Table 1

Unadjusted relative risks of prolonged QTc in any single lead of the ECG

	Death from all causes		Cardiac death
QTc	RR (95% CI)†	p Value	RR (95% CI)†	p Value
*p<0.05 is significant.
†Upper third v the rest (see appendix on Heart website for details of cut off values).
CI, confidence interval; RR, relative risk.
I	2.1 (1.3 to 3.6)	0.005*	2.2 (0.93 to 5.2)	0.074
II	2.2 (1.3 to 3.8)	0.002*	2.6 (1.1 to 6.2)	0.028*
III	1.8 (1.1 to 3.2)	0.029*	3.1 (1.3 to 7.4)	0.010*
aVR	1.6 (0.96 to 2.8)	0.072	2.0 (0.83 to 4.6)	0.13
aVL	2.5 (1.4 to 4.4)	0.001*	2.6 (1.1 yo 6.2)	0.037*
aVF	1.7 (0.98 to 2.9)	0.058	1.7 (0.70 to 4.0)	0.25
V1	1.9 (1.1 to 3.3)	0.016*	2.1 (0.89 to 5.1)	0.089
V2	2.3 (1.4 to 3.9)	0.002*	1.8 (0.74 to 4.3)	0.19
V3	2.3 (1.3 to 3.9)	0.003*	2.3 (0.95 to 5.7)	0.066
V4	3.1 (1.8 to 5.2)	<0.001*	2.5 (1.1 to 5.9)	0.037*
V5	2.4 (1.4 to 4.0)	0.001*	2.0 (0.84 to 4.7)	0.12
V6	2.9 (1.7 to 4.9)	<0.001*	3.1 (1.3 to 7.3)	0.011*
Mean QTc	2.2 (1.2 to 3.9)	0.009*	2.5 (0.98 to 6.2)	0.056
QTc max	3.2 (1.9 to 5.4)	<0.001*	4.1 (1.7 to 9.8)	0.002*
QTc dispersion	1.4 (0.79 to 2.3)	0.28	0.74 (0.27 to 2.0)	0.56