)

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Background: Endpoints that are commonly used in trials of moderate/severe stroke may be less frequent in patients with minor, non-disabling stroke thus inflating sample sizes. We tested whether trial efficiency might be improved with composite endpoints. Methods: We prospectively recruited patients with lacunar and minor non-lacunar ischaemic stroke (NIHSS /= 3 and 29/158 (19%) had ACE-R /= 3 alone would require n > 5000 participants, recurrent vascular events alone n = 9908 participants, and a composite of any recurrent vascular event, ACE-R /= 2 (present in 56% of patients) n = 2224 patients. However, including cognition increased missing data. Results were similar for lacunar and non-lacunar minor ischaemic stroke. Conclusions: Composite outcomes including vascular events, dependency, and cognition reduce sample size and increase efficiency, feasibility, and relevance to patients of RCTs in minor ischaemic stroke. Efficiency might be improved further with more practical cognitive test strategies.
Original languageEnglish
Pages (from-to)66-73
Number of pages8
JournalEuropean Stroke Journal
Issue number1
Early online date5 Sep 2017
Publication statusPublished - 2018



  • Stroke cognition dependency
  • lacunar outcome
  • power calculation
  • randomised trial sample size

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