From the Clinical Pharmacology Department, Hôpital Neuro-Cardiologique, Lyon, France.
In this issue of THE JOURNAL, He and colleagues1 present the
results of a meta-analysis on the risk of hemorrhagic stroke in
patients treated with aspirin at the regimens currently prescribed for
the prevention of carotid, coronary, or peripheral artery thrombotic
occlusion. This review of a subset of 16 randomized controlled trials
of aspirin for the prevention of cerebrovascular accidents, involving
more than 55,000 patients,
confirms that aspirin, even at the average dosage of 273 mg/d (range,
75-1500 mg/d), increases the risk of cerebral bleeding.
Even though the main finding of this study is
not new, important lessons can be drawn from this work. First, He et
al1 provide a quantitative estimate of the excess risk due
to aspirin instead of the vague notion that the risk is increased. This
is another example of a useful application of the meta-analytic
approach for evaluation of adverse events, ie, to assess the unbiased
excess hazards over their natural occurrence when no single trial can
sort out excess risk because the trial is sized for showing an
efficacy.2 Furthermore, this estimate is obtained from the
same patients as those in whom the benefit is measured, thus giving
more relevance to the comparison of benefit and risk.
Boissel J. Individualizing Aspirin Therapy for Prevention of Cardiovascular Events. JAMA. 1998;280(22):1949–1950. doi:10.1001/jama.280.22.1949