title: A Clinical Decision Instrument for 30-Day Death After an Emergency Department Visit for Atrial Fibrillation: The Atrial Fibrillation in the Emergency Room (AFTER) Study.
abstract: OBJECTIVE
  The high volume of patients treated in an emergency department (ED) for atrial fibrillation is predicted to increase significantly in the next few decades. Currently, 11% of these patients die within a year. We sought to derive and validate a complex model and a simplified model that predicts mortality in ED patients with atrial fibrillation.
  
  
  METHODS
  This population-based, retrospective cohort study included 3,510 adult patients with a primary diagnosis of atrial fibrillation who were treated at 24 hospital EDs in Ontario, Canada, between April 2008 and March 2009. The main outcome was 30-day all-cause mortality.
  
  
  RESULTS
  In the derivation cohort (n=2,343; mean age 68.8 years), 2.6% of patients died within 30 days of the ED visit versus 2.7% in the validation cohort (n=1,167; mean age 68.3 years). Variables associated with mortality in the complex model included age, presenting pulse rate and systolic blood pressure, presence of chest pain, 2 laboratory results (positive troponin result and creatinine level greater than 200 μmol [2.26 mg/dL]), 4 comorbidities (smoking, chronic obstructive pulmonary disease, cancer, and dementia), an increased bleeding risk, and a second acute ED diagnosis (in addition to atrial fibrillation). Observed 30-day mortality in the 5 risk strata that were defined by the predicted probability of death were 0.44%, 0.41%, 0.23%, 1.61%, and 10.3%. The c statistics were 0.88 and 0.87 in the derivation and validation cohorts, respectively. The a priori-selected 6-variable model, TrOPs-BAC, included a positive Troponin result, Other acute ED diagnosis, Pulmonary disease (chronic obstructive pulmonary disease), Bleeding risk, Aged 75 years or older, and Congestive heart failure. The c statistic for the simplified model was 0.81 in both the derivation and validation cohorts.
  
  
  CONCLUSIONS
  Using a population-based sample, we derived and validated both a complex and a simplified instrument that predicts mortality after an emergency visit for atrial fibrillation. These may aid clinicians in identifying high-risk patients for hospitalization while safely discharging more patients home.
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Division of Emergency Medicine, the Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. Electronic address: clare.atzema@ices.on.ca.
authors.forename: Clare L
authors.initials: CL
authors.lastname: Atzema
authors.affiliation: Cardiology, the Department of Medicine, University of Toronto, Toronto, Ontario, Canada; St Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Dorian
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Jiming
authors.initials: J
authors.lastname: Fang
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Internal Medicine, the Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Institute for Health Policy, Management and Evaluation at the University of Toronto, Toronto, Ontario, Canada.
authors.forename: Jack V
authors.initials: JV
authors.lastname: Tu
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Cardiology, the Department of Medicine, University of Toronto, Toronto, Ontario, Canada; University Health Network, Toronto, Ontario, Canada; Institute for Health Policy, Management and Evaluation at the University of Toronto, Toronto, Ontario, Canada.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Lee
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Alice S
authors.initials: AS
authors.lastname: Chong
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Institute for Health Policy, Management and Evaluation at the University of Toronto, Toronto, Ontario, Canada.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D001794:Blood Pressure; D002637:Chest Pain / Q000401:mortality; D003661:Decision Support Techniques; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000401:mortality; D006339:Heart Rate; D006801:Humans; D008297:Male; D009864:Ontario / Q000453:epidemiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000401:mortality; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods