Table 1

Use of electronic devices in the last hour before bedtime and daytime screen use as risk factors for sleep onset latency (SOL) of 60 min or more, and sleep deficiency of 2 h or more in the youth@hordaland study (n=9846)†

	SOL (≥60 min)		Sleep deficit (≥2 h)
	OR	95% CI	OR	95% CI
Electronic devices used in the last hour before bedtime
PC	1.52***	1.34 to 1.71	1.53***	1.34 to 1.76
Cell phone	1.48***	1.30 to 1.68	1.35***	1.17 to 1.55
MP3-player	1.36***	1.25 to 1.48	1.21***	1.10 to 1.32
Tablet	1.18***	1.08 to 1.29	1.12*	1.02 to 1.23
Console	1.13***	1.04 to 1.23	1.20***	1.10 to 1.32
TV	1.19***	1.10 to 1.30	1.36***	1.24 to 1.49
Daytime screen use
Total screen time (4 h+)	1.49***	1.36 to 1.64	1.72***	1.56 to 1.89
Console games (2 h+)	1.20*	1.04 to 1.38	1.31***	1.13 to 1.52
PC games (2 h+)	1.19**	1.05 to 1.34	1.41***	1.25 to 1.60
Online chat (2 h+)	1.43***	1.31 to 1.56	1.87***	1.70 to 2.05
Email (2 h+)	1.93***	1.55 to 2.40	1.68***	1.31 to 2.14
Other PC use (2 h+)	1.38***	1.26 to 1.51	1.37***	1.25 to 1.51

*p<0.05; **p<0.01; ***p<0.001.
†Reference: SOL <60 min.