Table 2 Standardised prevalence of social isolation in relation to sociodemographic characteristics, lifestyle factors, and health outcomes in middle-aged and older adults in China, 2011–2018

Year

7900

38.09 (36.73–39.45)

7198

33.66(32.32–35.00)

6362

39.13(37.59–40.67)

8328

39.95(38.59–41.31)

 < 0.001

Sociodemographic subgroups

 Gender

   Male

4024

1513 (37.6)

3639

1213 (33.3)

3357

1241 (37.0)

4139

1615 (39.0)

0.01

   Female

3876

1496 (38.6)

3559

1210 (34.0)

3005

1243 (41.4)

4189

1714 (40.9)

 < 0.001

    χ2 and P value^c

-

-

-

-

 Age (years)

   45 ~ 

4408

25.26 (23.77–26.75)

3722

20.76 (19.28–22.24)

2904

23.01 (21.35–24.84)

3719

23.20 (21.65–24.76)

0.12

   60 ~ 

2233

49.25 (46.28–52.22)

2291

41.92 (39.23–44.62)

2192

45.96 (43.07–48.86)

2827

46.71 (44.19–49.23)

0.55

   70 ~ 

1035

61.79 (56.97–66.62)

981

61.79 (56.97–66.62)

1030

62.60 (57.67–67.54)

1458

62.85 (58.74–66.96)

0.54

   80 ~ 

224

77.59 (66.07–89.11)

204

70.12 (58.57–81.68)

236

77.67 (66.29–89.04)

324

73.09 (63.75–82.43)

0.56

   χ2 and P value^c

χ2 = 820.690, P < 0.001

χ2 = 803.653, P < 0.001

χ2 = 743.067, P < 0.001

χ2 = 954.233, P < 0.001

 Educational attainment

   Primary school or below

5035

45.96 (44.08–47.85)

4482

41.66 (39.75–43.56)

3902

47.49 (45.32–49.66)

5138

46.74 (44.85–48.63)

 < 0.001

   Middle and high school

2634

24.73 (22.81–26.64)

2553

20.62 (18.84–22.39)

2292

25.73 (23.59–27.87)

2987

29.42 (27.45–31.38)

 < 0.001

   College or above

231

17.78 (12.11–23.45)

163

13.85 (8.25–19.48)

168

19.99 (12.87–27.11)

203

15.29 (9.73–20.86)

 < 0.001

   χ2 and P value^c

χ2 = 372.670, P < 0.001

χ2 = 351.584, P < 0.001

χ2 = 279.889, P < 0.001

χ2 = 312.573, P < 0.001

 Residence

   Rural

4632

40.91 (39.06–42.75)

4274

36.79 (34.97–38.61)

3869

42.43 (40.36 -44.49)

4931

43.62 (41.78–45.47)

 < 0.001

   Urban

3268

33.88 (31.88–35.88)

2924

28.95 (27.00–30.91)

2493

33.77 (31.49 -36.05)

3397

28.95 (27.00–30.91)

0.002

   χ2 and P value^c

χ2 = 372.670, P < 0.001

χ2 = 351.584, P < 0.001

χ2 = 279.889, P < 0.001

χ2 = 312.573, P < 0.001

 Geographical location

   East

2976

35.24 (33.10–37.37)

2689

33.21 (31.03–35.38)

2374

36.85 (34.41–39.30)

2964

39.04 (36.79–41.29)

0.33

   Central

2451

35.20 (32.86–37.55)

2234

31.55 (29.21–33.88)

1918

35.61 (32.93–38.28)

2661

37.86 (35.53–40.20)

0.55

   West

2473

44.38 (41.75–47.00)

2275

36.33 (33.85–38.81)

2070

45.03 (42.13–47.93)

2703

43.04 (40.56–45.51)

0.17

   χ2 and P value^c

χ2 = 6.115, P = 0.047

χ2 = 1.162, P = 0.559

χ2 = 4.892, P = 0.087

χ2 = 0.329, P = 0.849

 Medical insurance

   Yes

7382

37.22 (35.83–38.61)

6964

33.29 (31.93–34.64)

5773

37.87 (36.28–39.46)

8113

39.55 (38.18–40.92)

 < 0.001

   No

518

39.04 (36.79–41.29)

234

44.56 (35.76–53.36)

589

50.98 (45.22–56.73)

215

54.46 (44.29–64.62)

 < 0.001

   χ2 and P value^c

χ2 = 0.648, P = 0.047

χ2 = 12.627, P = 0.047

χ2 = 38.338, P = 0.047

χ2 = 19.294, P = 0.047

 Pension(income)

   Yes

830

42.38 (37.95–46.81)

5879

34.34 (32.84–35.84)

4856

38.50 (36.75 -40.25)

7492

39.37 (37.94 -40.79)

 < 0.001

   No

7070

37.58 (36.15–39.01)

1319

30.63 (27.64–33.62)

1506

41.10 (37.87 -44.34)

836

45.11 (40.56 -49.65)

 < 0.001

   χ2 and P value^c

χ2 = 7.343, P = 0.007

χ2 = 6.652, P = 0.010

χ2 = 3.246, P = 0.072

χ2 = 10.258, P = 0.001

Lifestyle subgroups

 Internet use

   Yes

253

13.44 (8.92 -17.95)

381

11.64 (8.20–15.09)

417

12.93 (9.39–16.46)

1247

16.73 (14.44–19.01)

0.016

   No

7647

38.90 (37.51–40.30)

6817

34.90 (33.49–36.30)

5945

38.50 (39.50–40.50)

7081

44.08 (42.53–45.62)

