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Question clinique
Are the effects of aspirin in primary prevention modified by patients' weight?
L’Essentiel
In this large secondary analysis of individual patient data from multiple randomized trials, low-dose aspirin for the primary prevention of cardiovascular events and cancer is less effective in patients who weigh more than 70 kg. The secondary analysis of data in this manner is probably best for generating hypotheses to be further tested, so the results are not quite ready for prime time. These data also should be interpreted in light of brand new trial data from older patients—that study was released at the same time as this POEM. Stay tuned! 1a
Référence
Plan de l'etude: Meta-analysis (randomized controlled trials)
Financement: Foundation
Cadre: Various (meta-analysis)
Sommaire
These authors searched previous systematic reviews and obtained data from a collaboration of researchers who conducted clinical trials of antithrombotic agents. The chosen trials had to include more than 1000 patients, last longer than 90 days, and have authors who were willing to share individual patient data. Although this is not your typical systematic review search strategy it likely identified most of the important studies. The primary purpose of this paper was to address the potential association between aspirin dose and body weight. The authors included 10 trials for primary prevention of cardiovascular events (more than 117,000 patients) and 5 for cancer prevention (more than 73,000 patients). They didn't assess the risk of bias for the included studies, didn't formally assess the potential for publication bias, and didn't adjust for conducting multiple analyses. After slicing and dicing the data, they determined that for preventing cardiovascular outcomes and cancer, the effectiveness of aspirin varied by dose and patient sex and weight. The effectiveness of low-dose aspirin (< 100 mg daily) to prevent cancer or a first cardiac event was diminished in patients who weigh more than 70 kg, and was even less effective in men than women. For patients who weigh less than 70kg the hazard ratio was 0.77 (95% CI 0.68 - 0.87) and for those who weigh 70 kg or more the hazard ratio was 0.95 (0.86 - 1.04). Additionally, among patients who weigh less than 50 kg, low-dose aspirin was associated with an increased risk of death from any cause.
Reviewer
Henry C. Barry, MD, MS
Professor
Michigan State University
East Lansing, MI
Commentaires
Suggest this be used as classic example of “p hacking”
ASA in primary prevention
The evidence for ASA use in primary prevention is so low that this study is likely of no significance
So it's good for Goldilocks, but bad for all the bears.
I anticipate discussing the use of other anti platelet medications for selected patients, e.g. clopidrogrel, when the patient weight would suggest no benefit from ASA.
Good poem
Excellent