Table 1. Baseline characteristics of study populationa.
| Characteristic | Age categories | |||||
|---|---|---|---|---|---|---|
| <45 (n = 49,586) |
45–49 (n = 63, 062) |
50–54 (n = 72,472) |
55–59 (n = 85,636) |
60–64 (n = 114,183) |
65+ (n = 88,684) |
|
| Mean (SD) age, years | 42.3 (1.3) | 47.1 (1.4) | 52.1 (1.4) | 57.1 (1.4) | 61.9 (1.4) | 66.9 (1.5) |
| Female | 26703 (53.9) | 35199 (55.8) | 41252 (56.9) | 48055 (56.1) | 62550 (54.8) | 45394 (51.2) |
| White | 44174 (89.1) | 57344 (90.9) | 67391 (93.0) | 81423 (95.1) | 110497 (96.8) | 85719 (96.7) |
| Current smoking | 7371 (14.9) | 8496 (13.5) | 8760 (12.1) | 8960 (10.5) | 10431 (9.1) | 6980 (7.9) |
| Income | ||||||
| <18,000 | 5761 (11.6) | 7259 (11.5) | 8698 (12.0) | 12879(15.0) | 26818(23.5) | 28297(31.9) |
| 18,000–30,999 | 8095 (16.3) | 10368 (16.4) | 12684(17.5) | 17772(20.8) | 29992(26.3) | 23955(27.0) |
| 31,000–51,999 | 13956 (28.2) | 17207 (27.3) | 19234(26.5) | 21485(25.1) | 22689(19.9) | 12130(13.7) |
| 52,000–100,000 | 13289 (26.8) | 17056 (27.1) | 18687(25.8) | 17837(20.8) | 12166(10.7) | 4669(5.3) |
| '100,000+ | 3764 (7.6) | 4857 (7.7) | 5218(7.2) | 4426(5.2) | 2958(2.6) | 1065(1.2) |
| will not answer, missing | 4721 (9.5) | 6315 (10.0) | 7951(11.0) | 11237(13.1) | 19560(17.1) | 18568(20.9) |
| Education, level 4+ | 34366 (69.3) | 42471(67.4) | 47811(66.0) | 54006(63.1) | 63085(55.3) | 42024(47.4) |
| Employment status | ||||||
| currently employed | 43259 (87.2) | 55259 (87.6) | 61223 (84.5) | 61152 (71.4) | 43500 (38.1) | 11459 (12.9) |
| retired | 70 (0.1) | 302 (0.5) | 2343 (3.2) | 13066 (15.3) | 63763 (55.8) | 75789 (85.5) |
| other/not reported | 6257 (12.6) | 7501 (11.9) | 8906 (12.3) | 11418 (13.3) | 6920 (6.1) | 1436 (1.6) |
| Mean (SD) Townsend deprivation score | -0.7 (3.3) | -1.0 (3.2) | -1.2 (3.1) | -1.4 (3.0) | -1.6 (2.9) | -1.6 (2.9) |
| Mean (SD) moderate to vigorous physical activity minutes/week | 76.5 (96.2) | 74.3 (96.0) | 71.3 (94.8) | 71.2 (95.6) | 77.5 (97.2) | 80.3 (97.5) |
| Mean (SD) alcohol drinks/week | 1.1 (1.4) | 1.2 (1.4) | 1.2 (1.5) | 1.2 (1.4) | 1.2 (1.4) | 1.1 (1.4) |
| Apoe ε4 carriers | 11631 (28.5) | 15158 (29.1) | 16989 (28.5) | 19624 (28.2) | 26217 (28.2) | 20109 (28.2) |
aCross-sectional study population. Data drawn from 2006–10. Values are numbers (percentages) unless stated otherwise. All characteristic values are significantly different across age-categories (P<0.0001 for all but Apoe: P = 0.002).