Sashelp Data Sets

Bone Marrow Transplant Data

The Sashelp.BMT (bone marrow transplant) data set is used to illustrate survival analysis methods (Klein and Moeschberger 1997). 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.5:

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

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

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

Figure B.5: Bone Marrow Transplant Data

Bone Marrow Transplant Data

Variables in Creation Order
# Variable Type Len Label
1 Group Char 13 Disease Group
2 T Num 8 Disease-Free Survival Time
3 Status Num 8 Event Indictor: 1=Event 0=Censored

The First Five Observations Out of 137

Obs Group T Status
1 ALL 2081 0
2 ALL 1602 0
3 ALL 1496 0
4 ALL 1462 0
5 ALL 1433 0

The Risk Group Variable

Disease Group
Group Frequency Percent Cumulative
ALL 38 27.74 38 27.74
AML-High Risk 45 32.85 83 60.58
AML-Low Risk 54 39.42 137 100.00