source("http://192.38.117.59/~linearpredictors/datafiles/readSurgery.R")

## Logistic regression models, setting reference level
surgery$blocking <- relevel(surgery$blocking, ref = 2)

model3 <- glm(complication ~ I(age/10):surgtype + surgtype + blocking - 1,
             family = binomial,
             data = surgery)
## the summary includes p-values for significance of terms
summary(model3) 

## OR for a 10 year difference in age
logOR <- c[6:8,"Estimate"]
se <- c[6:8,"Std. Error"]

logORconf <- cbind(logOR, logOR - 1.96*se, logOR + 1.96*se)
exp(logORconf)