Table 3.

Night-time progression of QTc: mixed, linear regression analysis.

Dependent variable: QTc, ms	Coefficient	SE	95% CI	P
490 m (ref)
2,048 m placebo vs. 490 m	4.7	0.1	4.5 to 4.9	<0.001
2,048 m NOT vs. 490 m	1.8	0.1	1.6 to 2.0	<0.001
Night-time
First 10 min (ref)
11–70 min	3.6	0.3	3.0 to 4.2	<0.001
71–130 min	4.0	0.3	3.4 to 4.6	<0.001
131–190 min	3.3	0.3	2.6 to 3.9	<0.001
191–250 min	3.2	0.3	2.6 to 3.8	<0.001
251–310 min	2.8	0.3	2.2 to 3.4	<0.001
311–370 min	0.9	0.3	0.3 to 1.5	0.003
371–430 min	0.1	0.3	−0.5 to 0.7	0.739
431–480 min	−1.0	0.3	−1.6 to −0.4	0.002
Age, years	0.9	1.4	−1.8 to 3.6	0.504
Sex, male vs. female	−17.2	15.5	−47.6 to 13.2	0.267
FEV1 %pred. at 490 m	−0.3	0.6	−1.5 to 0.9	0.664
Intercept	374.4	110.3	158.2 to 590.5	0.001

The dependent variable QTc was averaged over consecutive 1-min intervals throughout the nights, and a total of 31,589 1-min intervals were included in this mixed, linear regression analysis.

FEV₁, forced expiratory volume in the first second of expiration.