Table 1.

Number of workers with sleep disturbance by general and occupational characteristics

			Sleep disturbance
	N	%	No	(%)	Yes	(%)	p-value*
Total	7112	100.0	6876	96.7	236	3.3
Gender
Female	2928	41.2	2833	96.8	95	3.2	0.771
Male	4184	58.8	4043	96.6	141	3.4
Age
<30	1481	20.8	1442	97.4	39	2.6	0.524
30-39	2057	28.9	1985	96.5	72	3.5
40-49	1880	26.4	1812	96.4	68	3.6
50-59	1155	16.2	1118	96.8	37	3.2
≥60	539	7.6	519	96.3	20	3.7
Educational status
Middle school or below	973	13.7	936	96.2	37	3.8	0.047
High school	2966	41.7	2886	97.3	80	2.7
College or above	3172	44.6	3053	96.2	119	3.8
Smoking
Non-smoker	3884	54.6	3751	96.6	133	3.4	0.847
Ex-smoker	697	9.8	674	96.7	23	3.3
Smoker	2531	35.6	2451	96.8	80	3.2
Drinking frequency
None	1938	27.3	1891	97.6	47	2.4	0.026
≤1 per week	2965	41.7	2862	96.5	103	3.5
≥2 per week	2208	31.1	2122	96.1	86	3.9
Employment status
Regular	4568	64.2	4430	97.0	135	3.0	0.061
Temporary	2544	35.8	2446	96.1	98	3.9
Job type
White collar	3081	43.3	2966	96.3	115	3.7	0.006
Service	1350	19.0	1324	98.1	26	1.9
Blue collar	2680	37.7	2586	96.5	94	3.5
Number of employees
<5	1526	22.3	1474	96.6	52	3.4	<0.001
5-49	3295	48.4	3210	97.4	85	2.6
50-299	1315	19.3	1246	94.8	69	5.2
≥300	689	10.0	667	96.8	22	3.2
Tenure (yr)
<1	1477	20.8	1431	96.9	46	3.1	0.764
1-9	4084	57.4	3943	96.5	141	3.5
≥10	1550	21.8	1501	96.8	49	3.2
Working time (hr/wk)
<40	1105	15.5	1083	98.0	22	2.0	<0.001
40-48	3801	53.5	3697	97.3	104	2.7
49-60	1624	22.8	1562	96.2	62	3.8
≥61	581	8.2	533	91.7	48	8.3
Shift work
No	6337	89.1	6153	97.1	184	2.9	<0.001
Yes	774	10.9	722	93.3	52	6.7
Hypertension
No	6622	93.1	6412	96.8	210	3.2	0.011
Yes	490	6.9	464	94.7	26	5.3
Obesity
No	6885	96.8	6667	96.8	218	3.2	<0.001
Yes	226	3.2	209	92.5	17	7.5
Depressive symptoms
No	6999	98.4	6811	97.3	188	2.7	<0.001
Yes	113	1.6	65	57.5	48	42.5

*based on a chi-squared test.