Hurdle model for longitudinal data?

[Sandahl]

Hello,

I am modeling hospital visits (from a household survey where zero visits was an option and accounts for about 70%).

This is a longitudinal study (3 time points).

A zero inflated Poisson did not fit the data well.

Is there a way to calculate a two part model for longitudinal data in SAS?

Thank yo

[SteveDenham]

I think NLMIXED may be your only option, and even that will be messy.  I would start by doing a very careful search of the SAS-L archives (https://listserv.uga.edu/cgi-bin/wa?A0=SAS-L) for posts by David Cassell on the topic of zero-inflated and hurdle models using NLMIXED.

Steve Denham