Table 4.
Models of logistic regression for predictors of SARS-CoV-2 seropositivity.
| Model 1 (n = 2919) |
Model 2 (n = 1647) |
|||
|---|---|---|---|---|
| Adjusted odds ratio (aOR) (95% CI;LL-UL) | p-value | Adjusted odds ratio (aOR) (95% CI;LL-UL) | p-value | |
| Gender | ||||
| Male | Ref. | Ref. | ||
| Female | 0.995(0.830–1.194) | 0.960 | 1.073(0.815–1.413) | 0.615 |
| Age (years) | ||||
| >15 | Ref. | Ref. | ||
| 15–29 | 1.211(0.918–1.597) | 0.175 | 2.947(0.547–15.890) | 0.209 |
| 30–39 | 0.985(0.741–1.310) | 0.918 | 2.211(0.411–11.882) | 0.355 |
| 40–59 | 1.041(0.802–1.351) | 0.764 | 2.524(0.473–13.463) | 0.278 |
| 60+ | 1.099(0.788–1.533) | 0.577 | 3.194(0.572–17.831) | 0.186 |
| Residence | ||||
| Urban | 0.946(0.796–1.124) | 0.524 | 0.799(0.603–1.060) | 0.120 |
| Rural | Ref. | Ref. | ||
| Crowding Index | ||||
| < 1 | Ref. | Ref. | ||
| 1+ | 1.229 (1.041–1.451)a | 0.015 | 1.355(1.086–1.690)a | 0.007 |
| Smoking status | ||||
| No | 1.817(1.407–2.346)a | 0.000 | 2.052 (1.525–2.763)a | 0.000 |
| Yes | Ref. | Ref. | ||
| Blood group | ||||
| A | 1.231(1.016–1.493)a | 0.034 | 1.065(0.813–1.394) | 0.648 |
| B | 1.167(0.950–1.433) | 0.142 | 1.153(0.869–1.529) | 0.324 |
| AB | 1.058(0.787–1.423) | 0.707 | 0.933(0.622–1.399) | 0.737 |
| O | Ref. | Ref. | ||
| BMI | ||||
| Normal weight | Ref. | Ref. | ||
| Underweight | 0.710(0.376–1.341) | 0.291 | 0.783(0.120–5.083) | 0.848 |
| Overweight/obese | 1.193(0.987–1.441) | 0.068 | 1.384(1.059–1.808)a | 0.019 |
| History of COVID-19 infection | ||||
| Never | Ref. | Ref. | ||
| Yes | 2.997(2.176–4.127)a | 0.000 | 3.350(2.307–4.863)a | 0.000 |
| Contact with COVID-19 patientb | — | |||
| No | Ref. | |||
| Yes | 0.876(0.728–1.053) | 0.160 | ||
| Vaccination status against COVID-19 | ||||
| Not vaccinated | Ref. | Ref. | ||
| Vaccinated | 4.349(2.798–6.759)a | 0.000 | 5.979(3.655–9.779)a | 0.000 |
| Reported COVID-19 symptoms in past 6 months | ||||
| Fever | ||||
| No | Ref. | Ref. | ||
| Yes | 1.269(1.033–1.560)a | 0.023 | 1.544(1.154–2.065)a | 0.003 |
| Cough | ||||
| No | Ref. | Ref. | ||
| Yes | 0.947(0.782–1.146) | 0.573 | 0.824(0.635–1.070) | 0.147 |
| Dyspnea | ||||
| No | Ref. | Ref. | ||
| Yes | 0.916(0.713–1.178) | 0.494 | 0.915(0.654–1.281) | 0.605 |
| Anosmia and/or Ageusia | ||||
| No | Ref. | Ref. | ||
| Yes | 3.453(2.661–4.481)a | 0.000 | 3.306(2.355–4.640)a | 0.000 |
| Rhinorrhea | ||||
| No | Ref. | Ref. | ||
| Yes | 0.998(0.832–1.196) | 0.982 | 1.126(0.882–1.437) | 0.342 |
| Fatigue | ||||
| No | Ref. | Ref. | ||
| Yes | 1.089(0.783–1.515) | 0.612 | 0.853(0.556–1.309) | 0.466 |
| Myalgia/arthralgia | ||||
| No | Ref. | Ref. | ||
| Yes | 0.886(0.631–1.242) | 0.482 | 0.961(0.628–1.469) | 0.854 |
| Eye redness | ||||
| No | Ref. | Ref. | ||
| Yes | 0.812(0.586–1.125) | 0.210 | 0.704(0.460–1.077) | 0.105 |
| Sleep problems | ||||
| No | Ref. | Ref. | ||
| Yes | 1.010(0.758–1.347) | 0.945 | 1.174(0.819–1.685) | 0.382 |
| Occupational risks (n = 1647) | ||||
| Occupation | ||||
| Non- HCWs | Ref. | |||
| HCWs | 1.760(1.301–2.381)a | 0.000 | ||
| Having roommates at work | ||||
| No | Ref. | |||
| Yes | 1.047(0.772–1.420) | 0.767 | ||
| Environmental disinfection | ||||
| No | 1.058(0.828–1.353) | 0.652 | ||
| Yes | Ref. | |||
| Rooms are well-ventilated | ||||
| No | Ref. | |||
| Yes | 1.308(0.921–1.858) | 0.134 | ||
| Use of air conditioner at work | ||||
| No | 1.235(0.912–1.672) | 0.172 | ||
| Yes | Ref. | |||
| Number of days working online/week | ||||
| 1–3 | Ref. | |||
| 4–5 | 1.398(0.988–1.978) | 0.058 | ||
| 6–7 | 1.301(0.957–1.769) | 0.094 | ||
HCWs, healthcare workers.
Model 1; The overall model is statistically significant, χ2 = 351.066, p = 0.00, Nagelkerke R2 = 0.153, Percentage accuracy = 62.5%.
Model 2; The overall model is statistically significant, χ2 = 309.163, p = 0.00, Nagelkerke R2 = 0.229, Percentage accuracy = 67.6%.
a
Significant results p< 0.05.
b
Contact with COVID patient was omitted from model 2 as it was highly correlated with the occupation.