Table 2.
Logistic regression analysis of variables associated with occupational SARS-CoV-2 infection among hospital workers.
| Variable | Univariable Analysis | Multivariable Analysis | ||||
|---|---|---|---|---|---|---|
| Crude OR | (95% CI) | p Value | Adjusted OR | (95% CI) | p Value | |
| Demographic | ||||||
| Age (year) | 1.01 | (1–1.02) | 0.216 | 1.01 | (1–1.02) | 0.053 |
| Male gender | 1.26 | (0.98–1.63) | 0.068 | 1.11 | (0.83–1.48) | 0.480 |
| The highest education attainment | <0.001 | <0.001 | ||||
| Primary or secondary school (reference) | ||||||
| Associate’s | 0.64 | (0.47–0.86) | 0.004 | 0.76 | (0.54–1.06) | 0.106 |
| Bachelor’s | 0.34 | (0.25–0.45) | <0.001 | 0.44 | (0.32–0.61) | <0.001 |
| Master’s | 0.19 | (0.1–0.34) | <0.001 | 0.31 | (0.17–0.58) | <0.001 |
| Doctoral | 0.18 | (0.07–0.43) | <0.001 | 0.36 | (0.14–0.92) | 0.033 |
| Role of worker: Healthcare personnel | 0.92 | (0.67–1.27) | 0.620 | |||
| Exposure characteristics | ||||||
| Infected person was not wearing a mask/N95 respirator during exposure | 2.86 | (2.15–3.81) | <0.001 | 1.45 | (1–2.1) | 0.048 |
| Distance of exposure less than 1 m | 1.83 | (1.31–2.57) | <0.001 | 1.4 | (0.97–2) | 0.069 |
| Duration of exposure more than 15 min | 4.53 | (3.35–6.11) | <0.001 | 2.51 | (1.81–3.48) | <0.001 |
| Exposed hospital worker not wearing a mask/N95 respirator during exposure | 4.48 | (3.49–5.77) | <0.001 | 2.54 | (1.72–3.76) | <0.001 |
| Exposed hospital worker not wearing face shield or goggles during exposure | 2.72 | (1.93–3.83) | <0.001 | 1.25 | (0.78–1.98) | 0.353 |
| Infected person was undergoing aerosol-generating procedures | 0.156 | 0.001 | ||||
| No (reference) | ||||||
| Yes; exposed HCP was wearing N95 respirator/PAPR and face shield | 0.61 | (0.15–2.48) | 0.486 | 1.28 | (0.29–5.66) | 0.748 |
| Yes; exposed HCP was not wearing N95 respirator/PAPR and face shield | 1.53 | (0.96–2.44) | 0.075 | 2.86 | (1.64–5) | <0.001 |
| Exposed hospital worker had direct contact with aerodigestive secretion of the infected person | 4.41 | (3.19–6.11) | <0.001 | 1.48 | (1.02–2.15) | 0.038 |
| Symptoms of exposed hospital worker | ||||||
| Fever or other COVID-19-related symptoms | 5.44 | (4.26–6.95) | <0.001 | 4.9 | (3.78–6.34) | <0.001 |
| COVID-19 vaccination status | ||||||
| Potency of COVID-19 vaccines * | <0.001 | <0.001 | ||||
| None (reference) | ||||||
| Low-potency vaccines | 0.31 | (0.19–0.51) | <0.001 | 0.31 | (0.18–0.54) | <0.001 |
| Moderate-potency vaccines | 0.19 | (0.11–0.32) | <0.001 | 0.16 | (0.09–0.3) | <0.001 |
| High-potency vaccines | 0.04 | (0.01–0.28) | 0.001 | 0.05 | (0.01–0.41) | 0.005 |
| The interval between the last dose of COVID-19 vaccines and exposure (day) | (1–1.01) | 0.402 | ||||
| Previous COVID-19 infection: Yes | 1.1 | (0.34–3.51) | 0.878 | |||
* Adapted from Thai COVID-19 Vaccination Guidelines for a Booster Shot, Ministry of Public Health, December 2021.