Stroke: aspirin decreases recurrent stroke.

Clinical bottom line (level 1a)

  1. Patients who have had a previous stroke or transient ischaemic attack who are given aspirin, are less likely to have another stroke than those given placebo.
  2. Dosage of aspirin does not seem to make a difference, effect essentially the same with dosage range from 50 to 15000 mg/d.
Johnson et al: Archives of Internal Medicine 1999; 159: 1248-1253
Expires January 2003

The study

Systematic review of randomised placebo-controlled secondary prevention trials. of
  • Patients: recent stroke or transient ischaemic attack
  • Intervention: aspirin compared with placebo
  • Outcome: stroke


    • Articles found in ? using MEDLINE, up until April 30 1996 (search terms: none given ) and manual searching of reference lists of reviews.

    Selection criteria: as above
    Appraisal criteria: detailed in text
    Articles excluded if: not stated

    Eleven trials involving 9629 patients were included.

    The evidence

    Outcome Time to outcome CER RR
    (95% CI)    		 NN?
    (% CI)
    stroke- all doses unknown /
    (%)    		 0.85
    (0.77 to 0.94)

    • Dose response of aspirin was compared with the studies as the dose ranged from 50 mg/day to 1500 mg/day. No dose response was found. Risk ratios were given for the separate doses, but there was no combined data when there was more than one trial using a particular dose.

    Citation

    1. Johnson ES, Lanes SF, Wentworth CE, et al: A metaregression analysis of the dose-response effect of aspirin on stroke. Archives of Internal Medicine 1999; 159: 1248-1253
    Contributor: Clare Wotton and Musab Hayatli, January 2000
    Reviewer:

    Clinical Question.
    Patient stroke
    Intervention or Exposure aspirin
    Comparison placebo
    Outcome stroke