Table 1.
Characteristics of People with Atrial Fibrillation (Cases) and Controls
| Atrial fibrillation cases | Controls | |
|---|---|---|
| N = 1410 | N = 2203 | |
| Characteristic | na (%) | na (%) |
| Median age, years (IQR)b | 74 (66, 80) | 68 (59, 76) |
| Femaleb | 911 (64.6) | 1208 (54.8) |
| Treated hypertensionb | 1043 (74.0) | 1710 (77.6) |
| White race | 1306/1399 (93.4) | 1918/2166 (88.6) |
| Median body mass index, kg/m2 (IQR) | 29 (25, 34) | 29 (25, 33) |
| Obese (BMI ≥30 kg/m2) | 595 (42.2) | 938 (42.6) |
| Hypercholesterolemia | 428 (30.7) | 611 (27.7) |
| Valvular heart disease | 89 (6.3) | 45 (2.0) |
| Coronary artery diseasec | 322 (22.8) | 358 (16.3) |
| Chronic congestive heart failure | 128 (9.1) | 64 (2.9) |
| Current smoker | 118/1409 (8.4) | 220/2201 (10.0) |
| Median systolic blood pressure, mm Hg (IQR) | 137 (122, 150) | 136 (122, 148) |
| Median diastolic blood pressure, mm Hg (IQR) | 78 (70, 84) | 80 (70, 84) |
| Median cholesterol, mg/dL (IQR) | 5.78 (5.10, 6.55) | 5.72 (5.00, 6.55) |
| Median HDL cholesterol, mg/dL (IQR) | 1.37 (1.11, 1.74) | 1.35 (1.09, 1.66) |
| Median length of GH enrollment, years (IQR) | 21 (11, 31) | 20 (11, 30) |
| Median number of visits in prior year (IQR) | 6 (3, 11) | 4 (2, 8) |
Abbreviations: BMI, body mass index; GH, Group Health; HDL, high-density lipoprotein; IQR, interquartile range; mm Hg, millimeters mercury
a <5% in each group shown had missing data for each characteristic except for HDL cholesterol (missing for 5.5% of cases and 3.0% of controls)
bStratification variable used in selection of controls
cDefined as history of hospitalized myocardial infarction, coronary artery bypass grafting, angioplasty, or definite or probable angina.