I'm working with time-to-event data that is right-censored for two different groups. I have administrative data that gives me information on the outcomes and associated covariates. There are a couple of categorical variables that definitely have an effect on the outcome, but they are not in the administrative data. However, I have some survey results that give me estimates on the distributions of the categorical variables for the two groups.
For example, say the two groups are Group 1 and Group 2, and I have a covariate $W$ with "success" probabilities as
$W | \text{Group 1} \sim \text{Bernoulli(0.9)}$
and
$W | \text{Group 2} \sim \text{Bernoulli(0.3)}$
Is there a way to incorporate this survey data into a "proportional hazards"-like model? I'm pretty sure there's something related to Bayesian statistics here, but I'm not sure what I should be looking for here. If there's another approach I'd be all ears!