Table 1. Baseline characteristics.
| Characteristic | Covid-19 vaccinated, N = 911,381 |
Influenza vaccinated, N = 442,612 |
p- Value |
|---|---|---|---|
| Age, mean (SD) | 56.8 (18.3) | 56.5 (18.3) | <0.001 |
| Sex, female, n (%) | 504,072 (55.32) | 259,597 (58.65) | <0.001 |
| Race, white, n (%) | 788,451 (86.59) | 399,855 (90.41) | <0.001 |
| CCI, mean (SD) | 1.35 (2.19) | 1.57 (2.36) | <0.001 |
| Other comorbidities, n (%) | |||
| Atrial fibrillation | 68,263 (7.49) | 46,049 (10.40) | <0.001 |
| Hyperlipidemia | 301,709 (33.10) | 204,778 (46.27) | <0.001 |
| Hypertension | 286,147 (31.40) | 187,742 (42.42) | <0.001 |
| History of VTE | 32,463 (3.56) | 22,126 (5.00) | <0.001 |
| Site, n (%) | |||
| Medical College of Wisconsin | 119,371 (13.10) | 88,573 (20.01) | |
| Mayo Clinic Enterprise | 792,010 (86.90) | 354,039 (79.99) | |
Abbreviations: CCI, Charlson comorbidity index; SD, standard deviation; VTE, venous thromboembolism.