title: Triage tests for identifying atrial fibrillation in primary care: a diagnostic accuracy study comparing single-lead ECG and modified BP monitors.
abstract: OBJECTIVE
  New electronic devices offer an opportunity within routine primary care settings for improving the detection of atrial fibrillation (AF), which is a common cardiac arrhythmia and a modifiable risk factor for stroke. We aimed to assess the performance of a modified blood pressure (BP) monitor and two single-lead ECG devices, as diagnostic triage tests for the detection of AF.
  
  
  METHODS
  6 General Practices in the UK.
  
  
  METHODS
  1000 ambulatory patients aged 75 years and over.
  
  
  METHODS
  Comparative diagnostic accuracy of modified BP monitor and single-lead ECG devices, compared to reference standard of 12-lead ECG, independently interpreted by cardiologists.
  
  
  RESULTS
  A total of 79 participants (7.9%) had AF diagnosed by 12-lead ECG. All three devices had a high sensitivity (93.9-98.7%) and are useful for ruling out AF. WatchBP is a better triage test than Omron autoanalysis because it is more specific-89.7% (95% CI 87.5% to 91.6%) compared to 78.3% (95% CI 73.0% to 82.9%), respectively. This would translate into a lower follow-on ECG rate of 17% to rule in/rule out AF compared to 29.7% with the Omron text message in the study population. The overall specificity of single-lead ECGs analysed by a cardiologist was 94.6% for Omron and 90.1% for Merlin.
  
  
  CONCLUSIONS
  WatchBP performs better as a triage test for identifying AF in primary care than the single-lead ECG monitors as it does not require expertise for interpretation and its diagnostic performance is comparable to single-lead ECG analysis by cardiologists. It could be used opportunistically to screen elderly patients for undiagnosed AF at regular intervals and/or during BP measurement.
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Kearley
authors.forename: Mary
authors.initials: M
authors.lastname: Selwood
authors.forename: Ann
authors.initials: A
authors.lastname: Van den Bruel
authors.forename: Matthew
authors.initials: M
authors.lastname: Thompson
authors.forename: David
authors.initials: D
authors.lastname: Mant
authors.forename: Fd Richard
authors.initials: FR
authors.lastname: Hobbs
authors.forename: David
authors.initials: D
authors.lastname: Fitzmaurice
authors.forename: Carl
authors.initials: C
authors.lastname: Heneghan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis*; D001795:Blood Pressure Determination / Q000295:instrumentation; D004562:Electrocardiography / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D011320:Primary Health Care; D015203:Reproducibility of Results; D014218:Triage
keywords: Primary Care; Stroke Medicine