Primary Biliary Cirrhosis (PBC) Data

Well-known data set from Appendix D of Fleming and Harrington (1991) taken from Terry Therneau's website. 
We have copied the data set and here is SAS code to read in the data and run a standard Cox regression.
 Note that in the SAS code we eliminate cases past 312 and recode status=1 (liver transplant) to be
 status=0 (alive, i.e., censored). There are only 276 complete cases when running a Cox regression 
with all covariates. From Terry Therneau's website, the variables in the data set are
id       = case number
futime   = number of days between registration and the earlier of death,
           transplantion, or study analysis time in July, 1986
status   = 0=alive, 1=liver transplant, 2=dead
drug     = 1= D-penicillamine, 2=placebo
age      = age in days
sex      = 0=male, 1=female
ascites  = presence of ascites: 0=no 1=yes
hepato   = presence of hepatomegaly 0=no 1=yes
spiders  = presence of spiders 0=no 1=yes
edema    = presence of edema 0=no edema and no diuretic therapy for edema;
          .5 = edema present without diuretics, or edema resolved by diuretics;
           1 = edema despite diuretic therapy
bili     = serum bilirubin in mg/dl
chol     = serum cholesterol in mg/dl
albumin  = albumin in gm/dl
copper   = urine copper in ug/day
alk_phos = alkaline phosphatase in U/liter
sgot     = SGOT in U/ml
trig     = triglicerides in mg/dl
platelet = platelets per cubic ml/1000
protime  = prothrombin time in seconds
stage    = histologic stage of disease