Table 1.
UK Biobank Sample Characteristics
| Measure | Complete Data (N=9200) | Incomplete Data (N=2059) | P Valuea | Effect Sizeb |
|---|---|---|---|---|
| Sociodemographic characteristics at baseline | ||||
| Age (y), mean±SD | 55.3±7.4 | 54.8±7.2 | 0.006c | 0.07 |
| Sex, n (%) | ||||
| Female | 5272 (57.3%) | 1213 (58.9%) | 0.18 | 0.01 |
| Male | 3928 (42.7%) | 846 (41.1%) | ||
| Race/ethnicity, n (%) | ||||
| Mixed/other | 70 (0.8%) | 24 (1.2%) | 0.17 | 0.02 |
| Asian | 88 (1.0%) | 26 (1.3%) | ||
| Black | 35 (0.4%) | 7 (0.3%) | ||
| White | 9007 (97.9%) | 1999 (97.1%) | ||
| Missing | 0 | 3 (0.2%) | ||
| Education, n (%) | ||||
| Attended college | 4699 (51.1%) | 787 (38.2%) | <0.001c | 0.03 |
| No college | 4501 (48.9%) | 899 (43.7%) | ||
| Missing | 0 | 373 (18.1%) | ||
| Employment status, n (%) | ||||
| Employed | 6062 (65.9%) | 1428 (69.4%) | <0.001c | 0.17 |
| Retired | 2681 (29.1%) | 460 (22.3%) | ||
| Not employed/not retired | 457 (5.0%) | 106 (5.2%) | ||
| None of the above/prefer not to answer | 0 | 62 (3.0%) | ||
| Missing | 0 | 3 (0.2%) | ||
| Shift work, n (%) | ||||
| Yes | 734 (8.0%) | 189 (9.2%) | 0.03a | 0.02 |
| No | 8466 (92.0%) | 1805 (87.7%) | ||
| Missing | 0 | 65 (3.2%) | ||
| Residence, n (%) | ||||
| Urban | 7792 (84.7%) | 1775 (86.2%) | <0.001c | 0.06 |
| Rural | 1408 (15.3%) | 201 (9.8%) | ||
| Missing | 0 | 83 (4.0%) | ||
| Alcohol frequency intake, n (%) | ||||
| Daily or almost daily | 2013 (21.9%) | 437 (21.2%) | <0.001c | 0.05 |
| Three or 4 times a wk | 2636 (28.7%) | 528 (25.6%) | ||
| Once or twice a wk | 2361 (25.7%) | 509 (24.7%) | ||
| One to 3 times a mo | 992 (10.8%) | 248 (12.0%) | ||
| Special occasions only/never | 1198 (13.0%) | 333 (16.2%) | ||
| Prefer not to answer | 0 | 1 (0.1%) | ||
| Missing | 0 | 3 (0.2%) | ||
| Depression status, n (%) | ||||
| Yes | 458 (5.0%) | 72 (3.5%) | <0.001c | 0.07 |
| No | 1293 (14.1%) | 186 (9.0%) | ||
| Unknown | 7449 (81.0%) | 1801 (87.5%) | ||
| Family history of CVD, n (%) | ||||
| Yes | 5089 (55.3%) | 1030 (50.0%) | 0.24 | 0.02 |
| No | 4083 (44.4%) | 880 (42.7%) | ||
| Do not know/prefer not to answer | 28 (0.3%) | 9 (0.4%) | ||
| Missing | 0 | 140 (6.8%) | ||
| Cardiovascular outcomes at 5‐y follow‐up | ||||
| Myocardial infarction, n (%) | ||||
| Yes | 43 (0.5%) | 14 (0.7%) | 0.29 | 0.01 |
| No | 9153 (99.5%) | 2039 (99.0%) | ||
| Prefer not to answer | 4 (0.04%) | 2 (0.1%) | ||
| Missing | 0 | 4 (0.2%) | ||
| Angina, n (%) | ||||
| Yes | 55 (0.6%) | 19 (0.9%) | 0.16 | 0.02 |
| No | 9141 (99.4%) | 2034 (98.8%) | ||
| Prefer not to answer | 4 (0.04%) | 2 (0.1%) | ||
| Missing | 0 | 4 (0.2%) | ||
| Stroke, n (%) | ||||
| Yes | 46 (0.5%) | 15 (0.7%) | 0.28 | 0.02 |
| No | 9150 (99.5%) | 2038 (99.0%) | ||
| Prefer not to answer | 4 (0.04%) | 2 (0.1%) | ||
| Missing | 0 | 4 (0.2%) | ||
