I have multiple cox models (with one variable static in all models) and am trying to extract the coefficient for that variable. 

In all models the coefficient is indexed as follows: for example in model1 it is model1[[8]][1] ; for model2 it is model2[[8]][1] etc. I attempted to create a for loop but R as shown below but its not working. 

Could someone help me why I am getting an error when running the following code

```
for (i in 1:5) {
coef[i] <- exp(summary(model[i])[[8]][1])
}

```

I get the following error "object 'model' not found".

Many thanks in advance

A