Table 2.

Sleep variables and use of screens before and during the lockdown

	BEFORE the lockdown  N (%)	DURING the lockdown N (%)	p value
Sleep latency (min)
< 30  < 60  > 60	230 (86.8)   29 (10.9)     6 (2.3)	169 (63.7)   52 (19.6)   44 (16.6)	< 0.0001
Bedtime weekdays
20:00–21:00 21:00–22:15 22:15–00:30 00:30–1:45 Later than 1:45	13 (4.9) 121 (45.7) 122 (46.0)     8 (3.0)     1 (0.4)	2 (0.8)    32 (12.1)  145 (54.7)    58 (21.9)    28 (10.6)	< 0.0001
Bedtime weekends
20:00–21:00 21:00–22:15 22:15–00:30 00:30–1:45 Later than 1:45	0 (0.0)    25 (9.4)  155 (58.5)    74 (27.9)    11 (4.2)	0 (0.0)     12 (4.6)   131 (49.4)     86 (32.4)     36 (13.6)	< 0.0001
Wake time weekdays
5:00–6:30 6:30–7:45 7:45–9:45 9:45–11:00 Later than 11:00	7 (2.6)   168 (63.4)     90 (34.0)       0 (0.0)       0 (0.0)	1 (0.4)      10 (3.8)    175 (66.0)      54 (20.4)      25 (9.4)	< 0.0001
Wake time weekends
5:00–6:30 6:30–7:45 7:45–9:45 9:45–11:00 Later than 11:00	1 (0.4)       7 (2.6)   110 (41.5)   117 (44.2)     30 (11.3)	1 (0.4)        3 (1.1)      87 (32.8)    116 (43.8)      58 (21.9)	< 0.0001
Nighttime awakenings	98 (37.0)	109 (41.1)	< 0.0001
Naps	44 (16.6)	48 (18.1)	0.271
Xanthines (> 3 d/week)	25 (9.5)	38 (14.4)	0.002
Frequent diurnal hypersomnolence	74 (27.9)	91 (34.3)	0.014
Hours of screen time per day
0–2 h/d 2–4 h/d 4–6 h/d 6–8 h/d  > 8 h/d	130 (49.1)   101 (38.1)     20 (7.5)       9 (3.4)       5 (1.9)	7 (2.3)      59 (22.3)    106 (40.0)      50 (18.9)      43 (16.2)	< 0.0001
Online homework (sometimes or always)	166 (62.6)	262 (98.8)	< 0.0001
Online classes (sometimes or always)	22 (8.4)	250 (94.3)	< 0.0001

Significant p values (< 0.05) are in bold