Table 1.

Mean sleep duration and proportion of individuals reporting insomnia symptoms according to selected characteristics of participants.

	N	Mean sleep duration (h)	Insomnia symptoms (%)	Daytime naps (%)	Frequent snoring (%)	Short sleep (≤6 h) (%)	Long sleep (≥9 h) (%)
All	512,891	7.38	16.8	20.9	22.0	23.1	15.9
Age (year)
30-39	77,804	7.73	10.8	18.2	13.6	12.9	19.6
40-49	152,748	7.5	13.8	19.4	19.9	19.0	16.1
50-59	157,556	7.29	18.5	20.4	26.4	25.3	14.4
60-69	91,773	7.14	21.7	24.2	26.0	30.8	14.6
70-79	33,010	6.98	24.8	26.5	21.8	37.2	15.0
Gender
Men	210,259	7.43	13.5	24.9	28.9	21.7	15.6
Women	302,632	7.35	19.2	18.0	17.5	24.2	16.0
Region
Rural	286,705	7.51	18.7	8.5	20.4	21.2	20.3
Urban	226,186	7.21	14.6	36.4	24.1	25.6	10.3
Highest education
No formal school/Primary school	260,437	7.37	17.9	18.8	22.5	24.7	17.1
Middle school/High school	222,440	7.4	15.8	22.9	22.0	22.0	15.4
Technical school/College/University	30,014	7.42	14.0	40.5	21.8	16.7	12.4
Annual household income (yuan)
<10,000	144,832	7.37	20.1	18.1	21.1	25.5	18.4
10,000–19,999	149,013	7.41	16.9	20.0	22.2	23.0	17.1
20,000–34,999	126,721	7.39	15.9	23.5	22.6	22.5	15.1
≥35,000	92,325	7.4	15.5	26.8	23.8	21.4	14.9
Marital status
Married	464,608	7.4	16.4	21.1	22.3	22.6	16.0
Widowed	36,572	7.14	23.7	18.9	19.9	30.7	13.5
Separated/divorced	7945	7.2	20.4	20.6	20.8	28.4	15.1
Never married	3766	6.92	17.6	18.2	14.1	25.2	15.9
Living alone
No	498,335	7.39	16.6	20.9	22.1	22.9	16.0
Yes	14,556	6.92	23.4	19.8	17.7	31.7	13.9
Occupation
Manual worker	286,402	7.31	16.5	16.3	21.6	22.6	15.0
Not in employment	138,460	7.43	17.9	24.9	24.2	23.6	18.4
Office worker	66,173	7.36	14.9	25.7	23.9	21.4	13.5
Other or not stated	8267	7.19	17.2	20.1	24.5	23.1	19.3
Unemployed	13,589	7.13	21.1	22.6	21.8	25.2	16.5
Smoking status
Never regular smoker	346,773	7.38	16.9	21.1	21.0	23.1	15.7
Ex-regular smoker	30,563	7.09	21.0	23.7	28.6	33.5	15.1
Regular smoker	135,555	7.36	20.1	20.7	26.4	24.6	17.5
Alcohol
Never regular drinker	235,199	7.41	16.9	20.8	21.1	23.0	17.0
Ex-regular drinker	9256	6.95	23.2	23.8	23.2	27.5	16.0
Occasional drinker	192,284	7.38	16.8	21.1	22.2	22.8	15.8
Weekly drinker	76,152	7.37	18.3	25.0	24.0	23.7	15.8
Physical activity (METa-h/day)
<10	121,598	7.44	18.0	22.3	23.5	24.0	19.6
10-29	262,808	7.39	16.5	21.6	22.1	22.5	15.7
≥30	128,485	7.28	16.5	17.6	21.7	24.5	13.4
BMIb(kg/mb)
<18.5	22,373	7.23	22.4	18.6	10.9	27.8	14.8
18.5–24.99	321,586	7.37	17.4	20.3	17.2	23.4	15.7
25–29.99	147,965	7.43	15.0	22.4	31.1	22.0	16.6
≥30	20,965	7.44	13.6	23.4	48.4	22.3	17.5
Waist Circumference (mm)
200–699	71,879	7.30	20.3	18.2	12.5	25.5	15.3
700–799	187,350	7.36	17.5	19.5	16.1	23.7	15.7
800–899	167,260	7.40	15.7	21.5	24.6	22.5	15.9
900–1499	86,402	7.43	14.5	23.3	38.0	22.1	16.9
SBPc(mmHg)
<110	70,853	7.34	17.9	19.8	16.6	23.9	15.0
(110,120)	92,407	7.36	17.0	20.3	18.7	23.5	15.4
(120,130)	113,683	7.37	16.7	20.5	21.0	23.3	15.5
(130,140)	87,936	7.39	16.5	21.2	23.5	22.8	16.1
≥140	148,012	7.41	16.6	21.5	27.7	22.7	16.8

Adjusted for age, region and sex (where appropriate).

^aMET: Metabolic Equivalent Task.

^bBMI: Body Mass Index.

^cSystolic Blood Pressure.