breslow  Smoking Deaths Among Doctors 
 Description
The 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. 
Usage
breslow
Format
This data frame contains the following columns:
- 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).
Source
The data were obtained from
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.
References
Davison, A.C. and Hinkley, D.V. (1997) Bootstrap Methods and Their Application. Cambridge University Press.
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.
    Copyright (©) 1999–2012 R Foundation for Statistical Computing.
Licensed under the GNU General Public License.