08 9386 7080 Dr J.R. Johnstone

0408 990 936 7 Bruce St,

ray@iinet.com.au Nedlands 6009

www.iinet.com.au/~ray Western Australia

 

 

Professor R.D. De Vaux,

Bronfman Science Center,

Williams College,

Williamstown, MA01267

Dear Professor De Veaux,

In your book "Intro Stats", you say (p126) "Ironically, the proof that smoking indeed is the cause of many cancers came from experiments conducted following the principles of experimental design and analysis that Fisher himself developed – and that we’ll see in Chapter 13." Chapter 13 is about controlled intervention trials. Seven such trials have been conducted to determine the association between smoking and health, with a hundred thousand test and control subjects followed for seven years – Whitehall, MRFIT, Goteburg, Finnish Businessmen, Oslo, WHO collaborative and North Karelia. (References are available on my website.) The results of all are uniform, forthright and unequivocal: they show no association between smoking and life expectancy, deaths from cancer or deaths from any other cause.

The "proof" that smoking causes cancer and other diseases comes from trials of the kind Fisher had condemned – uncontrolled, nonrandomised, nonintervention trials such as the British Doctors and American Cancer Society studies: it is these which have been used to calculate the number of deaths supposedly caused by smoking.

For real irony read the words of A.B. Hill, a principal author of the British Doctors study. On p250 of his Principles of Medical Statistics" (1971) he uses the words "inferior" and "second-best" to describe such work. But perhaps that is more hypocrisy than irony.

This is surely a unique episode. So far as I am aware, nowhere in medical science are the results of controlled intervention trials rejected in favour of uncontrolled non-intervention trials. But it is more than unique. It is scandalous.

It is clear that Fisher loved the science of statistics. He would have been appalled to witness a generation of statisticians degrade that science.

Yours sincerely

Ray Johnstone