University of Waterloo O
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403575 /

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Waterloo, Ontario, Canada

Faculty of Engineering
Department of Management Sciences

September 10, 1969

Professor Joshua Lederberg,
Department of Genetics,

Stanford University Medical Center,
Stanford, California, 94305

Dear Professor Lederberg:

Thank you for your letter of August 7, 1969
which I finally received last week. (I changed faculty
positions in late July and my mail was delayed in Boston).
I agree wholeheartedly with your concern about untreated
(clinically) syphilis, self-treatment procedures, and low
percentage reporting of cases by private physicians.

Unfortunately I have not carried the studies
any further. Therefore, I have not estimated the cost-
effectiveness of the items listed in your letter. How-
ever, I would like to comment on one point that you made.
You said that there is no obvious way of knowing how
many pre-maritals are positive. Doesn't a state form
have to be completed by the physician concerning each
premarital? If so, it would be unlikely that he would
deliberately incorrectly report a positive as negative;
certainly less likely than simply not reporting a positive
reaction at some time other than a pre-marital (in this
latter situation I agree that the reporting rate is pro-
bably quite low).

As I believe I mentioned in my paper, a more
complete model would necessitate some form of simulation.
However, simulation without meaningful parameter values
(one of the main purposes of our study was to indicate
data needs) would be of questionable utility. I am
hoping eventually to have one or two graduate students

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vile benefit bust serssamg of
Professor J. Lederberg -2- 10 September 1969

work in this area (naturally, conditional upon some
sort of research grant).

If I can be of any further assistance, please
do not hesitate to contact me.

Sincerely,

Gaurerd A. diluer

Edward A. Silver,
Associate Professor.

EAS/pgu