Variations in Physician Practice: The Role of Uncertainty

Prologue: Nothing more underscores the reality that medical care represents a melding of art and science than the wide variation in the use and cost of that care. One of the factors that leads to practice variations is uncertainty in the minds of doctors about how to approach a particular medical problem. David Eddy, who holds a medical degree from the University of Virginia and a doctor of philosophy degree in applied mathematics from Stanford University, has made a professional career of reducing uncertainty in medical practice and helping doctors find their way to the most efficacious treatments for patients. Eddy operates at the intersection of math and medicine, applying probability theory to the uncertainty of approaches to care. Although his pursuits have not always been appreciated by the profession —many of his conclusions cut against the grain of conventional medical judgment—Eddy has been awarded the Manchester Prize by the Operations Research Society of America, the most prestigious honor that this organization of applied mathematicians bestows. Eddy was recognized for a book he authored entitled, Screening for Cancer: Theory, Analysis and Design . The essence of the book was a study undertaken by the American Cancer Society to determine how often a doctor should give women a pap smear. For forty years, the society has promoted the annual pap smear as a cancer detection treatment. Factoring in all of the relevant data and subjecting it to his mathmatical microscope, Eddy determined that the most sensible frequency for administering this test is every three years. The cancer society changed its recommendations accordingly, provoking a storm of controversy within some medical quarters. The American College of Obstetrics and Gynecology took particular exception to the recommended three-year frequency, but the cancer society did not waver from its new standard. Eddy is a member of the Institute of Medicine of the National Academy of Sciences and is a member of the World Health Organization Expert Advisory Panel on Cancer. Eddy is now developing a third-party payer process of setting reimbursement policies for medical procedures.