Table 2.

The basic characteristics of the participants at baseline in the Lanxi cohort study

Characteristic	Overall (n=5132)		Urban (n=3327)		Rural (n=1805)		P value*
	Mean or N	SD or %	Mean or N	SD or %	Mean or N	SD or %
Sex
Male	1988	38.7	1260	37.87	728	40.3	0.084
Female	3144	61.3	2067	62.13	1077	59.7
Age (yrs)
18–29	222	4.33	176	5.29	46	2.55	<0.001
30–39	581	11.32	392	11.78	189	10.47
40–49	1112	21.67	749	22.51	363	20.11
50–59	1472	28.68	932	28.01	540	29.92
60–69	1257	24.49	760	22.84	497	27.53
70–80	488	9.51	318	9.56	170	9.42
Mean age (yrs)	53.04	12.77	52.42	13.15	54.17	11.94	<0.001
Ethnics
Han	5013	97.7	3250	97.7	1763	97.7	0.749
Minority	10	0.2	6	0.2	4	0.2
Unknown	109	2.1	71	2.1	38	2.1
Education
Illiteracy	922	17.8	478	14.4	444	24.6	<0.001
Primary school	1061	20.7	510	15.3	551	30.5
Middle/high school	2488	48.5	1783	53.6	705	39.1
College or above	549	10.7	485	14.6	64	3.6
Unknown	112	2.2	71	2.1	41	2.3
Marital status
Unmarried	177	3.5	130	3.9	47	2.6	<0.001
Married	4570	89.1	2913	87.6	1657	91.8
Ex-married	276	5.4	216	6.5	60	3.3
Unknown	109	2.1	68	2.0	41	2.3
Smoking
Never smoker	3942	76.8	2551	76.7	1391	77.1	0.206
Current smoker	808	15.7	519	15.6	289	16.0
Former smoker	269	5.2	188	5.7	81	4.5
Unknown	113	2.2	69	2.1	44	2.4
Drinking
Never	2723	53.1	1775	53.4	948	52.5	<0.001
<12/year	973	19.0	581	17.5	392	21.7
≥12/year	1204	23.5	832	25.0	372	20.6
Former drinker	117	2.3	68	2.0	49	2.7
Unknown	115	2.2	71	2.1	44	2.4

*Comparison between the urban and rural participants, Student’s t-test for continuous variables and χ² test for categorical variables. yrs, years.