Summary

Using Generalized Linear Models, you have fit a series of complementary log-log regression models for interval-censored survival data. While there is some support for choosing treatment A, achieving a statistically significant result may require a larger study. However, there are some further avenues to explore with the existing data.

• It may be worthwhile to refit the model with interaction effects, particularly between Period and Treatment group.
• The existing model assumes, for a given individual, that the probability of recurrence in the first period is independent of the probability of recurrence in the second period. In fact, you may very reasonably assume that these observations are correlated, in which case fitting a model using the Generalized Estimating Equations procedure would be appropriate.