Thousands of elderly patients who took part in the landmark ASPREE trial of aspirin for primary prevention will continue to be monitored for a further five years in an observational study.

Researchers behind the Australian-led ASPREE-XT (Aspirin in Reducing Events in the Elderly – Extension) study will examine the health impacts of prolonged aspirin use on cancer, stroke, dementia and other aspects of ageing such as frailty.

The findings from the original trial, published in the New England Journal of Medicine last year, revealed that low-dose aspirin for primary prevention of cardiovascular disease in healthy elderly patients was likely to do more harm than good.

No difference was found in the disability-free survival among those randomised to take 100mg aspirin a day and those on placebo but there was a 38% increased risk of upper gastrointestinal and intracranial bleeds in the active arm.