Table 2.

Use of electronic devices in the last hour before going to sleep and daytime screen use as risk factors for short sleep duration among girls and boys in the youth@hordaland study (n=9846)†

	<5 h		5–6 h		6–7 h		7–8 h
	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI
Electronic devices used in the last hour before bedtime
PC	2.70***	2.14 to 3.39	2.69***	2.09 to 3.46	2.30***	1.90 to 2.79	1.64***	1.38 to 1.96
Cell phone	1.85***	1.45 to 2.35	1.65***	1.28 to 2.13	1.75***	1.42 to 2.15	1.50***	1.24 to 1.83
MP3-player	1.52***	1.29 to 1.78	1.46***	1.12 to 1.73	1.33***	1.15 to 1.53	1.19*	1.03 to 1.36
iPad or other tablet	1.19*	1.01 to 1.41	1.29**	1.09 to 1.54	1.18*	1.92 to 1.37	1.10	0.95 to 1.28
Console	1.40***	1.19 to 1.64	1.38***	1.17 to 1.64	1.27**	1.09 to 1.47	1.17*	1.01 to 1.35
TV	1.51***	1.29 to 1.77	1.44***	1.22 to 1.71	1.35***	1.17 to 1.56	1.16*	1.01 to 1.33
Daytime screen use
Total screen time (4 h+)	3.64***	3.06 to 4.33	2.66***	2.22 to 3.19	2.07***	1.79 to 2.40	1.29***	1.12 to 1.49
Console games (2 h+)	2.03***	1.53 to 2.69	1.73***	1.28 to 2.35	1.58**	1.21 to 2.06	1.20	0.92 to 1.58
PC games (2 h+)	1.90***	1.51 to 2.38	1.22	0.95 to 1.58	1.39**	1.12 to 1.73	1.06	0.86 to 1.32
Online chat (2 h+)	3.58***	3.03 to 4.24	2.79***	2.33 to 3.33	1.98***	1.70 to 2.30	1.31***	1.13 to 1.51
Email (2 h+)	3.28***	2.07 to 5.16	2.42***	1.48 to 3.95	1.34	0.84 to 2.14	1.14	0.72 to 1.82
Other PC use (2 h+)	2.06***	1.74 to 2.42	2.04***	1.71 to 2.44	1.54***	1.33 to 1.78	1.21**	1.05 to 1.39

*p<0.05; **p<0.01; ***p<0.001.

†Reference: 8–9 h.