I'm using the RDMSMisClass model for a disease scenario where an animal's infection status is sometimes not assessed (making it 'uncertain'). In the input file, I have coded 'N's and 'P's to denote positive and negative infection states and 'u's for the uncertain state.
When I look at the design data fields generated, I see a "stratum" field consisting of Ns and Ps, and two dummy variable columns (labeled N and P) that contain 0s and 1s. If I run a model with a stratum effect (~stratum), the estimates labeled with N and P are the reverse of what I get if I use the dummy variables (~N or ~P) to specify the model. What am I missing here?
With ~P
- Code: Select all
> S.P$results$real
estimate
S sP gHE c1 a0 t1 0.3184553
S sN gHE c1 a0 t1 0.4859625
With ~N
- Code: Select all
> S.N$results$real
estimate
S sP gHE c1 a0 t1 0.3184554
S sN gHE c1 a0 t1 0.4859623
With ~stratum
- Code: Select all
> S.strat$results$real
estimate
S sP gHE c1 a0 t1 0.4654214
S sN gHE c1 a0 t1 0.3199899
I'm also wondering how to decipher (or to dictate) whether the prevalence term in this model (Omega) is giving me the proportion of the population in state P or in state N.
Thanks for any help!
Brittany