Table 5 Vaccination and hazard ratios (HR) of influenza onset defined with ICD-10 codes only in Japanese subjects: time-dependent Cox hazard model

2013/2014 season vaccination

0.705 (0.670–0.741)

< 0.001

0.878 (0.849–0.908)

< 0.001

1.022 (0.963–1.085)

0.468

0.855 (0.814–0.899)

< 0.001

2012/2013 season vaccination

0.822 (0.779–0.868)

< 0.001

1.008 (0.975–1.042)

0.646

1.076 (1.013–1.142)

0.017

0.986 (0.932–1.042)

0.616

Age

1.223 (1.199–1.247)

< 0.001

0.936 (0.931–0.942)

< 0.001

0.775 (0.762–0.789)

< 0.001

0.985 (0.983–0.987)

< 0.001

Insured persons (vs Dependents)

–

–

–

–

1.146 (0.747–1.756)

0.533

1.356 (1.277–1.439)

< 0.001

Female (vs. Male)

0.931 (0.894–0.971)

0.001

0.984 (0.960–1.009)

0.220

0.820 (0.780–0.861)

< 0.001

1.232 (1.166–1.302)

< 0.001

Number of children aged 0 to 15 years in a family ^a

1.063 (1.035–1.092)

< 0.001

0.955 (0.938–0.971)

< 0.001

1.040 (1.007–1.074)

0.018

1.130 (1.107–1.153)

< 0.001

 High-risk condition

1.111 (1.062–1.163)

< 0.001

1.085 (1.051–1.120)

< 0.001

1.102 (1.021–1.190)

0.013

1.139 (1.084–1.198)

< 0.001

 During office hours (per visit)

1.014 (1.010–1.018)

< 0.001

1.007 (1.004–1.010)

< 0.001

1.019 (1.011–1.027)

< 0.001

1.016 (1.011–1.020)

< 0.001

 Outside office hours (per visit)

1.021 (0.995–1.048)

0.122

0.992 (0.974–1.011)

0.394

0.980 (0.948–1.014)

0.243

0.998 (0.978–1.019)

0.868

Emergency hospitalization

1.330 (0.715–2.475)

0.367

0.504 (0.252–1.008)

0.053

1.630 (0.924–2.876)

0.092

0.812 (0.504–1.308)

0.392

 Preceding onset of influenza in family members

4.671 (4.458–4.893)

< 0.001

2.261 (2.193–2.330)

< 0.001

1.906 (1.786–2.034)

< 0.001

4.530 (4.298–4.776)

< 0.001