Table 1. Baseline Patient Characteristics.
| Characteristic | No. (%) | P value a | ||
|---|---|---|---|---|
| Syncope (n = 9223) | Syncope definite or likely (n = 5546) | Controls (n = 34 366) | ||
| Sex | ||||
| Female | 4710 (51.1) | 2809 (50.6) | 17 650 (51.4) | .63 |
| Male | 4513 (48.9) | 2737 (49.4) | 16 716 (48.6) | |
| Age, median (IQR) | 55 (35-72) | 52 (32-70) | 54 (35-70) | .09 |
| Rural residence | 1055 (11.4) | 640 (11.5) | 3978 (11.6) | .91 |
| ≥1 Hospitalization in prior year | 1267 (13.7) | 679 (12.2) | 6198 (18.0) | <.001 |
| ≥7 Physician visits in prior year | 6250 (67.8) | 3549 (64.0) | 24 953 (72.6) | <.001 |
| Charlson comorbidity score ≥2 | 1926 (20.9) | 1031 (18.6) | 7694 (22.4) | .002 |
| Selected comorbidities | ||||
| CVD | 2166 (23.5) | 1119 (20.2) | 7121 (20.7) | <.001 |
| Hypertension | 3244 (35.2) | 1768 (31.9) | 10 997 (32.0) | <.001 |
| Atrial fibrillation and flutter | 465 (5.0) | 227 (4.1) | 1768 (5.1) | .71 |
| Syncope | 322 (3.5) | 191 (3.4) | 353 (1.0) | <.001 |
| COPD | 1013 (11.0) | 546 (9.8) | 4666 (13.6) | <.001 |
| Psychiatric disorder | 2797 (30.3) | 1576 (28.4) | 11 381 (33.1) | <.0001 |
| Alcohol misuse | 283 (3.1) | 141 (2.5) | 1458 (4.2) | <.001 |
| Other substance misuse | 294 (3.2) | 160 (2.9) | 1790 (5.2) | <.001 |
| Prescription medications at baseline | ||||
| ≤1 | 5886 (63.8) | 3722 (67.1) | 21 228 (61.8) | <.001 |
| ≥2 | 3337 (36.2) | 1824 (32.9) | 13 138 (38.2) | |
| Antihypertensives | 3084 (33.4) | 1709 (30.8) | 10 369 (30.2) | <.001 |
| ACEi or ARB | 2051 (22.2) | 1123 (20.2) | 6366 (18.5) | <.001 |
| β Blockers | 1303 (14.1) | 674 (12.2) | 4315 (12.6) | <.001 |
| Calcium channel blockers | 971 (10.5) | 521 (9.4) | 3413 (9.9) | .09 |
| Diuretics | 1403 (15.2) | 782 (14.1) | 4609 (13.4) | <.001 |
| Antiseizure drugs | 512 (5.6) | 271 (4.9) | 1995 (5.8) | .37 |
| Benzodiazepines | 680 (7.4) | 330 (6.0) | 3137 (9.1) | <.001 |
| Opioids | 816 (8.8) | 448 (8.1) | 5022 (14.6) | <.001 |
| QTc-prolonging drugs | 1047 (11.4) | 567 (10.2) | 5401 (15.7) | <.001 |
| Driving history (prior 5 y) | ||||
| Full license (vs learners/novice) | 7760 (84.1) | 4660 (84.0) | 28 476 (82.9) | .008 |
| Active license | 8469 (91.8) | 5142 (92.7) | 31 210 (90.8) | .003 |
| Active insurance | 6169 (66.9) | 3701 (66.7) | 23 058 (67.1) | .71 |
| Insurance, median (IQR), d | 1132 (0-1825) | 1126 (0-1825) | 1043 (0-1825) | .04 |
| ≥1 Crash | 2348 (25.5) | 1408 (25.4) | 9281 (27.0) | .003 |
| ≥1 Contravention | 2417 (26.2) | 1491 (26.9) | 10 618 (30.9) | <.001 |
| Alcohol-related | 167 (1.8) | 107 (1.9) | 1041 (3.0) | <.001 |
| Speed-related | 1207 (13.1) | 742 (13.4) | 5084 (14.8) | <.001 |
| Distraction-related | 273 (3.0) | 171 (3.1) | 1155 (3.4) | .06 |
Abbreviations: ACEi, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; QTc, corrected QT interval on electrocardiogram.
a
P values for categorical data generated using a z test for 2 independent proportions, and for numeric data using the Mann-Whitney U test for 2 independent groups.