Table 4. Determinants of breakthrough infections among vaccinated patients over a 6-month period using univariate analysis and multivariable logistic regression models.
| Univariate analysis | Multivariable logistic regression models | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Model 1 i | Model 2 ii | ||||||||
| Categorical variables | % | P | adj. OR | 95%CI | P | adj. OR | 95%CI | P | |
| Sex | |||||||||
| Female1 | 6.81 | ||||||||
| Male | 2.15 | 0.16 | 0.35 | 0.05–1.63 | 0.21 | 0.30 | 0.04–1.37 | 0.15 | |
| Smoking | |||||||||
| No1 | 3.57 | ||||||||
| Yes | 5.80 | 0.48 | |||||||
| Alcohol consumption | |||||||||
| No1 | 5.09 | ||||||||
| Yes | 0.00 | 0.60 | |||||||
| Blood type & Rhesus factor | |||||||||
| A-1 | 0.00 | ||||||||
| A+ | 3.92 | ||||||||
| AB+ | 10.0 | ||||||||
| B- | 0.00 | ||||||||
| B+ | 11.5 | ||||||||
| O- | 0.00 | ||||||||
| O+ | 3.33 | 0.59 | |||||||
| Chronic disease | |||||||||
| No1 | 2.91 | ||||||||
| Yes | 6.41 | 0.29 | 2.48 | 0.55–13.1 | 0.25 | ||||
| Vaccine type ¶ | |||||||||
| Pfizer-BioNTech (BNT162b2)1 | 2.29 | ||||||||
| AstraZeneca | 10.0 | 0.04 | 5.35 | 1.22–27.9 | 0.03 | 4.75 | 1.11–24.2 | 0.04 | |
| Side effects after the first shot | |||||||||
| No1 | 4.00 | ||||||||
| Yes | 4.58 | 1.00 | |||||||
| Continuous variables | Breakthrough infection | No breakthrough infection | P | adj. OR | 95%CI | P | adj. OR | 95%CI | P |
| Age (years) | 51.4 | 52.2 | 0.86 | ||||||
| Body Mass Index (kg/m 2 ) | 28.1 | 27.1 | 0.74 | ||||||
¶Determinants of breakthrough infections were predicted using univariate (t-test and the chi-squared test for continuous and categorical variables, respectively) and multivariable analysis (logistic regression models). iThe variables tested by univariate analysis that had a P value (P) < 0.40 were included in Model 1 (multivariable logistic regression analysis). iiIn Model 2, a backward logistic regression model was created including only complete cases. 1Reference group. *During the study period. ¶Individuals who had received a Sputnik V vaccination were removed from the analysis because of their low total number.