Pandemic Disruptions of Atrial Fibrillation Care

Project Summary Atrial fibrillation (AF) is a cardiac arrythmia that affects over 5 million individuals in the US and quintuples the risk of stroke. AF is a critical disease state to measure the effects of the COVID-19 pandemic on non-COVID disease because every aspect of stroke prevention in AF is vulnerable to disruption: 1) Patients with new onset AF may be more likely to remain undiagnosed. 2) Established AF patients may have complications that remain undetected and worsen without treatment. 3) Patients newly diagnosed with AF may be less likely to initiate stroke prevention therapy with oral anticoagulation (OAC). 4) Established OAC users may have increased difficulty adhering to therapy. 5) Patients on warfarin, an OAC agent that requires routine blood tests, may have less frequent monitoring. Our goal is to measure the impact of the COVID-19 pandemic on diagnosis, therapy initiation, therapy adherence, monitoring, and health outcomes for patients with AF. We will determine whether pandemic disruptions of AF care have exacerbated health disparities. We will also assess the role of telemedicine, whose uptake has been catalyzed by the pandemic, in offsetting decreased access to in-person care during crises. We will use 2015-2022 claims data for Medicare fee-for-service beneficiaries and Optum® Integrated claims- electronic health record data for commercially insured and Medicare Advantage beneficiaries. We will construct interrupted time series analyses to measure changes in outcomes after pandemic start and pandemic end. To determine whether the pandemic has exacerbated disparities, we will test whether the degree of change in outcomes differed by age, sex, race/ethnicity, and area-level measures of urbanization, socioeconomic status, deprivation, racial composition, and segregation. In aims 3 and 4, we will use marginal structural models to estimate the association between telehealth visits and outcomes. We will achieve four specific aims: (1) quantify changes in the incidence rate of new AF diagnoses in 2016-2021, including new AF diagnoses manifesting as stroke; (2) determine whether the COVID-19 pandemic was associated with decreased OAC initiation among newly diagnosed AF patients; (3) quantify changes in adherence and monitoring of OAC therapy among established AF patients; (4) quantify changes in the incidence rates of stroke, bleeding, cardiovascular hospitalization, and death among established AF patients. Our quantification of pandemic effects on AF care will have major implications for the provision of chronic disease care during emergencies. Our identification of populations disproportionately affected by the pandemic and our determination of the ability of telemedicine to offset decreased access to in-person care will inform clinical guidance and policies that prevent care avoidance during health emergencies, optimize models for the delivery of chronic disease care during major crises, and protect vulnerable populations.