Australia's largest clinical trial has concluded that taking a daily dose of aspirin does not reduce the chance of death, disability or cardiovascular disease, the results of a five-year study revealed on Monday.

Led by researchers at Monash University and involving more than 19,000 participants, the study known as Aspirin in Reducing Events in the Elderly (ASPREE), did reveal a slightly increased risk of major bleeding problems, reports Xinhua news agency.

Head of Monash University's Department of Epidemiology and Preventive Medicine, John McNeil said that the trial was long overdue and he hopes that the results will help inform prescribing doctors who have long been uncertain whether to recommend the drug to otherwise healthy patients.

"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," McNeil said.

"Aspirin is the most widely used of all preventive drugs and an answer to this question is long overdue -- ASPREE has provided this answer."

Aside from the risk of major bleeding problems which rose from 2.8 to 3.8 per cent, no other significant differences were observed between the placebo group and those taking the aspirin.

Researchers have noted that the results only apply to those over 70 years of age who are otherwise healthy and not to those with existing conditions such as a previous heart attack, angina or stroke, where aspirin is recommended as a valuable preventive drug.

McNeil said aspirin remains a relatively safe medication but more research was needed to investigate the longer-term benefits and risks of its daily use.