Intended for healthcare professionals


Low dose aspirin and cognitive function in the women's health study cognitive cohort

BMJ 2007; 334 doi: (Published 10 May 2007) Cite this as: BMJ 2007;334:987
  1. Jae Hee Kang, instructor1,
  2. Nancy Cook, associate professor2,
  3. JoAnn Manson, professor2,
  4. Julie E Buring, professor2,
  5. Francine Grodstein, associate professor1
  1. 1Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
  2. 2Department of Medicine, Division of Preventive Medicine, Brigham and Women's Hospital
  1. Correspondence to: J H Kang nhjhk{at}
  • Accepted 21 February 2007


Objective To determine whether low dose aspirin protects women aged 65 or more against cognitive decline.

Design Cohort study within both arms of the women's health study, a randomised, double blind, placebo controlled trial of low dose aspirin for the primary prevention of cardiovascular disease and cancer, 1992-5.

Setting Women's health study, 1998-2004.

Participants 6377 women aged 65 or more.

Interventions Low dose aspirin (100 mg on alternate days) or placebo for a mean of 9.6 years.

Main outcome measures Women had three cognitive assessments at two year intervals by telephone. The battery to assess cognition included five tests measuring general cognition, verbal memory, and category fluency. The primary prespecified outcome was a global score, averaging performance across all tests. The key secondary outcome was a verbal memory score, averaging performance on four measures of verbal memory.

Results At the initial assessment (mean 5.6 years after randomisation) cognitive performance in the aspirin group was similar to that of the placebo group (mean difference in global score −0.01, 95% confidence interval −0.04 to 0.02). Mean decline in the global score from the first to the final cognitive assessment was also similar in the aspirin compared with placebo groups (mean difference 0.01, −0.02 to 0.04). The risk of substantial decline (in the worst 10th centile of decline) was also comparable between the groups (relative risk 0.92, 0.77 to 1.10). Findings were similar for verbal memory; however, a 20% lower risk was observed for decline in category fluency with aspirin (relative risk 0.80, 0.67 to 0.97).

Conclusion Long term use of low dose aspirin does not provide overall benefits for cognition among generally healthy women aged 65 or more.


  • We thank the participants, staff, and investigators of the women's health study.

  • Contributors: All authors conceived and designed the study. JHK and FG carried out the study. JHK and NC analysed the data. JHK drafted the manuscript and is guarantor. All authors critically reviewed the paper and approved the final draft for publication.

  • Funding: The study was supported by grant AG15933 from the National Institute of Aging, HL-43851 from the National Heart, Lung, and Blood Institute, and CA-47988 from the National Cancer Institute. Aspirin and placebo were provided by Bayer HealthCare.

  • Competing interests: None declared.

  • Ethical approval: The trial was approved by the institutional review board of Brigham and Women's Hospital.

  • Accepted 21 February 2007
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