Table 1 Characteristics of participants aged 60 or above from the three population-based datasets
WGDS | CHNS | CLHLS | |
|---|---|---|---|
Survey year(s) | 2014–2018 | 2009 | 2008–2014 |
Sample size at baseline | 4579 | 2440 | 1236 |
Sample size at follow-up | 3870 | – | 420 |
Mean age at baseline, years (SD) | 67.7 (6.3) | 68.9 (6.8) | 86.6 (12.3) |
Age range at baseline, years | 60–93 | 60–99 | 62–110 |
Men, n (%) | 2200 (48.0) | 1149 (47.1) | 493 (39.9) |
BMI at baseline, mean (SD) | 23.3 (2.6) | 23.3 (3.7) | 20.0 (3.8) |
Diabetes at baseline, n (%) | 367 (8.0) | 331 (13.6) | 133 (10.8) |
Hypertension at baseline, n (%) | 2463 (53.8) | 670 (27.5) | 173 (14.0) |
Habitual tea drinker, n (%) | 1571 (34.3) | 911 (37.3) | 435 (35.2) |
Current cigarette smoker, n (%) | 1193 (26.1) | 621 (25.5) | 266 (21.5) |
Current alcohol drinker, n (%) | 1035 (22.6) | 637 (26.1) | 233 (18.9) |
Fasting plasma glucose at baseline, mmol/L, mean (SD) | 5.6 (1.1) | 5.7 (1.7) | 5.4 (1.9) |
Type of tea, n (%) | |||
Green tea | 1408 (89.6) | – | – |
Black or Oolong tea | 91 (5.8) | – | – |
other | 72 (4.6) | – | – |
Frequency, n (%) | |||
≥ 6 times/week | 1398 (88.99) | 717 (78.9) | 265 (60.9) |
< 6 times/week | 173 (11.01) | 192 (21.1) | 170 (39.1) |
Education level, n (%) | |||
Primary education and below | 3954 (86.4) | 1749 (71.7) | 1165 (94.3) |
Secondary schooling and above | 625 (13.6) | 691 (28.3) | 71 (5.7) |