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Epidemiological modelling of routine use of low dose aspirin for the primary prevention of coronary heart disease and stroke in those aged ≥70

BMJ 2005; 330 doi: (Published 02 June 2005) Cite this as: BMJ 2005;330:1306
  1. Mark R Nelson, chair (Mark.Nelson{at},
  2. Danny Liew, senior lecturer2,
  3. Melanie Bertram, technical officer3,
  4. Theo Vos, associate professor4
  1. 1 Discipline of General Practice, School of Medicine, University of Tasmania, Hobart, TAS 7001, Australia
  2. 2 Department of Epidemiology and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC 3004, Australia
  3. 3 World Health Organization, 1211 Geneva 27, Switzerland
  4. 4 School of Population Health, University of Queensland, Herston, QLD 4006, Australia
  1. Correspondence to: M R Nelson
  • Accepted 13 April 2005


Objective To investigate the routine use of low dose aspirin in people aged ≥ 70 without overt cardiovascular disease.

Design Epidemiological modelling in a hypothetical population.

Setting Reference populations of men and women in the year 2000 from the state of Victoria, Australia.

Subjects 10 000 men and 10 000 women aged 70-74 with no cardiovascular disease.

Main outcome measures First ever myocardial infarction or unstable angina, ischaemic or haemorrhagic stroke, and major gastrointestinal haemorrhage. Health adjusted years of life lived.

Results The proportional benefit gained from the use of low dose aspirin by the prevention of myocardial infarctions (−389 in men, −321 in women) and ischaemic stroke (−19 in men and −35 in women) is offset by excess gastrointestinal (499 in men, 572 in women) and intracranial (76 in men, 54 in women) bleeding. The results in health adjusted years of life lived (which take into account length and quality of life) are equivocal for aspirin causing net harm or net benefit.

Conclusion Epidemiological modelling suggests that any benefits of low dose aspirin on risk of cardiovascular disease in people aged ≥ 70 are offset by adverse events. These findings are tempered by wide confidence intervals, indicating that the overall outcome could be beneficial or adverse.


  • Contributors MRN conceived the paper. DL, TV, and MB developed the model, and DL and TV did the modelling. MRN, DL, and TV wrote the paper with revision and critical input from MB. MRN is the guarantor.

  • Funding DL is supported by a fellowship from the Royal Australasian College of Physicians

  • Competing interests MRN has received aspirin and placebo tablets for an investigator driven trial and travel support from Bayer, a manufacturer of aspirin.

  • Ethical approval Monash University standing committee on ethics in research involving humans (SCERH).

  • Accepted 13 April 2005
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