Nonlinear inverse prediction

[namodelali]

Hello,

For research purposes, I would like to know the method SAS uses to perform an inverse prediction of confidence interval in the context of a nonlinear model. For exemple for a 4 parameter logistic model(dose response model),  whith which method SAS obtains by inverse prediction,  the confidence interval of a concentration knowing the corresponding response value? I could not find that information in the SAS documentation.

Thank you.

[StatDave]

Inverse confidence limits in the context of a binary response model (logistic or probit) can be done using the INVERSECL option in PROC PROBIT.  The method used is described in the "Details: Inverse Confidence Limits" section of the PROBIT documentation.

[SteveDenham]

Following on to 's comment:  There are good methods if you use PROBIT.  If you have fit a 4 parameter model in NLIN or NLMIXED, I am afraid that you will have to write DATA step code or PROC IML code to get what you need.

Steve Denham

[namodelali]

Thank you!  That helps to find that the methods are there for PROBIT. Since what I am interested in, are growth curves like the 4 parameter model, i will probably write a code with PROC IML to find my inverse confidence interval.

[namodelali]

Thank you.