Table 1 Baseline characteristics of the study population in CHARLS (N = 10,976) and SHARE (N = 40,499)
Characteristic | Total | Non-SCP & Non-ICP | SCP & Non-ICP | Non-SCP & ICP | SCP & ICP | P-value |
|---|---|---|---|---|---|---|
China Health and Retirement Longitudinal Study (CHARLS) | ||||||
 N | 10,976 | 7064 | 2772 | 628 | 512 |  |
 Age (years) | 57.7 ± 8.7 | 57.1 ± 8.6 | 57.8 ± 8.4 | 60.6 ± 9.6 | 61.9 ± 9.0 | <0.001 |
 Female (%) | 5480 (49.9) | 3192 (45.2) | 1534 (55.3) | 396 (63.1) | 358 (69.9) | <0.001 |
 Rural (%) | 6543 (59.6) | 3839 (54.3) | 1915 (69.1) | 412 (65.6) | 377 (73.6) | <0.001 |
 Married (%) | 9842 (89.7) | 6389 (90.4) | 2496 (90.0) | 534 (85.0) | 423 (82.6) | <0.001 |
 Education level (%) |  |  |  |  |  | <0.001 |
  Illiterate | 2287 (20.8) | 1028 (14.6) | 730 (26.3) | 269 (42.8) | 260 (50.8) |  |
  ≤ Primary school | 4611 (42.0) | 2830 (40.1) | 1284 (46.3) | 280 (44.6) | 217 (42.4) |  |
  Junior high school | 2557 (23.3) | 1941 (27.5) | 528 (19.0) | 61 (9.7) | 27 (5.3) |  |
  ≥ High school | 1521 (13.9) | 1265 (17.9) | 230 (8.3) | 18 (2.9) | 8 (1.6) |  |
 Household income (%) |  |  |  |  |  | <0.001 |
  T1 | 3041 (32.1) | 1617 (26.6) | 979 (40.5) | 232 (43.2) | 213 (47.9) |  |
  T2 | 3193 (33.7) | 2046 (33.7) | 826 (34.1) | 172 (32.0) | 149 (33.5) |  |
  T3 | 3240 (34.2) | 2410 (39.7) | 614 (25.4) | 133 (24.8) | 83 (18.7) |  |
 Smoking status (%) |  |  |  |  |  | <0.001 |
  Never | 6517 (59.4) | 4034 (57.1) | 1706 (61.5) | 418 (66.6) | 359 (70.1) |  |
  Former | 960 (8.7) | 625 (8.8) | 241 (8.7) | 58 (9.2) | 36 (7.0) |  |
  Current | 3499 (31.9) | 2405 (34.0) | 825 (29.8) | 152 (24.2) | 117 (22.9) |  |
 Drinking status (%) |  |  |  |  |  | <0.001 |
  Never | 6543 (59.6) | 4053 (57.4) | 1734 (62.6) | 420 (66.9) | 336 (65.6) |  |
  Former | 865 (7.9) | 525 (7.4) | 244 (8.8) | 45 (7.2) | 51 (10.0) |  |
  Current | 3568 (32.5) | 2486 (35.2) | 794 (28.6) | 163 (26.0) | 125 (24.4) |  |
 BMI (kg/m2) |  |  |  |  |  | 0.001 |
  <18.5 | 522 (5.5) | 293 (4.9) | 145 (5.9) | 46 (8.2) | 38 (8.1) |  |
  18.5–23.9 | 4956 (52.4) | 3094 (51.8) | 1304 (53.0) | 300 (53.4) | 258 (55.2) |  |
  24–27.9 | 2862 (30.2) | 1853 (31.0) | 735 (29.9) | 153 (27.2) | 121 (25.9) |  |
  ≥28 | 1127 (11.9) | 736 (12.3) | 278 (11.3) | 63 (11.2) | 50 (10.7) |  |
 Sleep duration (hours) |  |  |  |  |  | <0.001 |
  ≤5.0 | 3015 (27.6) | 1640 (23.3) | 982 (35.6) | 193 (30.9) | 200 (39.6) |  |
  5.1–6.0 | 2384 (21.8) | 1613 (22.9) | 565 (20.5) | 115 (18.4) | 91 (18.0) |  |
  6.1–7.0 | 2264 (20.7) | 1592 (22.6) | 479 (17.4) | 108 (17.3) | 85 (16.8) |  |
  7.1–8.0 | 2425 (22.2) | 1688 (24.0) | 507 (18.4) | 149 (23.9) | 81 (16.0) |  |
