Introduction
Atrial fibrillation (AF) is the commonest cardiac rhythm disorder globally, and confers a large healthcare burden from mortality and morbidity from stroke/systemic thromboembolism, heart failure, dementia and hospitalisations(1). Accurate, population-level data that can enable ongoing monitoring of AF epidemiology, quality of care at affordable cost, and complications are needed.
In the US, data on AF prevalence/incidence are typically identified in administrative medical databases using inpatient/outpatient/physician claims with ICD 9/10 codes(2, 3). Nonetheless, identification does not include claims from other healthcare services (e.g., nursing skilled facilities) or procedures peculiar to AF (e.g., catheter ablation). It is also common for fully insured individuals with medical/pharmacy benefits, who are on medications such as anticoagulants and heart rhythm control, not to have medical claims with AF ICD 9/10 codes. Indeed, a Canadian study by Tu et al(4) voiced similar concerns and found that an algorithm relying on a combination of criteria yielded higher prevalence than those simply based on hospital admissions, emergency room visits or office visits. Collectively, the aforementioned issues may underestimate our knowledge of the true AF prevalence and incidence and the associated co-morbidity profiles.
In a systematic review of validated methods for identifying AF using administrative data, Jensen et al(5) found that 10 of 16 studies used only inpatient data. We hypothesized that prevalent/incidence data would vary by type of population studied, and associated comorbidities would vary accordingly. The aim of this study was to examine AF prevalence/incidence and associated comorbidity profiles for a large US adult cohort spanning across a wide age range (< 65 and> 65 years) for both males/females based on both medical/pharmacy claims. The prevalence and incidence were comparatively analyzed for different healthcare parameters (i.e., emergency room visit, hospital admission, office visit, office observation, cardioversion, catheter observation, all medical claims, anticoagulant medication, heart rhythm control medication, both medical and pharmacy claims). Finally, we assessed co-morbidity profiles, AF + co-morbidity counts, and multi-morbidity in AF cohorts.