Table 1. Baseline Characteristics of the Study Population.
| Characteristic, Mean (SD) | Sample I | Sample II | ||
|---|---|---|---|---|
| Included (n = 3289) | Excluded (n = 1776)a | Included (n = 2998) | Excluded (n = 2067)a | |
| Age, y | 68.9 (9.9) | 71.8 (11.1)b | 68.2 (9.9) | 72.5 (10.7)b |
| Female , No. (%) | 1879 (57) | 1034 (58) | 1717 (57) | 1196 (58) |
| Systolic blood pressure, mm Hg | 145.9 (22.1) | 146.9 (24.0) | 145.6 (22.1) | 147.1 (23.7)b |
| Diastolic blood pressure, mm Hg | 84.7 (11.1) | 84.0 (11.7)b | 84.9 (11.1) | 83.7 (11.5)b |
| Blood pressure–lowering medication | 1450 (44) | 938 (53)b | 1283 (43) | 1107 (54)b |
| Body mass indexc | 27.5 (4.3) | 27.7 (4.5)b | 27.5 (4.2) | 27.6 (4.5) |
| Diabetes mellitus, No. (%) | 376 (11) | 250 (14)b | 337 (11) | 289 (14)b |
| Total cholesterol, mg/dL | 212.36 (42.47) | 204.63 (42.47)b | 212.36 (42.47) | 204.63 (42.47)b |
| High-density lipoprotein cholesterol, mg/dL | 57.92 (15.44) | 54.05 (15.44)b | 57.92 (15.44) | 54.05 (15.44)b |
| Smoking status, No. (%) | ||||
| Nonsmoker | 1032 (31) | 569 (32) | 951 (32) | 652 (32) |
| Former smoker | 1725 (52) | 892 (50)b | 1556 (52) | 1057 (51)b |
| Current smoker | 532 (16) | 306 (17)b | 491 (16) | 347 (17)b |
| Education | ||||
| Lower education | 1029 (31) | 624 (35)b | 964 (30) | 739 (36)b |
| Intermediate education | 1576 (48) | 811 (46) | 1545 (48) | 947 (46) |
| Higher education | 684 (21) | 310 (18)b | 705 (22) | 348 (17)b |
| Right eyes, No. (%) | 3126 (95) | NA | 2827 (94) | NA |
| Peripapillary retinal nerve fiber layer, μm | 95.3 (15.7) | NA | NA | NA |
| Macular ganglion cell, inner plexiform layer, μm | NA | NA | 70.4 (7.8) | NA |
| Prevalent dementia, No. (%) | 41 (1.2) | 54 (3.0)b | 34 (1.2) | 61 (3.0)b |
Abbreviation: NA, not applicable.
SI conversion factor: To convert cholesterol from mg/dL to mmol/L, multiple by 0.0259.
a
Missing values were not imputed. Percentage of missing values for all variables was less than 2%.
b
Age- and sex-adjusted mean differences (P < .05).
c
Body mass index is calculated as weight in kilograms divided by height in meters squared.