| Any CVD event, n (%) | ||||
| Yes | 135 (1.5%) | 46 (2.2%) | 0.03a | 0.03 |
| No | 9061 (98.5%) | 2007 (97.5%) | ||
| Prefer not to answer | 4 (0.04%) | 2 (0.1%) | ||
| Missing | 0 | 4 (0.2%) | ||
| Cardiovascular medication use at 5‐y follow‐up | ||||
| Cholesterol‐lowering medication use, n (%) | ||||
| Yes | 700 (7.6%) | 244 (11.9%) | <0.001c | 0.06 |
| No | 8500 (92.4%) | 1811 (88.0%) | ||
| Missing | 0 | 4 (0.2%) | ||
| BP medicine use, n (%) | ||||
| Yes | 602 (6.5%) | 223 (10.8%) | <0.001c | 0.06 |
| No | 8598 (93.5%) | 1832 (89.0%) | ||
| Missing | 0 | 4 (0.2%) | ||
| Insulin use, n (%) | ||||
| Yes | 4 (0.04%) | 7 (0.3%) | <0.001c | 0.04 |
| No | 9196 (99.9%) | 2048 (99.5%) | ||
| Missing | 0 | 4 (0.2%) | ||
| Any CVD medication use, n (%) | ||||
| Yes | 1090 (11.9%) | 369 (17.9%) | <0.001c | 0.07 |
| No | 8110 (88.2%) | 1686 (81.9%) | ||
| Missing | 0 | 4 (0.2%) | ||
| Self‐reported sleep measures at baseline | ||||
| Sleep duration, n (%) | ||||
| Short | 1899 (20.6%) | 505 (24.5%) | <0.001c | 0.04 |
| Adequate | 6777 (73.7%) | 1417 (68.8%) | ||
| Long | 524 (5.7%) | 134 (6.5%) | ||
| Missing | 0 | 3 (0.2%) | ||
| Circadian preference, n (%) | ||||
| Morning | 2359 (25.6%) | 407 (19.8%) | <0.001c | 0.05 |
| Intermediate | 6004 (65.3%) | 1053 (51.1%) | ||
| Evening | 837 (9.1%) | 226 (11.0%) | ||
| Missing | 0 | 373 (18.1%) | ||
| AHA simple‐7 measures at baseline | ||||
| Physical activity, n (%) | ||||
| Ideal | 5636 (61.3%) | 163 (7.9%) | 0.27 | 0.02 |
| Intermediate | 3346 (36.4%) | 87 (4.2%) | ||
| Poor | 10 (0.1%) | 1 (0.1%) | ||
| Do not know/prefer not to answer | 208 (2.3%) | 9 (0.4%) | ||
| Missing | 0 | 1799 (87.4%) | ||
| Diet, n (%) | ||||
| Ideal | 10 (0.1%) | 0 | 0.05 | 0.02 |
| Intermediate | 4889 (53.1%) | 1046 (50.8%) | ||
| Poor | 4301 (46.8%) | 1010 (49.1%) | ||
| Missing | 0 | 3 (0.2%) | ||
| Tobacco use at baseline, n (%) | ||||
| Ideal | 5906 (64.2%) | 1295 (62.9%) | 0.005c | 0.03 |
| Intermediate | 2766 (30.1%) | 600 (29.1%) | ||
| Poor | 517 (5.6%) | 158 (7.7%) | ||
| Prefer not to answer | 11 (0.1%) | 3 (0.2%) | ||
| Missing | 0 | 3 (0.2%) | ||
| BMI, n (%) | ||||
| Ideal | 2026 (22.0%) | 403 (19.6%) | <0.001c | 0.05 |
| Intermediate | 3956 (43.0%) | 792 (38.5%) | ||
| Poor | 3218 (35.0%) | 845 (41.0%) | ||
| Missing | 0 | 19 (0.9%) | ||
| BP, n (%) | ||||
| Ideal | 1669 (18.1%) | 347 (16.9%) | 0.51 | 0.01 |
| Intermediate | 3719 (40.4%) | 727 (35.3%) | ||
| Poor | 3543 (38.5%) | 736 (35.8%) | ||
| Missing | 269 (2.9%) | 249 (12.1%) | ||
AHA indicates American Heart Association; BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease.
a
P<0.05.
b
Effect sizes based on Cohen's d (small: 0.20, medium 0.50, large: 0.80) for continuous variables and Cramer's V (negligible to weak: 0–0.20, moderate: 0.20–0.39, strong: 0.40–1) for categorical variables.
c
P<0.01.