A data frame with 6805 observations on the following 7 variables.
center
a numeric code indicating in which of 67 centers the patient was treated.
age
of the patient.
begin
The month in which treatment began, with 1 representing January 1998.
end
The month in which observation terminated, either because of death or censoring.
The study ended in month 44 (August, 2000).
event
1, death, or 0, censoring.
time
the difference between end and begin.
disease
a factor with levels congen, (congenital); diabetes; hypert (hypertension); other; and renal.