  >8.0 | 837 (7.7) | 508 (7.2) | 222 (8.1) | 59 (9.5) | 48 (9.5) |  |
 Physical activity level (%) |  |  |  |  |  | 0.016 |
  T1 | 1544 (33.2) | 991 (33.5) | 373 (30.5) | 95 (36.8) | 85 (38.8) |  |
  T2 | 1553 (33.4) | 1013 (34.3) | 396 (32.4) | 75 (29.1) | 69 (31.5) |  |
  T3 | 1558 (33.5) | 952 (32.2) | 453 (37.1) | 88 (34.1) | 65 (29.7) |  |
 Depressive symptoms (%) | 2708 (24.7) | 1162 (16.4) | 1129 (40.7) | 172 (27.4) | 245 (47.9) | <0.001 |
 Restriction on ADL (%) | 1274 (11.6) | 626 (8.9) | 423 (15.3) | 92 (14.6) | 133 (26.0) | <0.001 |
 Chronic conditions (%) |  |  |  |  |  |  |
  Hypertension | 2794 (25.5) | 1726 (24.4) | 768 (27.7) | 145 (23.1) | 155 (30.3) | <0.001 |
  Diabetes | 701 (6.4) | 438 (6.2) | 198 (7.1) | 35 (5.6) | 30 (5.9) | 0.262 |
  Heart-related diseases | 1365 (12.4) | 782 (11.1) | 439 (15.8) | 66 (10.5) | 78 (15.2) | <0.001 |
  Stroke | 227 (2.1) | 124 (1.8) | 64 (2.3) | 17 (2.7) | 22 (4.3) | <0.001 |
  Cancer | 107 (1.0) | 54 (0.8) | 37 (1.3) | 7 (1.1) | 9 (1.8) | 0.016 |
 Cognitive function (z-score) |  |  |  |  |  |  |
  Episodic memory | 0.00 ± 1.00 | 0.17 ± 1.00 | −0.23 ± 0.91 | −0.41 ± 0.98 | −0.58 ± 0.83 | <0.001 |
  Executive function | 0.00 ± 1.00 | 0.22 ± 0.92 | −0.27 ± 1.01 | −0.54 ± 0.98 | −0.88 ± 0.95 | <0.001 |
  Global cognitive function | 0.00 ± 1.00 | 0.24 ± 0.94 | −0.31 ± 0.95 | −0.60 ± 0.94 | −0.94 ± 0.83 | <0.001 |
Survey of Health, Ageing and Retirement in Europe (SHARE) | ||||||
 N | 40,499 | 29,177 | 9657 | 1021 | 644 |  |
 Age (years) | 64.6 ± 9.4 | 63.6 ± 9.1 | 66.9 ± 9.5 | 65.7 ± 10.1 | 69.4 ± 10.2 | <0.001 |
 Female (%) | 23,274 (57.5) | 16,509 (56.6) | 5796 (60.0) | 581 (56.9) | 388 (60.2) | <0.001 |
 Rural (%) | 13,883 (35.8) | 9859 (35.3) | 3453 (37.1) | 362 (37.4) | 209 (33.8) | 0.006 |
 Married (%) | 30,498 (75.3) | 22,280 (76.4) | 7048 (73.0) | 749 (73.4) | 421 (65.4) | <0.001 |
 Education level (%) |  |  |  |  |  | <0.001 |
  Primary school | 7860 (19.4) | 4606 (15.8) | 2644 (27.4) | 314 (30.8) | 296 (46.0) |  |
  Middle school | 7694 (19.0) | 5118 (17.5) | 2218 (23.0) | 199 (19.5) | 159 (24.7) |  |
  High school | 16,181 (40.0) | 12,265 (42.0) | 3443 (35.7) | 329 (32.2) | 144 (22.4) |  |
  ≥ College | 8764 (21.6) | 7188 (24.6) | 1352 (14.0) | 179 (17.5) | 45 (7.0) |  |
 Household income (%) |  |  |  |  |  | <0.001 |
  T1 | 13,499 (33.3) | 8316 (28.5) | 4363 (45.2) | 434 (42.5) | 386 (59.9) |  |
  T2 | 13,500 (33.3) | 9806 (33.6) | 3182 (33.0) | 331 (32.4) | 181 (28.1) |  |
  T3 | 13,500 (33.3) | 11,055 (37.9) | 2112 (21.9) | 256 (25.1) | 77 (12.0) |  |
 Smoking status (%) |  |  |  |  |  | <0.001 |
