During my consultation with a new patient I will ask about medication and they will tell me about all the prescription meds they take. Interestingly they tend to forget daily aspirin, and when I ask, I have heard multiple times “of course I take daily baby aspirin” as if it were proven to be effective. Most of you probably remember from a recent newsletter that three studies published in the 9-16-18 New England Journal of Medicine found that aspirin did not lower cardiovascular risk but increased risk of bleeding.
Another study has been published in the 1-22-19 Journal of the American Medical Association on the use of aspirin in healthy people to reduce the risk of cardiovascular disease. Here is the conclusion they published: The use of aspirin in individuals without cardiovascular disease was associated with a lower risk of cardiovascular events and an increased risk of major bleeding. This information may inform discussions with patients about aspirin for primary prevention of cardiovascular events and bleeding.
Lets look a little deeper at the results rather than the conclusion we have been given. They took the numbers from several studies already done for this study. There were 164 225 participants with 1,050,511 participant-years of follow-up. If you followed one person for 10 years you would have 10 participant years. The numbers of reduced cardiovascular events are: 57.1 per 10 000 participant-years with aspirin and 61.4 per 10 000 participant-years with no aspirin.
This means that the risk of a cardiovascular event was reduced from 61.4 to 57.1 per 10,000 participant years.
What about the increased risk of bleeding? The risk of bleeding from taking a baby aspirin daily was 23.1 per 10 000 participant-years with aspirin and 16.4 per 10 000 participant-years with no aspirin.
It has been said that you can use statistics to say anything you want, but what these numbers say is that you have about a 50% higher risk of bleeding to death than preventing a cardiovascular event if you take daily baby aspirin. Isn’t it funny that is not mentioned in the conclusion?