Table 2. Inter-method variability.

	Pearson correlation		Intra-class coefficient		Bland-Altman
	r (95% CI)	p	ICC (95% CI)	p	Mean difference (ms)	Limits of agreement (ms)
QTalg vs. QTobs1	0.959 (0.949–0.966)	< 0.001	0.956 (0.943–0.966)	< 0.001	3.39	-23.23: 30.01
QTalg vs. QTobs2	0.935 (0.920–0.946)	< 0.001	0.933 (0.917–0.945)	< 0.001	-2.65	-36.09: 30.79
QTalg vs. QTobs3	0.948 (0.936–0.957)	< 0.001	0.947 (0.935–0.957)	< 0.001	-1.88	-31.53: 27.78
QTalg vs. μQTobs	0.962 (0.954–0.969)	< 0.001	0.981 (0.976–0.984)	< 0.001	-0.38	-25.41: 24.65

95% CI = 95% confidence interval, obs = observer(s), r = Pearson’s r, p = p-value, ICC = intra-class coefficient, ms = milliseconds.