```Date: Sat, 23 Mar 1996 14:31:37 +0000 Reply-To: Miss LS Smoljanovic Sender: "SAS(r) Discussion" From: Miss LS Smoljanovic Subject: LOGISTIC PROCEDURE? Dear SAS-L members, my data set is described on following way: GP - a categorical variable (4 categories 1-2-3-4) Gender- (F or M) Agegroup- a categorical variable (5 categories 1-2-3-4-5). GP is a variable which has a value 1 in the case the subjects respond on the first mail, a value 2 if they did not respond on first one, but they responded on the second one, a value 3 if the did not repond on first and second but they did it on third and a vlue 4 if they did not respond. I would like to build logistic model with GP as a response variable and Gender and Agegroup as the explanatory variables on the following way: log(p1/1-p1)=beta0 + beta1 * x1 + beta2 * x2 (where p1 is the probability for positive respond on the first mail) log(p2/1-p1)=beta01+ beta1 * x1 + beta2 * x2 (where p2 is the probability for positive respond on the second mail ; so p2/1-p1 is the conditional probability for positive respond on the second mail given that some people already did positive respond on the first mail). . . . My question is : can I use the PROC LOGISTIC for testing the parallel lines assumption (assuming that my categorical variable GP is ordinal) i.e. the mocdel given by: g(Pr(Y<=i|x))=(1,x')gamma for i=1,...,k response levels of Y (response variable), x is the vector of explanatory variables, and gamma is a vector of unknown parameters consisting of an intercept gammai0 (SAS/STAT manual, pn 1090). Could you please suggest me something else (proc CATMOD //)? Thank you in advance. Lada ```

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