Table 1 Descriptive statistics of full sample and subgroups

Social structural factors at baseline

Age at baseline***

72.52 ± 6.01

72.97 ± 6.28

72.04 ± 5.66

< 0.001

Education***

< 0.001

Illiteracy

7390 (45.99)

5515 (65.93)

1875 (24.34)

Primary school or above

8678 (54.01)

2850 (34.07)

5828 (75.66)

Missing

25

17 

8 

Residence^ns

0.355

Rural

9210 (57.23)

4768 (56.88)

4442 (57.61)

Urban

6883 (42.77)

3614 (43.12)

3269 (42.39)

Missing

0 

0 

0 

Income***

2.99 ± 0.65

2.96 ± 0.64

3.01 ± 0.67

< 0.001

Living with family member***

< 0.001

No

2238 (13.91)

1371 (16.36)

867 (11.25)

Yes

13,851 (86.09)

7009 (83.64)

6842 (88.75)

Missing

4 

2 

2 

Have a spouse***

< 0.001

No

6129 (38.09)

4299 (51.29)

1830 (23.73)

Yes

9963 (61.91)

4082 (48.71)

5881 (76.27)

Missing

1 

1 

 0

Healthcare accessibility^ns

0.217

No

1500 (9.32)

804 (9.59)

696 (9.03)

Yes

14,593 (90.68)

7578 (90.41)

7015 (90.97)

Missing

0 

0 

0 

Behavioral health factors at baseline

Current smoking***

< 0.001

No

11,737 (72.96)

7596 (90.66)

4141 (53.72)

Yes

4350 (27.04)

783 (9.34)

3567 (46.28)

Missing

6 

3 

3

Current drinking***

< 0.001

No

12,276 (76.30)

7541 (89.97)

4735 (61.43)

Yes

3814 (23.70)

841 (10.03)

2973 (38.57)

Missing

3

0

3

Social activities ***

1.48 ± 1.06

1.40 ± 0.97

1.58 ± 1.13

< 0.001

Health status factors at baseline

BADL**

0.006

No

15,094 (93.86)

7819 (93.36)

7275 (94.39)

Yes

988 (6.14)

556 (6.64)

432 (5.61)

Missing

11 

7 

4 

IADL***

< 0.001

No

10,334 (64.26)

4766 (56.87)

5568 (72.29)

Yes

5748 (35.74)

3614 (43.13)

2134 (27.71)

Missing

11 

2 

9

Chronic diseases***

1.00 (0.00 ~ 2.00)

1.00 (0.00 ~ 2.00)

1.00 (0.00 ~ 1.00)

< 0.001

Self-rated Health

2005***

3.48 ± 0.93

3.42 ± 0.93

3.54 ± 0.93

< 0.001

2008***

3.42 ± 0.95

3.36 ± 0.94

3.48 ± 0.96

< 0.001

2011***

3.32 ± 0.98

3.25 ± 1.00

3.39 ± 0.95

< 0.001

2014**

3.29 ± 0.93

3.26 ± 0.92

3.33 ± 0.93

0.005