The Sashelp.BMT (bone marrow transplant) data set is used to illustrate survival analysis methods. At the time of transplant, each patient is classified into one of three risk categories: ALL (acute lymphoblastic leukemia), AML-Low Risk (acute myelocytic leukemia, low risk), and AML-High Risk. The endpoint of interest is the disease-free survival time, which is the time in days to death, relapse, or the end of the study. In this data set, the variable Group represents the patient’s risk category, the variable T represents the disease-free survival time, and the variable Status is the censoring indicator such that the value 1 indicates an event time and the value 0 indicates a censored time. The following steps display information about the Sashelp.BMT data set and create Figure B.2:

title 'Bone Marrow Transplant Data';
proc contents data=sashelp.BMT varnum;
   ods select position;
run;

title 'The First Five Observations Out of 137';
proc print data=sashelp.BMT(obs=5);
run;

title 'The Risk Group Variable';
proc freq data=sashelp.BMT;
   tables group;
run;