Table 4.

Comparison of sleep parameters among secondary school students pre- and during COVID.

Sleep Parameters	Pre-COVID (n = 230) Mean (SD)	COVID (n = 212) Mean (SD)	P
School days
Bedtime, hh:mm	23:13 (±72 min)	23:24 (±82 min)	.13
Sleep onset time, hh:mm	23:27 (±73 min)	23:46 (±91 min)	.016
Sleep midpoint time, hh:mm	3:03 (±43 min)	3:15 (±55 min)	.015
Wake up time, hh:mm	6:39 (±30 min)	6:43 (±46 min)	.28
Sleep latency, hh:mm	0:14 (±12 min)	0:22 (±31 min)	< .001
Sleep duration, hh:mm	7:11 (±70 min)	6:56 (±94 min)	.061
Nonschool days
Bedtime, hh:mm	00:01 (±84 min)	00:28 (±85 min)	.006
Sleep onset time, hh:mm	00:16 (±85 min)	00:51 (±125 min)	< .001
Sleep midpoint time, hh:mm	4:41 (±81 min)	5:05 (±100 min)	.005
Wake up time, hh:mm	9:20 (±105 min)	9:43 (±112 min)	.030
Sleep latency, hh:mm	00:14 (±13 min)	00:22 (±35 min)	.002
Sleep duration, hh:mm	9:03 (±102 min)	8:51 (±105 min)	.23
Social jetlag, hh:mm	1:37 (±104 min)	1:50 (±137 min)	.049

SD = standard deviation.