Table 1.
Characteristics of cases and matched controls, and ORs for first VTE (univariate analyses adjusted for age, sex, and GP practice by matching)
| Characteristic | Cases
|
Controlsa
|
OR (95% CIs) |
|---|---|---|---|
| Number (%) | Number (%) | ||
| Exacerbation frequency | 3,594 (100.0) | 10,782 (100.0) | |
| Infrequent | 2,547 (70.9) | 7,765 (72.0) | 1 |
| Frequent | 1,047 (29.1) | 3,017 (28.0) | 1.06 (0.97, 1.15) |
| Sex | 3,594 (100.0) | 10,782 (100.0) | Matched |
| Men | 1,870 (52.0) | 5,610 (52.0) | |
| Women | 1,724 (48.0) | 5,172 (48.0) | |
| Index age (years) | 3,594 (100.0) | 10,782 (100.0) | Matched |
| Under 60 | 268 (7.5) | 800 (7.4) | |
| 60–69 | 876 (24.4) | 2,643 (24.5) | |
| 70–79 | 1,418 (39.5) | 4,280 (39.7) | |
| 80 and over | 1,032 (28.7) | 3,059 (28.4) | |
| Smoking statusb | 3,593 (100.0) | 10,773 (100.0) | |
| Nonsmoker | 369 (10.3) | 1,089 (10.1) | 1.00 (0.88, 1.14) |
| Ex-smoker | 1,634 (45.5) | 4,829 (44.8) | 1 |
| Current smoker | 1,590 (44.3) | 4,855 (45.1) | 0.96 (0.89, 1.05) |
| BMIb | 3,494 (100.0) | 10,526 (100.0) | |
| Underweight | 193 (5.5) | 826 (7.9) | 0.83 (0.70, 0.98) |
| Normal weight | 1,109 (31.7) | 3,910 (37.1) | 1 |
| Overweight | 1,123 (32.1) | 3,393 (32.2) | 1.18 (1.07, 1.30) |
| Obese | 1,069 (30.6) | 2,397 (22.8) | 1.61 (1.45, 1.77) |
| Family history | 3,594 (100.0) | 10,782 (100.0) | |
| No | 2,597 (72.3) | 7,870 (73.0) | 1 |
| Yes | 997 (27.4) | 2,912 (27.0) | 1.04 (0.95, 1.14) |
| Hypertension | 3,594 (100.0) | 10,782 (100.0) | |
| No | 1,764 (49.1) | 5,436 (50.42) | 1 |
| Yes | 1,830 (50.9) | 5,346 (49.6) | 1.06 (0.98, 1.14) |
| Dyslipidaemia | 3,594 (100.0) | 10,782 (100.0) | |
| No | 2,873 (79.9) | 8,541 (79.2) | 1 |
| Yes | 721 (20.1) | 2,241 (20.8) | 0.95 (0.86, 1.05) |
| Diabetes | 3,594 (100.0) | 10,782 (100.0) | |
| No | 2,998 (83.4) | 8,997 (83.4) | 1 |
| Yes | 596 (16.6) | 1,785 (16.6) | 1.00 (0.90, 1.11) |
| Atrial fibrillationb | 3,594 (100.0) | 10,781 (100.0) | |
| No | 3,129 (87.1) | 9,593 (89.0) | 1 |
| Yes | 465 (12.9) | 1,188 (11.0) | 1.21 (1.08, 1.36) |
| Heart failureb | 3,594 (100.0) | 10,780 (100.0) | |
| No | 3,059 (85.1) | 9,650 (89.5) | 1 |
| Yes | 535 (14.9) | 1,130 (10.5) | 1.52 (1.36, 1.70) |
| CVDs (composite)c | 3,594 (100.0) | 10,782 (100.0) | |
| No CVDs | 2,558 (71.2) | 7,931 (73.6) | 1 |
| 1 CVD | 719 (20.0) | 2,041 (18.9) | 1.10 (1.00, 1.21) |
| 2 or more CVDs | 317 (8.8) | 810 (7.5) | 1.23 (1.07, 1.41) |
Notes:
a
Including duplicates. Since control selection was concurrent with replacement, some cases were picked as a control before they became a case and some people were selected as a control more than once. Hence among the control group there are duplicated individuals. There are 10,119 individual controls.
b
Some missing data.
c
Myocardial infarction, angina, peripheral arterial disease, acute coronary syndrome.
Abbreviations: BMI, body mass index; CI, confidence interval; CVD, cardiovascular disease; GP, general practitioner; OR, odds ratio; VTE, venous thromboembolism.