Abstract MP07: Rising Incidence and Prevalence of Atrial Fibrillation from 2004 to 2013: A Community-Based Study Using Electronic Medical Records

Abstract

Introduction: Atrial fibrillation (AF) is the most common cardiac arrhythmia observed in clinical practice and is associated with an elevated risk of stroke and mortality. Evaluating community-level temporal trends in AF incidence and prevalence serve to describe the evolving public health and clinical burden of AF, however recent studies describing AF trends in community-based settings have been inconsistent, with no recent data evaluating trends among individuals under 65 years of age. Accordingly, this study sought to describe community-level trends in AF incidence and prevalence from 2004 to 2013 using the electronic medical records (EMR) of a single, large health care system. Methods: This study includes 329,634 patients receiving primary care and other health care services through the Geisinger Health System (Geisinger) over at least a two-year period. Geisinger consists of over 40 outpatient and seven inpatient facilities spread throughout central and northeastern Pennsylvania. Geisinger’s extensive EMR data repository contains information on demographics, vital signs, social history, diagnoses, medical history, problem lists, medications, procedures, laboratory results, and billing information from all Geisinger encounters since 2001. Incident and prevalent AF were identified by ICD-9 codes observed within any EMR domain. For incident AF, cases had no AF ICD-9 code in the EMR for at least two years prior to the diagnosis. Incidence and prevalence rates were age- and sex-adjusted to the 2010 US census and reported per 1000 person-years (persons). Stratified rates are reported across age groups (<45, 45-54, ¼, >85) and sex. Results: Age- and sex-adjusted AF incidence rates remained relatively stable from 2004 to 2008, but increased sharply thereafter. Incidence rates were 5.0, 5.2, and 8.4 cases per 1000 person-years in 2004, 2008, and 2013, respectively. The overall annual increase was 5.5% per year (95% CI: 4.8, 6.3%). Incidence rates increased significantly in all age and gender groups, with the largest relative increase observed among patients <45 years of age (annual increase in males: 10.8%, females: 11.6%). Prevalence rates increased consistently throughout the entire 10-year period from 23.5 to 39.2 AF cases per 1000 persons from 2004 to 2013 (6.0% annual increase; 95% CI: 5.7, 6.4%). Conclusions: AF incidence and prevalence have been increasing in the community over the last 10 years. Increases were observed in all age and gender groups, with notable increases in the very young. Prevailing trends may be attributable to increased application of AF diagnostics in an aging population and/or an increased clinical recognition of AF due to the recent availability of novel oral anticoagulants for stroke prevention. A mature EMR system functioning within a large health care system can be a powerful tool for performing epidemiologic studies and disease surveillance.