breslow
data frame has 10 rows and 5 columns.
In 1961 Doll and Hill sent out a questionnaire to all men on the British
Medical Register enquiring about their smoking habits. Almost 70% of
such men replied. Death certificates were obtained for medical practitioners
and causes of death were assigned on the basis of these certificates. The
breslow
data set contains the person-years of observations and deaths from
coronary artery disease accumulated during the first ten years of the study.
breslow
age
smoke
n
y
ns
smoke*n
).
Doll, R. and Hill, A.B. (1966) Mortality of British doctors in relation to smoking: Observations on coronary thrombosis. National Cancer Institute Monograph, 19, 205-268.