Table 1.
Characteristics (data are expressed as counts (percentages) except when specified otherwise) of 11,732 community-dwelling Chinese older people at baseline by cohort
| 2002 cohort (n = 6626) | 2008 cohort (n = 5106) | Total (n = 11,732) | |
|---|---|---|---|
| Age, years, mean (standard deviation) | 81.7 (10.9) | 83.6 (11.8) | 82.5 (11.3) |
| Age group | |||
| 65–79 years | 3009 (45.4) | 1808 (35.4) | 4817 (41.1) |
| ≥ 80 years | 3617 (54.6) | 3298 (64.6) | 6915 (58.9) |
| Male | 2999 (45.3) | 2265 (44.4) | 5264 (44.9) |
| No schooling | 3857 (58.2) | 3052 (59.8) | 6909 (58.9) |
| White-collar workers | 1536 (23.2) | 951 (18.6) | 2487 (21.2) |
| Urban residents | 2695 (40.7) | 1783 (34.9) | 4478 (38.2) |
| Married | 2771 (41.8) | 2150 (42.1) | 4921 (41.9) |
| Living with family members | 5509 (83.1) | 4235 (82.9) | 9744 (83.1) |
| Smoking status | |||
| Never | 4213 (63.6) | 3373 (66.1) | 7586 (64.7) |
| Past | 963 (14.5) | 697 (13.7) | 1660 (14.1) |
| Current | 1437 (21.7) | 1033 (20.2) | 2470 (21.1) |
| Current alcohol consumption | 1549 (23.4) | 1011 (19.8) | 2560 (21.8) |
| Currently exercises | 2403 (36.3) | 1555 (30.5) | 3958 (33.7) |
| Hypertension | 1003 (15.1) | 1043 (20.4) | 2046 (17.4) |
| Diabetes | 114 (1.7) | 137 (2.7) | 251 (2.1) |
| Heart disease | 558 (8.4) | 408 (8.0) | 966 (8.2) |
| Cerebrovascular disease | 272 (4.1) | 253 (5.0) | 525 (4.5) |
| Respiratory disease | 794 (12.0) | 464 (9.1) | 1258 (10.7) |
| Body mass index | |||
| Underweight (< 18.5) | 2683 (40.5) | 1733 (33.9) | 4416 (37.6) |
| Normal (18.5–23.9) | 3017 (45.5) | 2379 (46.6) | 5396 (46.0) |
| Overweight (24–27.9) | 634 (9.6) | 622 (12.2) | 1256 (10.7) |
| Obese (≥ 28) | 204 (3.1) | 245 (4.8) | 449 (3.8) |
| Psychological distress | |||
| 1st quartile | 1205 (18.2) | 884 (17.3) | 2089 (17.8) |
| 2st quartile | 1870 (28.2) | 1419 (27.8) | 3289 (28.0) |
| 3st quartile | 1804 (27.2) | 1295 (25.4) | 3099 (26.4) |
| 4st quartile | 1358 (20.5) | 985 (19.3) | 2343 (20.0) |
| Baseline MMSE score, points† | 27 [23, 29] | 27 [21, 29] | 27 [22, 29] |
| Baseline cognitive impairment‡ | 1740 (26.3) | 1680 (32.9) | 3420 (29.2) |
| Final MMSE score, points†,§ | 26 [19, 29] | 26 [18, 29] | 26 [19, 29] |
| Final cognitive impairment‡ | 2414 (36.4) | 1979 (38.8) | 4393 (37.4) |
| Rate of change in MMSE score, points/year†,¶ | 0.3 [− 0.3, 1.7] | 0.0 [− 0.7, 1.4] | 0.0 [− 0.6, 1.6] |
| Cognitive decline# | |||
| Improvement | 2197 (33.2) | 1909 (37.4) | 4106 (35.0) |
| Stable | 1094 (16.5) | 790 (15.5) | 1884 (16.1) |
| Slow decline | 1631 (24.6) | 1196 (23.4) | 2827 (24.1) |
| Rapid decline | 1704 (25.7) | 1211 (23.7) | 2915 (24.8) |
| Vital status | |||
| Survived | 4144 (62.5) | 3335 (65.3) | 7479 (63.7) |
| Deceased | 2482 (37.5) | 1771 (34.7) | 4253 (36.3) |
| Duration of follow-up, years† | |||
| Survived | 3.17 [3.08, 3.25] | 2.75 [2.50, 2.83] | 3.08 [2.75, 3.17] |
| Deceased | 1.58 [1.00, 2.33] | 1.33 [0.75, 2.00] | 1.50 [0.92, 2.25] |
Abbreviation: MMSE Mini-Mental State Examination
Note: Missing data: 34 for schooling, 27 for occupation, 16 for smoking, 8 for drinking, 10 for exercising, 346 for hypertension, 342 for diabetes, 328 for heart disease, 304 for cerebrovascular disease, 264 for respiratory disease, 215 for BMI, 912 for symptom of psychological distress
†Data are expressed as the median [25th percentile, 75th percentile]
‡Cognitive impairment: MMSE score < 24 points
§MMSE re-examined at 3 years after baseline measurement
¶Rate of change in MMSE score = (baseline MMSE score − final MMSE score)/the interval between two examinations (years)
#Cognitive decline was defined according to the rate of change in MMSE score. Improvement—rate of change in MMSE score less than zero; stable—rate of change in MMSE score equal to zero; slow decline—rate of change in MMSE score greater than zero but equal to or less than the median of the rate of change showing decline; rapid decline—rate of change in MMSE score greater than the median of the rate of change showing decline