48 rats were injected with a carcinogen, and then
randomized to either drug or placebo. The number of tumors ranges
from 0 to 13; all rats were censored at 6 months after randomization.
Usage
rats2
Format
rat:
id
trt:
treatment,(1=drug, 0=control)
observation:
within rat
start:
entry time
stop:
exit time
status:
event status, 1=tumor, 0=censored
Source
MH Gail, TJ Santner, and CC Brown (1980),
An analysis of comparative carcinogenesis experiments based on
multiple times to tumor.
Biometrics36, 255–266.