Demographic and clinical characteristics of ventricular arrhythmia cases and matched controls in an inception cohort of new users of antibiotics across all databases (1-stage pooling)
| Characteristic | Group; no. (%) of patients* | p value | |
|---|---|---|---|
| Cases† n = 12 874 | Controls n = 1 240 431 | ||
| Age, yr, mean ± SD | 63.5 ± 15.3 | 63.6 ± 15.4 | Matching factor |
| Age group, yr | |||
| < 60 | 4210 (32.7) | 405 621 (32.7) | |
| 60–79 | 7106 (55.2) | 678 516 (54.7) | |
| ≥ 80 | 1558 (12.1) | 156 294 (12.6) | |
| Sex | Matching factor | ||
| Male | 8561 (66.5) | 824 887 (66.5) | |
| Female | 4313 (33.5) | 415 544 (33.5) | |
| Well-known risk factors for ventricular arrhythmia | |||
| Atrial fibrillation/flutter | 2332 (18.1) | 61 844 (5.0) | < 0.001 |
| Cardiomyopathy | 1097 (8.5) | 10 887 (0.9) | < 0.001 |
| Cerebrovascular event | 1539 (12.0) | 81 444 (6.6) | < 0.001 |
| Coronary artery disease | 5919 (46.0) | 229 811 (18.5) | < 0.001 |
| Electrolyte imbalance | 1100 (8.5) | 57 663 (4.6) | < 0.001 |
| Heart failure | 2913 (22.6) | 54 114 (4.4) | < 0.001 |
| Hypertension | 10 254 (79.6) | 730 389 (58.9) | < 0.001 |
| Peripheral arterial disease | 626 (4.9) | 26 970 (2.2) | < 0.001 |
| Prior use of anti-arrhythmic drugs | 1009 (7.8) | 13 865 (1.1) | < 0.001 |
| Concomitant use‡ of medications known to induce hypokalemia | 4661 (36.2) | 211 284 (17.0) | < 0.001 |
| Concomitant use‡ of QT-interval–prolonging drugs§ | 2089 (16.2) | 75 177 (6.1) | < 0.001 |
| Potential risk factors for ventricular arrhythmia¶ | |||
| Alcohol abuse | 343 (2.7) | 12 157 (1.0) | < 0.001 |
| Chronic liver disease | 683 (5.3) | 43 325 (3.5) | < 0.001 |
| Chronic respiratory disease | 5310 (41.2) | 390 364 (31.5) | < 0.001 |
| Conduction disorders | 1146 (8.9) | 27 911 (2.3) | 0.001 |
| Congenital heart disease | 151 (1.2) | 2968 (0.2) | < 0.001 |
| Diabetes mellitus | 2395 (18.6) | 140 208 (11.3) | < 0.001 |
| Hyperthyroidism | 300 (2.3) | 16 195 (1.3) | < 0.001 |
| Hypothyroidism | 1033 (8.0) | 68 233 (5.5) | < 0.001 |
| Acute and chronic renal failure | 802 (6.2) | 23 324 (1.9) | < 0.001 |
| Lipid metabolism disorders | 5906 (45.9) | 351 428 (28.3) | < 0.001 |
| Obesity | 1223 (9.5) | 71 835 (5.8) | < 0.001 |
| Other cardiac arrhythmias** | 1394 (10.8) | 34 920 (2.8) | < 0.001 |
| Cardiac valve disorders | 1012 (7.9) | 28 970 (2.3) | < 0.001 |
Note: SD = standard deviation.
↵* Unless stated otherwise.
↵† Current users of both azithromycin and other antibiotics were not included in the analysis.
↵‡ Within 3 mo before index date.
↵§ Use of drugs with established torsadogenic risk according to CredibleMeds list.27
↵¶ Information on smoking status was partly available only in 2 databases and therefore was not included in the final multivariate models.
↵** Except for atrial fibrillation/flutter, conduction disorders, QT-interval prolongation, ventricular arrhythmia and sudden cardiac death.