Table 5.
Comparison of IAS groups according to their frequencies of sleep problems
| IAS: <40 n (%) 836 (69) |
IAS: 40–69 n (%) 345 (28.5) |
IAS: >70 n (%) 31 (2.6) |
p* | |
|---|---|---|---|---|
| How often do you fall asleep in class? | ||||
| Never or rarely | 684 (74.1) | 227 (24.6) | 12 (1.3) | .001 |
| Occasionally | 128 (56.8) | 80 (36.5) | 11 (5) | *.001 |
| Frequently | 24 (34.3) | 38 (54.3) | 8 (11.4) | |
| How often do you feel sleepy during lessons | ||||
| Never or rarely | 437 (82.5) | 89 (16.8) | 4 (.8) | .001 |
| Occasionally | 293 (63.6) | 160 (34.7) | 8 (1.7) | *.001 |
| Frequently | 106 (48) | 96 (43.4) | 19 (8.6) | |
| How often do you have difficulty to fall asleep | ||||
| Never or rarely | 527 (73.7) | 175 (24.5) | 13 (1.8) | .001 |
| Occasionally | 207 (67.2) | 89 (28.9) | 12 (3.9) | *.001 |
| Frequently | 102 (54) | 81 (42.9) | 6 (3.2) | |
| How often do you feel sleepy and tired in the day | ||||
| Never or rarely | 244 (82.2) | 49 (16,5) | 4 (1.3) | .001 |
| Occasionally | 328 (71) | 130 (28.1) | 4 (.9) | *.001 |
| Frequently | 264 (58.3) | 166 (36.6) | 23 (5.1) | |
| How often do you have difficulty to wake up in the morning | ||||
| Never or rarely | 343 (78.6) | 82 (19) | 6 (1.4) | .001 |
| Occasionally | 215 (74.4) | 66 (22.8) | 8 (2.8) | *.001 |
| Frequently | 278 (56.5) | 197 (40) | 17 (3.5) | |
| How often do you have nightmares | ||||
| Never or rarely | 648 (70.4) | 253 (27.5) | 20 (2.2) | .006 |
| Occasionally | 135 (68.5) | 58 (28.4) | 4 (2) | *.003 |
| Frequently | 53 (56.4 | 34 (36.2) | 7 (7.4) | |
| How often do you talk in sleep (your or your families’ statement) | ||||
| Never or rarely | 703 (70.2) | 278 (27.8) | 20 (2) | .002 |
| Occasionally | 89 (69.5) | 34 (26.6) | 5 (3.9) | *.001 |
| Frequently | 44 (53) | 33 (39.8) | 6 (7.2) | |
Chi-square test and
*
Linear-by-Linear Association