Table 3 Effect of influenza vaccination on respiratory tract infections (RTIs) in general, with influenza positive swabs and/or 4-fold titre rise: multivariate regression analysis for correlated data (GEE)
Outcome | RTI in general (n = 202) | RTI with positive swabs for influenza (n = 202) | RTI with pos swabs and/or 4-fold titre rise for influenza (n = 150) | ||||||
|---|---|---|---|---|---|---|---|---|---|
Parameter1 | OR estimate | 95%CI | OR estimate | 95%CI | OR estimate | 95%CI | |||
Lower limit | Upper limit | Lower limit | Upper limit | Lower limit | Upper limit | ||||
Vaccine†2 when GP is 30 years old | 0.35 | 0.13 | 0.96 | 0.1 | 0.01 | 0.75 | 0.13 | 0.02 | 0.98 |
Vaccine† when GP is 50 years old | 1.79 | 0.80 | 4.00 | 1.41 | 0.35 | 5.76 | 0.82 | 0.21 | 3.25 |
Co-variates | |||||||||
Year 2002/2003 | 0.98 | 0.49 | 1.96 | 0.42 | 0.13 | 1.42 | 0.52 | 0.18 | 1.53 |
Age‡3 | 0.49 | 0.17 | 1.43 | 0.58 | 0.17 | 1.96 | 0.37 | 0.09 | 1.53 |
Gender† | 0.60 | 0.33 | 1.10 | 0.96 | 0.29 | 3.23 | 0.99 | 0.33 | 2.94 |
Basic immunity (natural logarithm of titre1)‡4 | 1.18 | 0.91 | 1.55 | 0.57 | 0.37 | 0.89 | 0.57 | 0.38 | 0.86 |
Mean number of patient contacts/day‡5 | 1.17 | 0.50 | 2.76 | 1.77 | 0.47 | 6.69 | 3.13 | 0.69 | 14.11 |
Mean number of contacts with influenza patients/day‡6 | 0.67 | 0.44 | 1.00 | 0.33 | 0.10 | 1.12 | 0.39 | 0.13 | 1.16 |
Family members with influenza† | 1.88 | 0.97 | 3.64 | 9.24 | 2.91 | 29.40 | 3.62 | 1.20 | 10.89 |
Colleagues with influenza† | 1.10 | 0.60 | 2.01 | 0.60 | 0.19 | 1.84 | 0.71 | 0.25 | 2.04 |
Having young children < 7 years of age† | 2.00 | 0.95 | 4.24 | 1.37 | 0.42 | 4.52 | 1.04 | 0.30 | 3.67 |
Working in Child and family preventive medicine facility† | 0.76 | 0.31 | 1.87 | 1.76 | 0.52 | 5.92 | 1.15 | 0.28 | 4.66 |
† dichotomous yes(1), no(0) | |||||||||
‡ continuous | |||||||||
1Intercept = | 0.96 | -1.63 | 3.54 | 0.68 | -2.24 | 3.61 | 2.44 | -1.41 | 6.28 |
2 Crude OR vaccine = | 0.97 | 0.56 | 1.67 | 0.55 | 0.24 | 1.28 | 0.35 | 0.15 | 0.79 |
3 OR for difference of 20 years | |||||||||
4 OR for a difference of 1 in natural logarithm of titre1 | |||||||||
5 OR for a difference of 20 patients | |||||||||
6 OR for a difference of 2 influenza patients | |||||||||