This study investigates the temporal trends in the association between female sex and ischemic stroke (IS) risk in patients with atrial fibrillation (AF) in Finland from 2007 to 2018. The Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) cohort, covering all patients with incident AF, was analyzed to explore these trends. Key findings include: - **Key Question**: Has the IS risk associated with female sex in AF changed over time? - **Key Finding**: In patients with AF, female sex was independently associated with a 20–30% higher IS rate in 2007–2008, but this association attenuated and became non-significant by the end of the observation period in 2017–2018. - **Take Home Message**: Female sex might be omitted as a factor in the estimation of IS risk, affecting the identification of patients with AF needing anticoagulant therapy. The study used a nationwide retrospective cohort design, covering all patients with incident AF in Finland from 2004 to 2018. Follow-up was analyzed in two approaches: with and without oral anticoagulant (OAC) use. The results showed that while crude IS rates decreased over the study period, particularly in women, the association between female sex and IS rate became non-significant by the end of the observation period. This decline was more pronounced in high-risk patients, while in low- and moderate-risk categories, no significant association was observed. The study concludes that the association between female sex and IS rate has decreased over time, suggesting that female sex could be omitted as a factor when estimating expected IS rates and the need for OAC therapy in patients with AF. However, women tend to be under-treated with OACs and sustain more severe IS events, highlighting the need for continued attention to this issue.This study investigates the temporal trends in the association between female sex and ischemic stroke (IS) risk in patients with atrial fibrillation (AF) in Finland from 2007 to 2018. The Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) cohort, covering all patients with incident AF, was analyzed to explore these trends. Key findings include: - **Key Question**: Has the IS risk associated with female sex in AF changed over time? - **Key Finding**: In patients with AF, female sex was independently associated with a 20–30% higher IS rate in 2007–2008, but this association attenuated and became non-significant by the end of the observation period in 2017–2018. - **Take Home Message**: Female sex might be omitted as a factor in the estimation of IS risk, affecting the identification of patients with AF needing anticoagulant therapy. The study used a nationwide retrospective cohort design, covering all patients with incident AF in Finland from 2004 to 2018. Follow-up was analyzed in two approaches: with and without oral anticoagulant (OAC) use. The results showed that while crude IS rates decreased over the study period, particularly in women, the association between female sex and IS rate became non-significant by the end of the observation period. This decline was more pronounced in high-risk patients, while in low- and moderate-risk categories, no significant association was observed. The study concludes that the association between female sex and IS rate has decreased over time, suggesting that female sex could be omitted as a factor when estimating expected IS rates and the need for OAC therapy in patients with AF. However, women tend to be under-treated with OACs and sustain more severe IS events, highlighting the need for continued attention to this issue.