This Article  • Full text  • PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citing articles on HighWire  • Contact me when this article is cited  Related Content  • Related articles  • Similar articles in JAMA  Topic Collections  • Evidence-Based Medicine  • Women's Health, Other  • Aging/ Geriatrics  • Cardiovascular Disease/ Myocardial Infarction  • Alert me on articles by topic

	Since this article does not have an abstract, we have provided the first 150 words of the full text and any section headings.

To the Editor: In their sex-specific meta-analysis of aspirin in the primary prevention of cardiovascular disease, Dr Berger and colleagues¹ found results similar to the meta-analysis we performed as part of the primary report of the Women's Health Study.² However, meta-analyses can hide important clinical effects—in this case, the evidence of effect modification by age. In the Women's Health Study, the most consistent benefit of aspirin was observed among women aged 65 years or older, a group who comprised only 10% of the study population yet had almost one third of the total cardiovascular events.

This is relevant to any discussion of number needed to treat (NNT) and number needed to harm (NNH). Berger et al compared these measures between all men and all women and found little difference. However, the data in the Women's Health Study allowed age-specific estimates of the 10-year NNT and NNH for low-dose aspirin compared . . . [Full Text of this Article]

Paul M Ridker, MD
pridker@partners.org

Nancy R. Cook, ScD; Julie E Buring, ScD
Brigham and Women's Hospital
Boston, Mass

RELATED ARTICLES

Use of Aspirin as Primary Prevention of Cardiovascular Events
James E. Dalen
JAMA. 2006;296(4):391.
EXTRACT | FULL TEXT  

Use of Aspirin as Primary Prevention of Cardiovascular Events—Reply
Jeffrey S. Berger and David L. Brown
JAMA. 2006;296(4):391-392.
EXTRACT | FULL TEXT  

Aspirin for the Primary Prevention of Cardiovascular Events in Women and Men: A Sex-Specific Meta-analysis of Randomized Controlled Trials
Jeffrey S. Berger, Maria C. Roncaglioni, Fausto Avanzini, Ierta Pangrazzi, Gianni Tognoni, and David L. Brown
JAMA. 2006;295(3):306-313.
ABSTRACT | FULL TEXT  

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Cost-Effectiveness of Aspirin Treatment in the Primary Prevention of Cardiovascular Disease Events in Subgroups Based on Age, Gender, and Varying Cardiovascular Risk
Greving et al.
Circulation 2008;117:2875-2883.
ABSTRACT | FULL TEXT