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Table 1 Sample characteristics at baseline (N = 6795)

From: Cognitive reserve over life course and 7-year trajectories of cognitive decline: results from China health and retirement longitudinal study

  Men Women
(N = 3459) (N = 3336)
Baseline cognition (mean, SD) 14.78 (5.49) 12.07 (6.00)
Cognitive reserve (mean, SD) 0.53 (1.62) −0.55 (1.62)
Mean age (years, SD) 67.67 (6.29) 67.78 (6.61)
Urban-rural residence (%)
 Urban 1330 (38.5) 1371 (41.1)
 Rural 2129 (61.5) 1965 (58.9)
Marital Status (%)
 Married 3020 (87.3) 2382 (71.4)
 Unmarried 439 (12.7) 953 (28.6)
 Missing 0 (0.0) 1 (0.0)
Alcohol drinking (%)
 Never 2076 (60.0) 3090 (92.6)
 < 1/month 44 (1.3) 14 (0.4)
 1–3/month 95 (2.7) 29 (0.9)
 1–6/week 212 (6.1) 36 (1.1)
 ≥1/day 690 (19.9) 60 (1.8)
 Missing 342 (9.9) 107 (3.2)
Smoking status (%)
 Never 935 (27.0) 2949 (88.4)
 Former 686 (19.8) 102 (3.1)
 Current 1728 (50.0) 259 (7.8)
 Missing 110 (3.2) 26 (0.8)
BMI (%)
 Underweight 290 (8.4) 275 (8.2)
 Normal 1719 (49.7) 1327 (39.8)
 Overweight 631 (18.2) 814 (24.4)
 Obese 192 (5.6) 342 (10.3)
 Missing 627 (18.1) 578 (17.3)
Hypertension (%)
 No 2348 (67.9) 2053 (61.5)
 Yes 1088 (31.5) 1252 (37.5)
 Missing 23 (0.7) 31 (0.9)
Diabetes (%)
 No 3195 (92.4) 2993 (89.7)
 Yes 235 (6.8) 300 (9.0)
 Missing 29 (0.8) 43 (1.3)
Heart disease (%)
 No 2895 (83.7) 2672 (80.1)
 Yes 531 (15.4) 626 (18.8)
 Missing 33 (1.0) 38 (1.1)
Stroke (%)
 No 3290 (95.1) 3193 (95.7)
 Yes 147 (4.2) 117 (3.5)
 Missing 22 (0.6) 26 (0.8)
Dyslipidemia (%)
 No 3055 (88.3) 2864 (85.9)
 Yes 335 (9.7) 396 (11.9)
 Missing 69 (2.0) 76 (2.3)
Hearing loss (%)
 No 2972 (85.9) 2917 (87.4)
 Yes 474 (13.7) 400 (12.0)
 Missing 13 (0.4) 19 (0.6)
Probable depressiona (%)
 No 2410 (69.7) 1863 (55.8)
 Yes 820 (23.7) 1235 (37.0)
 Missing 229 (6.6) 238 (7.1)
ADLs (%)
 0 2766 (80.0) 2434 (73.0)
 1 355 (10.3) 409 (12.3)
 2 132 (3.8) 204 (6.1)
 3 81 (2.3) 124 (3.7)
 4 58 (1.7) 74 (2.2)
 5 36 (1.0) 53 (1.6)
 6 20 (0.6) 24 (0.7)
 Missing 11 (0.3) 14 (0.4)
  1. Notes: ADLs activities of daily life, BMI body mass index, SD standard deviation
  2. a Probable depression was defined as having CES-D-10 score ≥ 12