age
| The mid-point of the 10 year age-group for the doctors. |
smoke
| An indicator of whether the doctors smoked (1) or not (0). |
n
| The number of person-years in the category. |
y
| The number of deaths attributed to coronary artery disease. |
ns
|
The number of smoker years in the category (smoke*n ).
|
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, N.E. (1985) Cohort Analysis in Epidemiology. In A Celebration of Statistics A.C. Atkinson and S.E. Fienberg (editors), 109-143. Springer-Verlag.
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.