Electrocardiogram interpretation in general practice

background Common diagnostic test in GP

(cardiac complaints) Difficulties of interpreting ECG: GP

and residents > cardiologists More correct interpretation of ECG

achieved by using interpretative ECG recorders

Objectives To know the sensitivity and the

specificity of ECG interpretation by both GPs and interpretative recorders.

Methods Setting: Ebeltoft, Denmark Population: 902 ECGs (randomised aged 31-

51 population) Cross-sectional study Gold standard: cardiologist ‘s interpretation GPs not blinded to:

– Results of interpretive ECG recorder– History and other clinical data

Cardiologist not blinded to:– Results of interpretive ECG recorder

Methods 10 % of random sample of ECG viewed by

an other cardiologist, Statistic tool: SPSS, McNemar’s test: sensitivity and specificity of

diagnoses made by both GPs and ECG recorders,

Kappa: interobserver agreement on the diagnoses made by two cardiologists.

Results 902 of 905 ECGs 429 men (47.6%), 473 women (52.4%) Median age: 41 years (men and

women) Kappa = 0.856 (95% CI: 0.742-0.970)

Results abnormal ECGM+

(cardio)

M-

cardio

M+

(GP)

182

M-

(GP)

720

96 806 902

Results abnormal ECG If the sensitivity = 69.8%

Results abnormal ECGM+

(cardio)

M-

(cardio)

M+

(MG)

67 115 182

M-

(MG)

29 691 720

96 806 902

Results abnormal ECGGP ECG recorder

Sensibility

(p<0.001)

69.8% 84.4%

Spécificity (p<0.001)

85.7% 75.6%

PPV 36.8% 29.1%

PNV 96% 97.6%

Results ischaemia or myocardial infarction

GP ECG recorder

Sensibility

(p<0.001)

22.6% 64.5%

Specificity

(p<0.001)

94.1% 84.5%

PPV 12.1% 12.9%

PNV 97.2% 98.5%

Results any bundle branch

Sensitivity and specificity: no significant difference

Conclusions Higher sensitivity with ECG recorder than

with GPs false-negative low for recoder stay very low in general

the GP have to attempt to achieve a better sensitivity (abnormal ECG reading by the recorder to a specialist, a training,…)

Higher specificity with GPs than with ECG recorder

Conclusions PPV: low PNV: high Low prevalence of abnormal ECG in

this population

Positive point GPs never knew that their ECG

interpretation skills will be evaluated real skills of the GPs

Negative points Not blinding of the GPs Not blinding of the cardiologist The same training in Belgium and in

Denmark? One ECG recorder; and the other

ones?