TY  - JOUR
T1  - A metaregression analysis of the dose-response effect of aspirin on stroke
AU  - Johnson ES, Lanes SF, Wentworth CE, III, Satterfield MH, Abebe BL, Dicker LW
Y1  - 1999/06/14
N1  - 10.1001/archinte.159.11.1248
JO  - Archives of Internal Medicine
SP  - 1248
EP  - 1253
VL  - 159
IS  - 11
N2  - Background 
    We evaluated whether the risk of stroke depends on aspirin dose in patients with a previous transient ischemic attack or stroke.Methods 
    We conducted a metaregression analysis of stroke by using published randomized, placebo-controlled trials. We analyzed studies of patients who had recently had a transient ischemic attack or stroke (ie, secondary prevention). We abstracted data on the treatment regimen and stroke. To evaluate the dose-response relationship, we conducted a metaregression analysis of study-specific risk ratios by means of weighted linear regression.Results 
    Eleven randomized, placebo-controlled trials contributed a total of 5228 patients randomized to aspirin only and 4401 patients randomized to placebo only. The slope of the dose-response curve was virtually flat across a wide range of aspirin doses from 50 to 1500 mg/d (P =.49 for test of slope≠0). Summarizing across studies, aspirin decreases the risk of stroke by about 15% (risk ratio, 0.85; 95% confidence interval, 0.77-0.94).Conclusions 
    Aspirin reduces the risk of stroke by approximately 15%, and this effect is uniform across aspirin doses from 50 to 1500 mg/d. The lowest effective aspirin dose has not yet been identified, but it could be lower than 50 mg/d.
SN  - 0003-9926
M3  - doi: 10.1001/archinte.159.11.1248
UR  - http://dx.doi.org/10.1001/archinte.159.11.1248
ER  -