Accuracy of diagnosing atrial fibrillation on electrocardiogram by primary care practitioners and interpretative diagnostic software: analysis of data from screening for atrial fibrillation in the elderly (SAFE) trial.
OBJECTIVE
To assess the accuracy of general practitioners, practice nurses, and interpretative software in the use of different types of electrocardiogram to diagnose atrial fibrillation.


METHODS
Prospective comparison with reference standard of assessment of electrocardiograms by two independent specialists.


METHODS
49 general practices in central England.


METHODS
2595 patients aged 65 or over screened for atrial fibrillation as part of the screening for atrial fibrillation in the elderly (SAFE) study; 49 general practitioners and 49 practice nurses.


METHODS
All electrocardiograms were read with the Biolog interpretative software, and a random sample of 12 lead, limb lead, and single lead thoracic placement electrocardiograms were assessed by general practitioners and practice nurses independently of each other and of the Biolog assessment.


METHODS
Sensitivity, specificity, and positive and negative predictive values.


RESULTS
General practitioners detected 79 out of 99 cases of atrial fibrillation on a 12 lead electrocardiogram (sensitivity 80%, 95% confidence interval 71% to 87%) and misinterpreted 114 out of 1355 cases of sinus rhythm as atrial fibrillation (specificity 92%, 90% to 93%). Practice nurses detected a similar proportion of cases of atrial fibrillation (sensitivity 77%, 67% to 85%), but had a lower specificity (85%, 83% to 87%). The interpretative software was significantly more accurate, with a specificity of 99%, but missed 36 of 215 cases of atrial fibrillation (sensitivity 83%). Combining general practitioners' interpretation with the interpretative software led to a sensitivity of 92% and a specificity of 91%. Use of limb lead or single lead thoracic placement electrocardiograms resulted in some loss of specificity.


CONCLUSIONS
Many primary care professionals cannot accurately detect atrial fibrillation on an electrocardiogram, and interpretative software is not sufficiently accurate to circumvent this problem, even when combined with interpretation by a general practitioner. Diagnosis of atrial fibrillation in the community needs to factor in the reading of electrocardiograms by appropriately trained people.
Mant
Jonathan
J
Department of Primary Care and General Practice, University of Birmingham, Birmingham B15 2TT.
Fitzmaurice
David A
DA
Hobbs
F D Richard
FD
Jowett
Sue
S
Murray
Ellen T
ET
Holder
Roger
R
Davies
Michael
M
Lip
Gregory Y H
GY
D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis*; D002983:Clinical Competence / Q000592:standards*; D003936:Diagnosis, Computer-Assisted / Q000592:standards*; D004562:Electrocardiography / Q000592:standards*; D004739:England; D005194:Family Practice / Q000592:standards*; D006801:Humans; D009722:Nurse Practitioners / Q000592:standards*; D011237:Predictive Value of Tests; D011446:Prospective Studies