05-06-2014 05:03 AM
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.
05-08-2014 05:05 PM
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.
05-09-2014 08:36 AM
05-09-2014 09:47 AM
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.