Table 4.

Reclassification table showing predicted probabilities for SCD odds from adjusted logistic regression model without and with ECG variables.

Model without ECG variables*	Model with ECG variables
Cases	<0.50†	0.50 – 0.69†	≥ 0.70†	Total
<0.50	79	43	3	125 (39%)
0.50 – 0.69	29	61	54	144 (45%)
>=0.70	0	10	38	48 (15%)
Total	108 (34%)	114 (36%)	95 (30%)	317
Controls	<0.50	0.50 – 0.69	>= 0.70	Total
<0.50	175	21	2	198 (62%)
0.50 – 0.69	46	47	14	107 (34%)
>=0.70	0	5	7	12 (4%)
Total	221 (70%)	73 (23%)	23 (7%)	317

Net reclassification improvement = 22.7%, z = 4.811, p <0.0001

^*Logistic model included the following terms: EF ≤35% vs. >35%, age, sex, diabetes, and hypertension. In the model with ECG markers, each marker (heart rate, JTc, and QRS) was entered separately as a dichotomous variable (≥75^th vs. <75^th percentile).

^†Predicted probabilities from the logistic regression model. Note that when the predicted probability is 0.5, then the two outcomes (SCD or no SCD) are equally likely.

Green colors indicate an improvement in prediction of SCD odds with addition of ECG markers (movement from lower to higher predicted probability for cases, and from higher to lower predicted probability for controls); red colors indicate worsening prediction (movement from higher to lower predicted probability for cases, and from lower to higher predicted probability for controls).