Characteristics of cases and controls
| Characteristic | Cases, n = 1292 | Controls, n = 12 651 | p value* |
|---|---|---|---|
| Age, median (IQR) | 62 (54–72) | 62 (54–72) | 0.3 |
| Disease state,†no. (%) | |||
| Cancer | 227 (17.6) | 2183 (17.3) | 0.8 |
| Chronic obstructive pulmonary disease | 121 (9.4) | 1264 (10.0) | 0.5 |
| Congestive heart failure | 198 (15.3) | 1156 (9.1) | < 0.001 |
| Diabetes mellitus | 461 (35.7) | 3068 (24.3) | < 0.001 |
| HIV | 8 (0.6) | 34 (0.3) | 0.053 |
| Hypertension | 567 (43.9) | 4714 (37.3) | < 0.001 |
| Medications,‡no. (%) | |||
| Loop diuretics | 115 (8.9) | 654 (5.2) | < 0.001 |
| Nonsteroidal anti-inflammatory drugs | 15 (1.2) | 167 (1.3) | 0.8 |
| Renin–angiotensin-system blockers | 228 (17.7) | 1770 (14.0) | < 0.001 |
| Health care use,§median (IQR) | |||
| Billing codes, no. | 29 (11–62) | 39 (18–69) | 0.005 |
| Drugs, no. | 16 (4–31) | 11 (3–22) | < 0.001 |
| Physician visits, no. | 4 (2–8) | 4 (2–7) | 0.2 |
| Fluoroquinolone indications,§no. (%) | |||
| Joint or bone infection | 17 (1.3) | 143 (1.1) | 0.8 |
| Skin infection | 430 (33.3) | 4093 (32.4) | 0.5 |
| Tract infection | |||
| Genitourinary | 179 (13.9) | 1287 (10.2) | < 0.001 |
| Respiratory | 490 (37.9) | 5206 (41.2) | 0.03 |
| Gastrointestinal | 309 (23.9) | 3108 (24.6) | 0.6 |
Note: IQR = interquartile range.
↵* Calculated using χ2 test for categorical characteristics and Student t test for continuous characteristics.
↵† In the year before admission to hospital to maximize sensitivity.
↵‡ Current medication use at the time of hospital admission was used to best assess use at the index date.
↵§ In the 6 months before admission to hospital to reflect covariates during exposure ascertainment.