Heuristic Medical Practice

Thomas L. Petty, M.D.

Professor of Medicine, 
University of Colorado

Chairman, National Lung Health Education Program (NLHEP)


National Lung Health Education Program
A collaborative project with



HealthOne Center
1850 High Street
Denver, CO 80218
Phone: 303 839 6755
Fax: 303 832 8137
e-mail: nlhep@aol.com

Heuristic Medical Practice

February 1996
PEP Pioneers
Second Wind
Torrance, California

Dear Friends,

     In this era of managed care, practice guidelines, and the proposed imperative of so-called “evidenced based medicine”, it is important to realize that we do not have enough established scientific facts to make many decisions that are required in the daily practice of medicine.  In fact, we can’t wait for controlled clinical trials to guide all of our treatment plans.  For example, there has never been a controlled clinical trial to test the effectiveness of a PAP smear in the diagnosis and care of early uterine cancer.  But no one would deny the effectiveness of this approach to early diagnosis and cure.  No one would want to do such a scientific trial, because the value is obvious and death rates from uterine cancer  are continually dropping, and are now at an all time low. 

     Heuristic comes for the Greek word heureskein, which means to discover and to learn.  Heuristic medicine is not based on hard core scientific evidence, but rather on principles, axioms, rules of thumb and, at times, “clinical imagination.”

     Even in the absence of scientific fact, physicians must and do decide.  Sometimes we challenge dogma.  For example, as a medical student, I was “taught” that patients with COPD cannot take oxygen, because the CO2 would always rise.  A further “established fact” was that exercise was bad for COPD, because it caused too much strain on the heart.  Both teachings were wrong, of course, as anecdotal experience suggested at first; later controlled clinical trials proved the value of oxygen and exercise in COPD.  These studies formed the scientific basis for pulmonary rehabilitation.  However, pulmonary rehabilitation began many years before the science that established its value..

     We are now challenging the dogma that there is no value in looking for or finding early lung cancer.  A growing number of uncontrolled studies now strongly indicate that this teaching was also incorrect.  Lung cancer is most common in patients with all stages of COPD.  Here is where we should start looking for early cases when lung cancer can be cured!  Why should lung cancer be ignored.  We don’t ignore other cancers which kill people and make them suffer.

     The medical profession has always assumed that it knows most of what needs to be known.  This misconception should lead to huge “humility factor”; it requires the practice of heuristic medicine.

I’ll be in touch next month.

Sincerely yours,

   Thomas Petty, MD

Last update:
9 April 2002