Table 3.
Risks of systemic events (N=2080) after the second dose of COVID-19 vaccination with BNT162b2 according to selected variables among healthcare workers in a large university hospital, Milan, Italy
| Variable | Systemic events | RR crude | RR adjusted* | |||
|---|---|---|---|---|---|---|
| N | % | RR | 95% CI | RR | 95% CI | |
| Gender | ||||||
| Male | 524 | 50.0 | 1.00 | Reference | 1.00 | Reference |
| Female | 1556 | 59.6 | 1.19 | 1.11-1.28 | 1.14 | 1.06-1.24 |
| Age category (years) | ||||||
| <35 | 816 | 63.8 | 1.00 | Reference | 1.00 | Reference |
| 35-44 | 395 | 60.4 | 0.95 | 0.88-1.02 | 0.93 | 0.85-1.01 |
| 45-54 | 508 | 55.8 | 0.87 | 0.81-0.94 | 0.86 | 0.79-0.93 |
| 55+ | 361 | 44.2 | 0.69 | 0.64-0.76 | 0.69 | 0.62-0.76 |
| P-trend | <0.001 | <0.001 | ||||
| Occupation | ||||||
| Physicians | 376 | 51.0 | 1.00 | Reference | 1.00 | Reference |
| Residents | 198 | 60.6 | 1.19 | 1.06-1.33 | 1.01 | 0.87-1.14 |
| Nurses | 580 | 57.7 | 1.13 | 1.04-1.24 | 1.08 | 0.98-1.18 |
| Healthcare assistants | 120 | 53.8 | 1.05 | 0.92-1.21 | 1.08 | 0.92-1.25 |
| Health technitians | 364 | 61.6 | 1.21 | 1.10-1.33 | 1.12 | 1.02-1.24 |
| Clerical workers, technicians | 324 | 55.4 | 1.09 | 0.98-1.20 | 1.14 | 1.03-1.27 |
| Students | 118 | 61.8 | 1.21 | 1.06-1.38 | 1.00 | 0.86-1.15 |
| BMI category (kg/m2) | ||||||
| <20 | 405 | 61.9 | 1.00 | Reference | 1.00 | Reference |
| 20-24.99 | 992 | 57.4 | 0.93 | 0.86-1.00 | 0.99 | 0.92-1.07 |
| 25-29.99 | 423 | 53.3 | 0.86 | 0.79-0.94 | 0.99 | 0.90-1.08 |
| 30+ | 144 | 52.2 | 0.84 | 0.74-0.96 | 0.94 | 0.82-1.07 |
| P-trend | <0.001 | 0.61 | ||||
| Cigarette smoking | ||||||
| Never | 1200 | 58.7 | 1.00 | Reference | 1.00 | Reference |
| Former | 332 | 55.3 | 0.94 | 0.87-1.02 | 1.01 | 0.93-1.09 |
| Current | 443 | 52.7 | 0.90 | 0.83-0.97 | 0.90 | 0.84-0.97 |
| P-trend | 0.003 | 0.02 | ||||
| History of allergy | ||||||
| No | 1569 | 55.1 | 1.00 | Reference | 1.00 | Reference |
| Yes | 465 | 62.5 | 1.13 | 1.06-1.21 | 1.13 | 1.05-1.20 |
| Previous SARS-CoV-2 infection | ||||||
| No | 1841 | 57.0 | 1.00 | Reference | 1.00 | Reference |
| ≤180 days before | 145 | 50.5 | 0.89 | 0.79-1.00 | 0.86 | 0.76-0.98 |
| >180 days before | 94 | 64.8 | 1.14 | 1.00-1.29 | 1.16 | 1.01-1.32 |
| P-trend | 0.71 | 0.63 | ||||
| ACEI therapy | ||||||
| No | 2002 | 56.8 | 1.00 | Reference | 1.00 | Reference |
| Yes | 32 | 50.8 | 0.89 | 0.70-1.14 | 1.02 | 0.80-1.30 |
| ARB therapy | ||||||
| No | 1999 | 56.9 | 1.00 | Reference | 1.00 | Reference |
| Yes | 35 | 44.9 | 0.79 | 0.62-1.01 | 0.97 | 0.75-1.25 |
Abbreviations: ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin II receptor blocker; BMI, body mass index; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2