A quarter of older adults are still taking a drug that can cause them to experience internal bleeding, a study has found.
Aspirin was once recommended in the US to people over 60 as a way to prevent heart attack or stroke.
But in 2018, medical organizations began to reverse the advice, saying that for those who had not previously suffered from the conditions, any benefits did not outweigh the risks – including bleeding in the gut or brain.
While the study found that aspirin use declined across the age group after the change in recommendation, it also found that 18.5 million seniors were still using it in 2021, the last date available.
Of these, 3.3 million – or almost five percent of the over-60s population – did so without any medical advice.
Aspirin should not be taken by people over 60 to prevent first heart attack or stroke, doctors say
Aspirin is still recommended for people over 60 who have already had a heart attack or stroke, as it can reduce the risk of a heart attack by about 25 percent.
It is an inexpensive drug – costing just nine cents per tablet – and works by thinning the blood, reducing the risk of clots.
This helps reduce the risk of stroke or heart attack because patients are less likely to develop clots that can cause blockages in the brain or heart.
But doctors have warned that the drug also increases the risk of internal bleeding by reducing the ability of factors in the blood to clump together to form clots and stop potentially serious bleeding.
These bleeds usually occur in the stomach or intestines and can be life-threatening as patients can suffer severe blood loss, which can lead to shock, damage to critical tissue or interrupt the supply of nutrients and oxygen to vital parts of the body. In some cases they also occur in the brain.
Doctors say that in rare cases these bleedings can be fatal.
This is evident from the research published this week in the Annals of Internal Medicineresearchers analyzed data from 180,000 patients aged 40 and older who were asked about their aspirin use between 2012 and 2021.
The data was collected from the National Health Interview Survey (NHIS), an annual survey of 35,000 adults about their health habits.
Researchers from Creighton University in Nebraska and Houston Methodist University in Texas analyzed the data to estimate aspirin use among people in their 60s and older.
They found that 18.5 million people without cardiovascular disease took preventative aspirin in 2021, with 3.3 million taking the pills without a recommendation from their doctor.
They noted that limitations of the study included that it was likely that physician-recommended use of aspirin in this age group was also included in the estimates.
The drug is still recommended for people over 60 who have already had a heart attack or stroke, as it can reduce the risk of a second.
Some doctors will also recommend the drug to select individuals who have evidence of significant plaque buildup in their arteries, increasing the risk of clots.
Research has also shown that in people over 60 years of age, the benefit of reducing the risk of a first heart attack or stroke does not outweigh the risk of a stroke.
About seven percent of adults over 60 have had a stroke, or 5 million people.
Separate figures show that 14 percent of people aged 65 to 74 have also had a heart attack, or 4.6 million people.
Doctors in 2018 slowly started to stop recommending the drug to prevent a first heart attack or stroke, after three clinical trials warned of possible risks.
The American College of Cardiology changed its guidelines in 2018 and the American Heart Association changed them in 2019 to suggest that seniors over 70 who have not yet had a heart attack or stroke should not take aspirin.
In 2022, the U.S. Preventive Services Task Force followed suit, saying people over age 60 should not take aspirin to prevent a first heart attack.