Table 1 Characteristics of the participants (N = 1273)

Region

 Shanghai

281

22.1

 Zhejiang

505

39.7

 Henan

487

38.2

Age^a(Years)

 ≤ 44

616

48.5

 45–60

444

34.9

  ≥ 60

211

16.6

 Missing

2

0.2

Sex^a

 male

953

74.9

 female

309

24.3

 Missing

11

0.9

Ethnicity^a

 Han

1218

95.7

 Others

39

3.1

 Missing

16

1.3

Religious or not^a

 Yes

204

16.1

 No

1063

83.9

 Missing

6

0.5

Employment status^a

 Employed or student

665

52.8

 Unemployed or retired

595

47.2

 Missing

13

1.0

Marital status

 Married

574

45.1

 Single or divorced or widowed

699

54.9

Time of treatment^a (Years)

 < 1

152

11.9

 1–4

467

36.7

 5–9

305

24.0

 ≥ 10

321

25.2

 Missing

28

2.2