Below are some sources for prevalences and pretest probabilities. There is
one caution for all of this that has been referred to in the recent
messages, but has not been dealt with head on. The use of population
prevalences for pretest probabilities is highly problematic for the simple
reason that the general population is not the same as the population that
presents itself to any individual clinician. Each clinician must develop a
good idea of how their patient population differs from the general
population or the population that a particular prevalence or pretest
probability was taken from. In addition, as has been mentioned,
characteristics of the individual patient, such as smoking, sex, age, etc.,
will place the patient in yet a different population. Even highly
subjective estimates of how these things will affect the pretest probability
may be better than blindly using published population prevalences. Ideally,
keeping a running tab of disease occurrences in ones own practice could be
used, provided there is enough followup to catch missed and false diagnoses.
It would seem to be helpful in judging the effects of subjective estimates
to play around with the available published nomograms for converting pretest
probabilities by way of likelihood ratios into post-test probabilities (see
http://cebm.jr2.ox.ac.uk/docs/2x2table.html).
The following message regarding sources for pretest probabilities appeared
earlier on the Society for Medical Decision Making list:
From: Dolan, James [SMTP:[log in to unmask]]
Sent: Wednesday, January 27, 1999 9:32 AM
To: [log in to unmask]
Subject: Re: data base for Bayesian clinical decision making
A new edition of the book "Diagnostic strategies for common medical
problems" (previously edited by Panzer, Black and Griner - I think the new
editors are Panzer, Black and Bordley) Published by the ACP will be
available this spring. It will contain > 50 chapters summarizing current
disease prevalences and test operating characteristics. If you would like
more information, I suggest you contact Ed Black at [log in to unmask]
Other places you should look at include the Centre for Evidence based
medicine at oxford: http://cebm.jr2.ox.ac.uk/ , a publication called
Bandolier (also from Oxford) at
http://www.jr2.ox.ac.uk/Bandolier/index.html, and probably also the McMaster
web site: http://hiru.mcmaster.ca/
Hope this helps.
Regards,
Jim Dolan
James G. Dolan, M.D.
Director General Medicine Unit
Highland Hospital
1000 South Ave
Rochester, NY 14620
phone: 716-341-6771
fax: 716-341-8305
I followed up on the Panzer et al. book and got the following reply:
The new edition of Diagnostic Strategies will be ready sometime in April.
It is again being published by ACP-ASIM in Philadelphia and you can contact
them at any time (215-351-2400, Books Division) for a summary of the book,
pricing, etc. The editors for this edition are Black, Bordely, Tape, and
Panzer. The book is as described, about 51 clinical problems with sections
in each chapter on pretest probability and test operating characteristics.
Ed Black
Well, that's my two cents worth, or should I say tuppence.
David L. Doggett, Ph.D., Medical Research Analyst
Health Technology Assessment and Information Service
ECRI, a non-profit health services research organization
5200 Butler Pike, Plymouth Meeting, PA 19462 USA
(610) 825-6000 ext. 5509, FAX (610) 834-1275
[log in to unmask]
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|