 < 0.001

   χ2 and P value^c

χ2 = 67.347, P < 0.001

χ2 = 88.096, P < 0.001

χ2 = 109.367, P < 0.001

χ2 = 329.669, P < 0.001

 Sleep duration

   0 ~ 5 h

1286

49.80 (45.93 -53.68)

1187

42.87 (39.07 -46.67)

1064

47.71 (43.53 -51.89)

1568

49.40 (45.83–52.96)

0.26

   5 ~ 7 h

2730

37.24 (34.95 -39.53)

2879

31.19 (29.15 -33.23)

2278

36.68 (34.19 -39.18)

3275

37.11 (35.03–39.20)

0.11

   7 ~ 8 h

1549

30.48 (27.73 -33.23)

1435

28.22 (25.47 -30.97)

1132

32.84 (29.48 -36.20)

1428

34.24 (31.21–37.28)

0.004

   8 ~ 9 h

1710

35.76 (32.92 -38.59)

1254

32.63 (29.47 -35.79)

1343

37.52 (34.22 -40.82)

1463

39.70 (36.46–42.94)

0.004

   9 ~ h

625

42.88 (37.75 -48.01)

443

44.58 (38.36 -50.80)

545

48.89 (43.01 -54.77)

594

78.04 (70.67–85.42)

0.56

   χ2 and P value^c

χ2 = 54.990, P < 0.001

χ2 = 30.901, P < 0.001

χ2 = 29.833, P < 0.001

χ2 = 17.151, P < 0.001

 Smoking

   Yes

2527

41.55 (37.09–46.01)

2606

35.98 (31.70–40.26)

1878

40.23 (34.84–45.61)

2411

40.00 (35.68–44.32)

0.88

  No

5373

38.18 (36.40–39.96)

4592

34.83 (32.88–36.78)

4484

39.83 (37.91–41.75)

5917

40.15 (38.43–41.87)

 < 0.001

   χ2 and P value^c

χ2 = 8.229, P = 0.004

χ2 = 1.001, P = 0.317

χ2 = 0.100, P = 0.752

χ2 = 0.021, P = 0.884

 Alcohol consumption

  Yes

2691

33.47 (30.63–36.32)

2598

28.90 (26.41–31.40)

2393

34.15 (31.17–37.12)

2894

34.30 (31.71–36.90)

0.06

   No

5209

41.20 (39.34–43.05)

4600

37.11 (35.23–38.98)

3969

43.03 (40.89–45.17)

5434

43.74 (41.86–45.61)

 < 0.001

   χ2 and P value^c

χ2 = 44.585, P < 0.001

χ2 = 49.667, P < 0.001

χ2 = 49.316, P < 0.001

χ2 = 69.713, P < 0.001

Health status subgroups

 Multimorbidity

  Yes

2989

39.94 (37.68–42.21)

2993

35.00 (32.88–37.12)

2828

41.30 (38.93–43.67)

4789

42.44 (40.59–44.28)

 < 0.001

   No

4911

36.95 (35.25–38.65)

4205

32.71 (30.98–34.44)

3534

37.36 (35.33–39.39)

3539

36.42 (34.43–38.41)

0.55

   χ2 and P value^c

χ2 = 7.038, P = 0.008

χ2 = 4.199, P = 0.040

χ2 = 10.292, P = 0.001

χ2 = 30.638, P < 0.001

Self-rated health

   Good

1893

30.64 (28.13–33.15)

1789

29.91 (27.36–32.46)

1524

34.34 (31.35–37.33)

2142

32.43 (30.01–34.84)

0.05

   Fair

3938

36.69 (34.80–38.58)

3840

32.63 (30.82–34.43)

3376

38.03 (35.95–40.12)

4027

38.81 (36.88–40.73)

0.001

   Poor

2069

47.72 (44.73–50.70)

1569

40.70 (37.50–43.89)

1462

46.83 (43.32–50.34)

2159

49.37 (46.40–52.35)

0.04

   χ2 and P value^c

χ2 = 128.867, P < 0.001

χ2 = 48.156, P < 0.001

χ2 = 53.116, P < 0.001

χ2 = 132.418, P < 0.001

 Depression

   No depressive symptoms

4048

32.89 (31.11–34.68)

4812

31.56 (29.97–33.16)

3927

37.94 (35.97–39.90)

4427

37.91 (36.08–39.74)

 < 0.001

  Depressive symptoms

3479

42.28 (40.10–44.46)

2189

37.43 (34.81–40.05)

2131

39.29 (36.61–41.97)

3334

40.21 (38.03–42.39)

0.17

   Depression

373

55.21 (46.90–63.52)

197

47.70 (36.93–58.47)

304

54.28 (45.34–63.22)

567

53.76 (47.11–60.42)

1.00

   χ2 and P value^c

χ2 = 118.990, P < 0.001

χ2 = 40.560, P < 0.001

χ2 = 31.609, P < 0.001

χ2 = 53.125, P < 0.001

 BADL disability

   None

6683

34.94 (33.52–36.36)

6100

31.38 (29.97–32.78)

5191

36.52 (34.86–38.17)

6908

36.86 (35.43–38.29)

 < 0.001

   Mild

656

49.32 (43.94–54.70)

649

41.01 (36.06–45.97)

647

46.87 (41.55–52.19)

767

47.22 (42.22–52.23)

0.98

   Severe

561

62.11 (55.57–68.66)

449

53.83 (47.03–60.64)

524

54.97 (48.59–61.34)

653

63.98 (57.70–70.26)

0.37

   χ2 and P value^c

χ2 = 200.074, P < 0.001

χ2 = 112.207, P < 0.001

χ2 = 86.072, P < 0.001

χ2 = 201.980, P < 0.001