FILENAME goptions URL "http://192.38.117.59/~linearpredictors/datafiles/goptions.sas";
%include goptions;

FILENAME url URL "http://192.38.117.59/~linearpredictors/datafiles/readPbc3.sas";
%include url;

/* create new variables relating to normal range: 0-17.1 */

DATA pbc3; SET pbc3;
   logbili=log(bili); 
   lbilicent=logbili-log(17.1);
   bililarge=(bili>=17.1);
   logbilipos=bililarge*lbilicent;
RUN;

/* fit models from table */

PROC PHREG;
model followup*status(0)=bililarge logbilipos;
RUN;

PROC PHREG;
model followup*status(0)=bililarge logbilipos lbilicent;
RUN;

PROC PHREG;
model followup*status(0)=lbilicent;
RUN;

/* LR tests are found by subtraction */