  Never | 20,972 (52.5) | 14,836 (51.5) | 5211 (54.8) | 550 (54.6) | 375 (59.2) |  |
  Former | 11,294 (28.3) | 8241 (28.6) | 2649 (27.9) | 253 (25.1) | 151 (23.9) |  |
  Current | 7674 (19.2) | 5716 (19.9) | 1646 (17.3) | 205 (20.3) | 107 (16.9) |  |
 Drinking status (%) |  |  |  |  |  | <0.001 |
  Never | 3602 (9.9) | 2359 (8.9) | 1012 (11.9) | 142 (15.6) | 89 (15.8) |  |
  Former | 3832 (10.5) | 2356 (8.9) | 1265 (14.9) | 107 (11.7) | 104 (18.4) |  |
  Current | 28,987 (79.6) | 21,747 (82.2) | 6204 (73.2) | 664 (72.7) | 372 (65.8) |  |
 BMI (kg/m2) |  |  |  |  |  | <0.001 |
  <18.5 | 428 (1.1) | 287 (1.0) | 113 (1.2) | 17 (1.7) | 11 (1.8) |  |
  18.5–24.9 | 13,976 (35.5) | 10,364 (36.5) | 3094 (33.1) | 340 (34.9) | 178 (29.1) |  |
  25–29.9 | 16,307 (41.5) | 11,772 (41.5) | 3873 (41.4) | 395 (40.6) | 267 (43.7) |  |
  ≥30 | 8608 (21.9) | 5953 (21.0) | 2278 (24.3) | 222 (22.8) | 155 (25.4) |  |
 Vigorous physical activity (%) |  |  |  |  |  | <0.001 |
  >1 per week | 14,509 (35.8) | 11,398 (39.1) | 2690 (27.9) | 313 (30.7) | 108 (16.8) |  |
  1 per week | 5917 (14.6) | 4519 (15.5) | 1189 (12.3) | 135 (13.2) | 74 (11.5) |  |
  <1 per week | 20,073 (49.6) | 13,260 (45.4) | 5778 (59.8) | 573 (56.1) | 462 (71.7) |  |
 Moderate physical activity (%) |  |  |  |  |  | <0.001 |
  >1 per week | 28,763 (71.0) | 21,458 (73.5) | 6345 (65.7) | 632 (61.9) | 328 (50.9) |  |
  1 per week | 5550 (13.7) | 3937 (13.5) | 1368 (14.2) | 138 (13.5) | 107 (16.6) |  |
  <1 per week | 6186 (15.3) | 3782 (13.0) | 1944 (20.1) | 251 (24.6) | 209 (32.5) |  |
 Depressive symptoms (%) | 10,641 (26.3) | 6074 (20.8) | 3911 (40.5) | 289 (28.3) | 367 (57.0) | <0.001 |
 Restriction on ADL (%) | 3510 (8.7) | 1829 (6.3) | 1391 (14.4) | 122 (11.9) | 168 (26.1) | <0.001 |
 Chronic conditions (%) |  |  |  |  |  |  |
  Hypertension | 17,039 (42.1) | 11,503 (39.4) | 4744 (49.1) | 427 (41.8) | 365 (56.7) | <0.001 |
  Diabetes | 4861 (12.0) | 3143 (10.8) | 1482 (15.3) | 117 (11.5) | 119 (18.5) | <0.001 |
  Heart-related diseases | 5792 (14.3) | 3511 (12.0) | 1963 (20.3) | 147 (14.4) | 171 (26.6) | <0.001 |
  Stroke | 1684 (4.2) | 938 (3.2) | 659 (6.8) | 35 (3.4) | 52 (8.1) | <0.001 |
  Cancer | 2835 (7.0) | 1928 (6.6) | 811 (8.4) | 52 (5.1) | 44 (6.8) | <0.001 |
 Cognitive function (z-score) |  |  |  |  |  |  |
  Episodic memory | 0.00 ± 1.00 | 0.14 ± 0.98 | −0.34 ± 0.96 | −0.27 ± 1.02 | −0.88 ± 0.90 | <0.001 |
  Executive function | 0.00 ± 1.00 | 0.11 ± 1.01 | −0.25 ± 0.90 | −0.30 ± 0.99 | −0.70 ± 0.75 | <0.001 |
  Global cognitive function | 0.00 ± 1.00 | 0.14 ± 0.99 | −0.33 ± 0.91 | −0.34 ± 0.99 | −0.88 ± 0.76 | <0.001 |