################################################################ ### Example 2.11 - Modelling differences in SMRs in relation ### ### to differences in exposures ### ################################################################ ### Fitting a model to estimate the relative risk associated with ### air pollution summary(glm(Y ~ offset(log(E)) + X1, family="poisson", data=data)) ### Fitting a model to estimate the relative risk associated with ### air pollution using a Quasi-Poisson approach summary(glm(Y ~ offset(log(E)) + X1, family="quasipoisson", data=data)) ### Fitting a Poisson GLM with air pollution and deprivation summary(glm(Y ~ offset(log(E)) + X1 + X2, family="poisson", data=data)) ### Fitting a Quasi-Poisson GLM with air pollution and deprivation summary(glm(Y ~ offset(log(E)) + X1 + X2, family="quasipoisson", data=data)) ### Perform tests between the deviances of two models # Test 1: Effect on Quasi-Poisson models with and without deprivation anova(glm(Y ~ offset(log(E))+X1,family="quasipoisson",data=data), # Model 1 glm(Y ~ offset(log(E))+X1+X2,family="quasipoisson",data=data), # Model2 test="Chisq") # Chi-Squared test # Test 2: Effect on Quasi-Poisson models with and without air pollution anova(glm(Y ~ offset(log(E))+X1+X2,family="quasipoisson",data=data), # Model 1 glm(Y ~ offset(log(E))+X2,family="quasipoisson",data=data), # Model 2 test="Chisq") # Chi-Squared test