Format
A data frame with 20 observations on the following 3 variables.
number
- number of colonic polyps at 12 months.
treat
- treatment arms of the trail, a factor with
levels
placebo
and drug
. age
- the age of the patient.
Source
F. M. Giardiello, S. R. Hamilton, A. J. Krush, S. Piantadosi, L. M. Hylind,
P. Celano, S. V. Booker, C. R. Robinson and G. J. A. Offerhaus (1993),
Treatment of colonic and rectal adenomas with sulindac
in familial adenomatous polyposis. New England Journal of Medicine,
328(18), 1313--1316. S. Piantadosi (1997), Clinical Trials: A Methodologic Perspective.
John Wiley \& Sons, New York.