Table 4 Baseline characteristics of the participants according to trajectories of global cognitive function in middle-aged and older adults from CHARLS
Characteristic | Trajectory of global cognitive function | p value | ||
|---|---|---|---|---|
Class 1, persistently low (n = 1550) | Class 2, persistently moderate (n = 3194) | Class 3, persistently high (n = 3460) | ||
Age (years), mean ± SD | 60.45 ± 6.31 | 60.26 ± 6.41 | 59.77 ± 6.35 | < 0.001 |
Male sex, n (%) | 483 (31.2) | 1677 (52.5) | 2129 (61.5) | < 0.001 |
Educational level, n (%) | < 0.001 | |||
No formal education | 1305 (84.2) | 1590 (49.8) | 656 (19.0) | |
Primary school | 175 (11.3) | 910 (28.5) | 926 (26.8) | |
Middle or high school | 68 (4.4) | 660 (20.7) | 1542 (44.6) | |
College or above | 2 (0.1) | 34 (1.1) | 336 (9.7) | |
Married, n (%) | 1316 (84.9) | 2826 (88.5) | 3168 (91.6) | < 0.001 |
Rural residence, n (%) | 1175 (75.8) | 2106 (65.9) | 1625 (47.0) | < 0.001 |
High household income, n (%) | 295 (19.0) | 740 (23.2) | 1316 (38.0) | < 0.001 |
Current smoker, n (%) | 383 (24.7) | 1134 (35.5) | 1240 (35.8) | < 0.001 |
Current drinker, n (%) | 389 (25.1) | 1096 (34.3) | 1371 (39.6) | < 0.001 |
Poor self-report of health, n (%) | 552 (35.6) | 906 (28.4) | 649 (18.8) | < 0.001 |
Depressive symptoms, n (%) | 775 (50.0) | 1239 (38.8) | 840 (24.3) | < 0.001 |
Restriction on ADL, n (%) | 330 (21.3) | 502 (15.7) | 325 (9.4) | < 0.001 |
Visual impairment, n (%) | 135 (8.7) | 203 (6.4) | 126 (3.6) | < 0.001 |
Hearing impairment, n (%) | 159 (10.3) | 254 (8.0) | 187 (5.4) | < 0.001 |
Comorbidity, n (%)* | 0.715 | |||
0 | 212 (13.7) | 441 (13.8) | 513 (14.8) | |
1 | 362 (23.4) | 765 (24.0) | 814 (23.5) | |
≥ 2 | 976 (63.0) | 1988 (62.2) | 2133 (61.6) | |
BMI (kg/m2), mean ± SD | 23.01 ± 3.71 | 23.41 ± 4.07 | 23.92 ± 3.85 | < 0.001 |
Social activity scores, n (%) | < 0.001 | |||
0 | 991 (63.9) | 2034 (63.7) | 1894 (54.7) | |
1–2 | 256 (16.5) | 551 (17.3) | 653 (18.9) | |
≥ 3 | 303 (19.5) | 609 (19.1) | 913 (26.4) | |
Intellectual activity scores, n (%) | < 0.001 | |||
0 | 1377 (88.8) | 2605 (81.6) | 2425 (70.1) | |
1–2 | 123 (7.9) | 438 (13.7) | 632 (18.3) | |
≥ 3 | 50 (3.2) | 151 (4.7) | 403 (11.6) | |
Global cognitive scores, mean ± SD | 7.50 ± 1.92 | 10.74 ± 2.36 | 14.49 ± 2.13 | < 0.001 |
Mental intactness scores, mean ± SD | 4.63 ± 1.85 | 7.28 ± 2.10 | 9.73 ± 1.57 | < 0.001 |
Episodic memory scores, mean ± SD | 2.86 ± 1.31 | 3.45 ± 1.39 | 4.76 ± 1.47 | < 0.001 |