Home > DARE Reviews > Systematic review and meta-analysis of...

PubMed Health. A service of the National Library of Medicine, National Institutes of Health.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

Systematic review and meta-analysis of adverse events of low-dose aspirin and clopidogrel in randomized controlled trials

Review published: 2006.

Bibliographic details: McQuaid K R, Laine L.  Systematic review and meta-analysis of adverse events of low-dose aspirin and clopidogrel in randomized controlled trials. American Journal of Medicine 2006; 119(8): 624-638. [PubMed: 16887404]

Abstract

PURPOSE: We performed a systematic review to define the relative and absolute risk of clinically relevant adverse events with the antiplatelet agents, aspirin and clopidogrel.

MATERIALS AND METHODS: Databases were searched for randomized controlled trials of low-dose aspirin (75-325 mg/day) or clopidogrel administered for cardiovascular prophylaxis. Relative risks (RR) were determined by meta-analysis of 22 trials for aspirin versus placebo and from single studies for aspirin versus clopidogrel, aspirin versus aspirin/clopidogrel, and clopidogrel versus aspirin/clopidogrel. Absolute risk increase was calculated by multiplying RR increase by the pooled weighted incidence of the control.

RESULTS: Aspirin increased the risk of major bleeding (RR=1.71; 95% confidence interval [CI], 1.41-2.08), major gastrointestinal (GI) bleeding (RR=2.07; 95% CI, 1.61-2.66), and intracranial bleeding (RR=1.65; 95% CI, 1.06-5.99) versus placebo. No difference between 75-162.5 mg/day and >162.5-325 mg/day aspirin versus placebo was seen. The absolute annual increases attributable to aspirin were major bleeding: 0.13% (95% CI, 0.08-0.20); major GI bleeding: 0.12% (95% CI, 0.07-0.19), intracranial bleeding: 0.03% (95% CI, 0.01-0.08). No study compared clopidogrel with placebo. One study showed increased major GI bleeding (but not non-GI bleeding endpoints) with aspirin versus clopidogrel (RR=1.45; 95% CI, 1.00-2.10). The absolute annual increase was 0.12% (95% CI, 0.00-0.28).

CONCLUSIONS: Low-dose aspirin increases the risk of major bleeding by approximately 70%, but the absolute increase is modest: 769 patients (95% CI, 500-1250) need to be treated with aspirin to cause one additional major bleeding episode annually. Compared with clopidogrel, aspirin increases the risk of GI bleeding but not other bleeding; however, 883 patients (95% CI, 357-infinity) would need to be treated with clopidogrel versus aspirin to prevent one major GI bleeding episode annually at a cost of over 1 million dollars.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 16887404

PubMed Health Blog...

read all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...