Table 6.
Multiple logistic regression analysis of variables for diphtheria immunitya
| Characteristics | OR (95%CI) | 95%CI | p-Valueb |
|---|---|---|---|
| Age groups | |||
| 0-5 | 1.5 | 0.7-2.6 | 0.09 |
| 6-10 | 1.6 | 0.6-2.5 | <0.001 |
| 11-20 | 1.8 | 0.8-3.3 | <0.001 |
| 21-30 | 2.7 | 1.5-5.0 | <0.001 |
| 31-40 | 2.5 | 1.5-4.9 | <0.001 |
| 41-50 | 1.8 | 1.6-4.0 | <0.001 |
| 51-60 | 1.6 | 1.2-3.1 | <0.01 |
| >61 (Ref) | - | - | - |
| Ethnicity | |||
| Kinh (Ref) | - | - | - |
| Ba Na | 0.9 | 0.6-1.3 | 0.62 |
| So Dang | 1.3 | 0.9-1.8 | 0.13 |
| Others | 1.3 | 0.9-1.7 | 0.09 |
| Residence | |||
| Rural (Ref) | - | - | - |
| Urban | 0.8 | 0.6-1.3 | 0.06 |
| Occupation | |||
| Farmer/worker (Ref) | - | - | - |
| Pupil/Student | 0.7 | 0.3-1.1 | 0.3 |
| Employer | 0.6 | 0.4-1.2 | 0.5 |
| Self-employed/unemployment | 0.9 | 0.5-1.4 | 0.4 |
| History of diphtheria vaccination during last 10 years | |||
| Yes | - | - | - |
| No | 4.7 | 3.8-6.5 | <0.0001 |
| Unknown | 3.8 | 2.6-5.7 | <0.0001 |
a
Susceptibility: IgG antibody titre against diphtheria toxin < 0.01 IU/mL
b
Logistic regression analysis, main effects model. All variables are listed which attained a statistical significance of p < 0.05