The study also has limitations worth noting. Migraine classification was based on participants’ recall of physician diagnoses, meaning that some people with migraine may have been misclassified as not having it, potentially underestimating any true association. The age at which participants were diagnosed with migraine was not captured, so researchers could not distinguish between a recent diagnosis and a long history of the condition. And while the study adjusted for a wide range of stroke risk factors, other variables (such as migraine frequency, alcohol use, or hormone replacement therapy) were not accounted for.
