Total cohort (12–17 years) | Total cohort divided into age groups | Sub-cohort (12–17 years)a | Baseline vs. Follow-Up | ||||||
---|---|---|---|---|---|---|---|---|---|
n | n = 419 | 12 years (n = 97) | 13 years (n = 157) | 14 years (n = 91) | 15–17 (n = 73) | Baseline (n = 286) | Follow-Up (n = 286) | P value | |
Sleeping hours | 402 | 8.3 ± 0.8 | 8.7 ± 0.8 | 8.4 ± 0.7 | 8.0 ± 0.9 | 7.8 ± 0.8 | 8.3 ± 0.8 | – | – |
6–7.5 h | 65 (16) | 5 (5) | 15 (10) | 23 (26) | 22 (34) | 44 (16) | – | ||
8 h | 169 (42) | 34 (35) | 72 (47) | 35 (40) | 28 (43) | 112 (40) | – | ||
8.5–10 h | 168 (42) | 58 (60) | 65 (43) | 30 (34) | 15 (23) | 123 (44) | – | ||
Sleeping problems: go back to sleep | 419 | 0.111 | |||||||
Never | 88 (21) | 26 (27) | 32 (20) | 18 (20) | 12 (16) | 60 (21) | 46 (16) | ||
Rarely, few times/year | 138 (33) | 31 (32) | 51 (32) | 34 (37) | 22 (30) | 92 (32) | 86 (30) | ||
Some few times/months | 129 (31) | 23 (24) | 51 (32) | 27 (30) | 28 (38) | 95 (33) | 108 (38) | ||
Several times/week | 58 (14) | 14 (14) | 23 (15) | 11 (12) | 10 (14) | 36 (13) | 38 (13) | ||
Every day | 6 (1) | 3 (3) | 1 (1) | 1 (1) | 1 (1) | 3 (1) | 7 (3) | ||
Sleeping problems: woke up | 417 | 0.576 | |||||||
Never | 160 (38) | 34 (35) | 64 (41) | 33 (36) | 29 (40) | 108 (38) | 109 (38) | ||
Rarely, few times/year | 177 (42) | 39 (41) | 60 (38) | 42 (46) | 36 (49) | 123 (43) | 115 (40) | ||
Some few times/months | 68 (16) | 20 (21) | 29 (18) | 13 (14) | 6 (8) | 48 (17) | 46 (16) | ||
Several times/week | 10 (2) | 3 (3) | 4 (3) | 2 (2) | 1 (1) | 5 (2) | 12 (4) | ||
Every day | 2 (1) | 0 (0) | 0 (0) | 1 (1) | 1 (1) | 1 (0) | 3 (1) | ||
Feel tired in daily activities | 417 | 0.025 | |||||||
Never | 47 (11) | 16 (16) | 22 (14) | 8 (9) | 1 (1) | 31 (11) | 21 (7) | ||
Rarely, few times/year | 149 (36) | 42 (43) | 59 (38) | 31 (34) | 17 (23) | 100 (35) | 73 (25) | ||
Some few times/months | 131 (31) | 22 (23) | 52 (33) | 35 (39) | 22 (30) | 97 (34) | 116 (41) | ||
Several times/week | 70 (17) | 16 (16) | 20 (13) | 10 (11) | 24 (33) | 44 (15) | 59 (21) | ||
Every day | 20 (5) | 1 (1) | 4 (2) | 6 (7) | 9 (12) | 13 (5) | 17 (6) | ||
Impaired sleep with daytime consequences | 419 | 34 (8) | 7 (7) | 8 (5) | 8 (9) | 11 (15) | 19 (7) | 25 (9) | 0.327 |
Impaired sleep without daytime consequence | 419 | 31 (7) | 8 (8) | 18 (11) | 4 (4) | 1 (1) | 21 (7) | 26 (9) | 0.522 |