Table 2

Performance of GP referral decision on ECG and CHART reports compared with by consensus ground truth

MetricECG report
CHART report
CHART compare to ECG
Hypothesis test with 95% CI
Lower conf. %Observed
value %
Upper conf. %Lower conf. %Observed
value %
Upper conf. %
SE%42.0048.5255.0857.6764.1470.24Significant increase
SP%73.6378.5983.0179.4984.0387.91Significant increase
PPV%55.7463.1970.2068.7075.2581.04Significant increase
NPV%61.7866.8571.6470.7175.5780.00Significant increase
K%22.5227.9033.7142.8949.0455.25Significant increase
AUC%66.0270.8075.0274.4479.1383.03Significant increase
LR+1.842.272.863.134.015.30Significant increase
LR−0.700.650.620.450.430.41Significant decrease
PR%29.1733.0937.2032.6936.7340.91Less significant increase
  • Better performance values are shown in bold.

  • Confusion matrices and performance equations available in online supplemental file 1.

  • AUC, area under the curve; CHART, Cardio-HART; GP, general practitioner; K, kappa statistics; LR+, positive Likelihood Ratio; LR−, Negative Likelihood Ratio; NPV, negative predictive value; PPV, positive predictive value; PR, positive rate; SE, sensitivity; SP, specificity.