Does Low-Dose Aspirin Increase Risk for Intracranial Bleeding?

In primary care populations, the extent to which low-dose aspirin heightens risk for intracranial bleeding is unclear. In this study, researchers estimated this risk in a large established U.K. database that is demographically representative of the country's population. About 200,000 new users (age range, 40−80) of low-dose aspirin were matched by age, sex, and comorbidities with about 200,000 nonusers, and a nested case-control study was performed. Contamination by unrecorded over-the-counter aspirin use is minimal in this database, according to the authors' previous research.

During median follow-up of 5.4 years, 1611 cases of intracranial bleeding occurred (46% intracerebral hemorrhage, 30% subdural hematoma, and 24% subarachnoid hemorrha…