Basic information, sociodemographic characteristics and lifestyle characteristics
Variables | Normal-sleep quality group (n=160) | Low-sleep quality group (n=138) | χ2 | P value | Effect size | 95% CI | |
Lower | Upper | ||||||
Age (years) | 20.8±1.4 | 20.7±1.3 | 0.666 | −0.025 | 0.000 | 0.000 | |
Age at menarche (years) | 12.5±1.7 | 12.5±1.5 | 0.839 | 0.012 | 0.000 | 0.000 | |
Body mass index (kg/m2) | 20.5±2.6 | 20.8±2.6 | 0.884 | 0.008 | −0.521 | 0.459 | |
Part-time job | |||||||
Yes | 135 (84.4) | 123 (89.1) | 1.442 | 0.230 | 0.070 | 0.004 | 0.168 |
No | 25 (15.6) | 15 (10.9) | |||||
Living status | |||||||
Alone | 57 (35.6) | 46 (33.3) | 0.172 | 0.678 | 0.024 | 0.002 | 0.143 |
With others | 103 (64.4) | 92 (66.7) | |||||
Alcohol intake | |||||||
Low | 145 (90.6) | 129 (93.5) | 0.815 | 0.367 | 0.052 | 0.003 | 0.169 |
High | 15 (9.4) | 9 (6.5) | |||||
Smoking | |||||||
No | 152 (95.0) | 133 (96.4) | 0.337 | 0.562 | 0.034 | 0.002 | 0.149 |
Yes | 8 (5.0) | 5 (0.6) | |||||
Breakfast | |||||||
Eating | 114 (71.3) | 81 (58.7) | 5.163 | 0.023* | 0.132 | 0.016 | 0.245 |
Not eating | 46 (28.7) | 57 (41.3) | |||||
Eating between meals | |||||||
Eating | 101 (63.1) | 95 (68.8) | 1.075 | 0.300 | 0.060 | 0.004 | 0.172 |
Not eating | 59 (36.9) | 43 (31.2) | |||||
Caffeine consumption (≥3 times/week) | |||||||
Yes | 74 (46.3) | 57 (41.3) | 0.736 | 0.391 | 0.050 | 0.031 | 0.234 |
No | 86 (53.7) | 81 (58.7) | |||||
Studying until going to bed (≥3 times/week) | |||||||
Yes | 37 (23.1) | 32 (23.2) | 0.000 | 0.990 | 0.001 | 0.016 | 0.183 |
No | 123 (76.9) | 106 (76.8) | |||||
Watching TV until going to bed (≥3 times/week) | |||||||
Yes | 44 (27.5) | 29 (21.0) | 1.685 | 0.194 | 0.075 | 0.023 | 0.206 |
No | 116 (72.5) | 109 (79.0) | |||||
Screen time | |||||||
Leisure (min/day) | 256.4±204.2 | 252.1±144.0 | 0.578 | 0.032 | −30.000 | 30.000 | |
Study (min/day) | 105.9±129.8 | 107.1±124.4 | 0.265 | 0.064 | −20.000 | 0.000 |
Data are expressed as mean±SD, or n (%).
*Statistically significant.