Multivariable estimate of JE risk ratio for vaccine coverage year, controlling for seasonal periodicity using Poisson regression.

RR = risk ratio;aBased on Wald chi-square test;bRisk Ratio;cReference.dβ-value.Akaike information criterion = 317.398, Adjusted Pseudo-R2 = 0.278. cos12 and sin12 models annual periodicity; cos6 and sin6 models biannual periodicity. Pseudo- R2 is based on 1 minus the deviance ratio between the full model vs. the Intercept only model adjusting for the number of explanatory terms in a model (1 – (Full model DEV/Intercept only model DEV) * ((n-1)/(n-k-1))), where n is the sample size and k is the number of explanatory terms.