Patients in this trial were drawn from two separate clinics. Repeat

the analysis for Problem 13.1.1, allowing the effects of treatment (and,

possibly, time) to depend on clinic.

(a) Is the effect of treatment the same in the two clinics? Present results to

support your conclusion.

(b) Find a parsimonious model that describes the effects of clinic,

treatment, and time, on the log odds that respiratory status is classified as

good. For the model selected, give a clear interpretation of the estimated

regression parameters for the final model selected.

13.1.4 For the final model selected in Problem 13.1.3, construct a table of

the estimated probabilities that respiratory status is classified as good as a

function of both time and treatment group (and, possibly, clinic). What do

you conclude from this table?