Table 1.

Characteristics of male and female participants according to sleep quality^a.

	Sleep quality			Trend pb
	Poor	Normal	Good
Male participants
n	1090	3409	1752
BMI (kg/m2)	23.1 (22.9-23.4)c	23.2 (23.0-23.3)	23.3 (23.1-23.6)	0.269
Grade (%)
First year	30.5	30.6	31.2	0.637
Second year	30.3	29.2	27.6	0.108
Third year	25.6	25.3	25.2	0.836
Fourth year	13.7	14.9	16.0	0.092
Minority race (%)	5.9	6.5	6.6	0.465
Physical activity (≥23METs h/week; %)	35.6	36.1	39.2	0.033
Living status (dormitory; %)	93.1	92.1	92.5	0.689
Smoking status (%)
Smoker	20.6	19.8	19.3	0.420
Drinking status (%)
Drinking everyday	5.9	6.6	4.7	0.086
Drink occasionally	30.8	27.8	30.3	0.937
Non-drinker	63.3	65.6	65.1	0.437
Depressive symptom (%)	18.3	19.4	19.6	0.430
Regular consumption of Hypnotic drug (%)	1.3	1.6	0.6	0.053
Female participants
n	755	2100	1019
BMI (kg/m2)	21.2 (20.9-21.5)	21.2 (21.0-21.4)	21.2 (20.9-21.4)	0.799
Grade (%)
First year	32.5	27.7	28.1	0.066
Second year	24.4	28.4	28.5	0.078
Third year	23.3	25.2	27.9	0.026
Fourth year	19.9	18.7	15.6	0.016
Minority race (%)	7.7	7.3	7.9	0.784
Physical activity (≥23METs h/week; %)	33.6	34	37.4	0.079
Living status (dormitory; %)	92.7	90.4	90.7	0.181
Smoking status (%)
Smoker	2.0	2.0	2.6	0.379
Drinking status (%)
Drinking everyday	5.2	5.0	3.3	0.051
Drink occasionally	21.5	18.6	26.4	0.003
Non-drinker	73.4	76.5	70.3	0.064
Depressive symptom (%)	18.0	19.5	18.8	0.725
Regular consumption of Hypnotic drug (%)	2.0	1.8	0.9	0.052

^aBMI: body mass index; PA: physical activity.

^bObtained using ANOVA for continuous variables and x² test for proportional variables.

^cMean; 95% CI in parentheses (all such values).