The study found an aspirin a day (100mg) did not prolong life free of disability, or significantly reduce the risk of a first heart attack or stroke among participants - with little difference between the placebo and aspirin groups.
Principal investigator Professor John McNeil, head of Monash University’s Department of Epidemiology and Preventive Medicine, said the trial would result in a rethinking of global guidelines relating to the use of aspirin to prevent common conditions associated with ageing.
“Despite the fact that aspirin has been around for more than 100 years, we have not known whether healthy older people should take it as a preventive measure to keep them healthy for longer,” said Professor McNeil.
“Aspirin is the most widely used of all preventive drugs and an answer to this question is long overdue.
“ASPREE has provided this answer.
“These findings will help inform prescribing doctors who have long been uncertain about whether to recommend aspirin to healthy patients who do not have a clear medical reason for doing so.”
The study also showed an increase in the number of cases of serious bleeding among the aspirin takers (3.8%) compared to the placebo group (2.8%).
Bleeding is a well known side effect of aspirin, and is more common in older people.
“It means millions of healthy older people around the world who are taking low dose aspirin without a medical reason, may be doing so unnecessarily, because the study showed no overall benefit to offset the risk of bleeding,” said Professor McNeil.
He cautioned that the results do not apply to those with existing conditions such as a previous heart attack, angina or stroke, where aspirin is recommended as a valuable preventive drug.
He advised all patients to follow the advice of their doctor about their daily use of aspirin.
A small increase in deaths observed in the aspirin group, primarily from cancer, required further investigation as researchers could not rule out that it may be a chance finding. Other large aspirin studies have suggested that aspirin may prevent cancer over the longer term.
Professor McNeil said while aspirin remains a relatively safe medication more research was needed to investigate the longer-term benefits and risks of its daily use.
The researchers are continuing to follow the health of the participants to determine whether beneficial effects of aspirin, such as cancer prevention, emerge sometime after taking the drug.
NOTE: ASPREE’s findings relate ONLY to healthy older people, aged ≥70 years, and do not apply to those taking aspirin on medical advice, for example those who have had a heart attack or stroke.