Table 1.
Characteristics of the study population.
| Characteristics | All | Good sleep quality | Poor sleep quality | |
|---|---|---|---|---|
| N = 832 | N = 401 | N = 431 | P value | |
| n (%) | n (%) | n (%) | ||
| Age (mean ± SD, years) | 21.9 ± 3.4 | 21.6 ± 3.2 | 22.2 ± 3.5 | 0.231 |
| Age (years) | ||||
| 18 | 91 (10.9) | 48 (12.0) | 43 (10.0) | 0.373 |
| 19 | 132 (15.9) | 64 (16.0) | 68 (15.8) | |
| 20 | 121 (14.5) | 63 (15.8) | 58 (13.5) | |
| 21 | 99 (11.9) | 52 (13.0) | 47 (10.9) | |
| ≥22 | 388 (46.6) | 173 (43.2) | 215 (49.9) | |
| Sex | ||||
| Male | 241 (29.0) | 131 (32.8) | 110 (25.5) | 0.022 |
| Female | 590 (71.0) | 269 (67.2) | 321 (74.5) | |
| Cigarette smoking status | ||||
| Never | 325 (39.1) | 172 (45.6) | 153 (38.9) | 0.159 |
| Former | 77 (9.3) | 37 (9.8) | 40 (10.2) | |
| Current | 368 (44.2) | 168 (44.6) | 200 (50.9) | |
| Alcohol consumption | ||||
| Low (0–4 drinks/month) | 167 (20.1) | 78 (32.5) | 89 (32.7) | 0.966 |
| Moderate (5–15 drinks/month) | 158 (19.0) | 73 (30.4) | 85 (31.2) | |
| High (≥16 drinks) | 187 (22.5) | 89 (37.1) | 98 (36.0) | |
| Weekly consumption of stimulants | ||||
| No | 356 (42.8) | 196 (50.3) | 160 (40.1) | |
| Yes | 433 (52.0) | 194 (49.7) | 239 (59.9) | 0.004 |
| Body mass index (kg/m2) | ||||
| Underweight (<18.5) | 10 (1.2) | 3 (0.8) | 7 (1.7) | |
| Normal (18.5–24.9) | 444 (53.4) | 225 (57.8) | 219 (52.6) | 0.300 |
| Overweight (25.0–29.9) | 227 (28.2) | 101 (26.0) | 126 (30.3) | |
| Obese (≥30.0) | 124 (14.9) | 60 (15.4) | 64 (15.4) | |
| Any physical activity | ||||
| No | 279 (33.5) | 140 (38.3) | 139 (37.5) | 0.826 |
| Yes | 458 (55.0) | 226 (61.7) | 232 (62.5) |
*Due to missing data, percentages may not add up to 100%; physical activity includes moderate and vigorous physical activity.