Table 1. Selected Characteristics of Case and Control Patients, Sunnybrook Hospital, Toronto, Canada, June 2010 to May 2012.
| Incident Cases | Controls | P value | |
| (N = 127) | (N = 1940) | ||
| N (%) | N (%) | ||
| Age, median (IQR), y | 72.0 (57.6–79.8) | 67.3 (53.2–79.2) | 0.14 |
| Male sex | 69 (54.3) | 989 (51.0) | 0.52 |
| Admissions | |||
| 1 | 76 (59.8) | 1494 (77.0) | <0.001 |
| 2 | 30 (23.6) | 302 (15.6) | <0.001 |
| ≥3 | 21 (16.5) | 144 (7.4) | <0.001 |
| ICU stay | 64 (50.4) | 379 (19.5) | <0.001 |
| Disease pressurea | |||
| median per 100 patient-days (IQR) | 20.0 (0.0–50.0) | 0.0 (0.0–50.0) | 0.12 |
| Days of antibiotic exposure, | |||
| median per 100 patient-days (IQR) | 46.2 (25.0–76.0) | 0.0 (0.0–60.0) | <0.001 |
| Antibiotic exposure | |||
| Total | 110 (86.6) | 961 (49.5) | <0.001 |
| Penicillins | 38 (29.9) | 220 (11.3) | <0.001 |
| Broad-spectrum | 29 (22.8) | 191 (9.8) | <0.001 |
| Narrow-spectrum | 12 (9.4) | 43 (2.2) | <0.001 |
| Cephalosporins/carbapenems | 91 (71.7) | 642 (33.1) | <0.001 |
| 1st & 2nd generation | 44 (34.6) | 388 (20.0) | <0.001 |
| 3rd & 4th generation | 59 (46.5) | 326 (16.8) | <0.001 |
| Carbapenems | 11 (8.7) | 41 (2.1) | <0.001 |
| Fluoroquinolones | 49 (38.6) | 381 (19.6) | <0.001 |
| IV vancomycin | 28 (22.0) | 107 (5.5) | <0.001 |
| Other exposures | |||
| Antacids (PPIs and H2 inhibitors) | 96 (75.6) | 1268 (65.4) | 0.024 |
| Laxatives | 91 (71.7) | 1187 (61.2) | 0.024 |
| Feeding tube | 53 (41.7) | 263 (13.6) | <0.001 |
Abbreviations: PPI, proton pump inhibitor; ICU, intensive care unit; IQR, interquartile range.
a
equal to the number of patients diagnosed with CDI in the same ward as a given patient each day.
b
2 degree of freedom Pearson's Chi-square test.