Grant: Project Grant

Atrial fibrillation (AFib) is a common heart rhythm problem that affects over one million Canadians. People with AFib are at much higher risk of stroke, which can cause permanent disability or death. A group of medications called oral anticoagulants can greatly lower this risk - but only if they are taken regularly. This is called medication adherence. Many studies have shown that people who do not take their medication regularly have more strokes and deaths, but it is not clear whether missed doses directly cause these events, or whether other factors, like differences in health, lifestyle, or access to care, are responsible. Without knowing this, we cannot be sure how much improving adherence will actually save lives. Our study will find out how much nonadherence truly causes strokes and deaths, how the timing of missed doses matters, and which patients are harmed the most. In particular, we will find out whether nonadherence negatively affects certain types of people (e.g. by sex and gender, income levels, rural/urban residence, age category, race/ethnicity) more than others. We will use advanced statistical methods to study 20 years of health data from every person in British Columbia diagnosed with AFib, including prescription records, medical visits, and hospital stays. Then we will incorporate our results into an online risk calculator that clinicians and patients can use to better understand their individual risk of strokes and bleeds with each of the medication options. This research will generate the strongest evidence yet on how much improving medication adherence can prevent strokes and save lives in Afib patients. The results will guide healthcare providers, policymakers, and health systems in targeting support where it will have the greatest impact, leading to more effective prevention strategies and better patient outcomes.