> library(foreign)
> ds <- read.dta("c:/chd.dta")
> attach(ds)
> logpyrs <- log(pyrs)
> model1 <- glm(chd ~ smoke + offset(logpyrs), family=poisson(link="log"))
> summary(model1)
Call:
glm(formula = chd ~ smoke + offset(logpyrs), family = poisson(link = "log"))
Deviance Residuals:
Min 1Q Median 3Q Max
-3.9742 -1.0629 0.0985 1.6875 4.7543
Coefficients:
Estimate Std. Error z value Pr(>|z|)
(Intercept) -4.799334 0.088520 -54.217 < 2e-16 ***
smoke 0.031754 0.005624 5.646 1.64e-08 ***
---
Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
(Dispersion parameter for poisson family taken to be 1)
Null deviance: 119.061 on 15 degrees of freedom
Residual deviance: 89.382 on 14 degrees of freedom
AIC: 163.69
Number of Fisher Scoring iterations: 5
Loglinear (Poisson) Regression Model of CHD on Smoking , Behavior Type and Blood Pressure
> model2 <- glm(chd ~ smoke + behavior + bp + offset(logpyrs),
+ family=poisson(link="log"))
> summary(model2)
Call:
glm(formula = chd ~ smoke + behavior + bp + offset(logpyrs),
family = poisson(link = "log"))
Deviance Residuals:
Min 1Q Median 3Q Max
-1.8038 -0.7615 -0.2933 1.0110 1.8821
Coefficients:
Estimate Std. Error z value Pr(>|z|)
(Intercept) -5.420153 0.130813 -41.434 < 2e-16 ***
smoke 0.027344 0.005614 4.871 1.11e-06 ***
behavior 0.752555 0.136202 5.525 3.29e-08 ***
bp 0.753376 0.129240 5.829 5.57e-09 ***
---
Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
(Dispersion parameter for poisson family taken to be 1)
Null deviance: 119.061 on 15 degrees of freedom
Residual deviance: 21.240 on 12 degrees of freedom
AIC: 99.546
Number of Fisher Scoring iterations: 4