Q. Several years ago, I began hearing the term "evidence-based medicine" being used a lot. However, it seems to be used in very different ways by different people. What does this term really mean?

A. Evidence-based medicine sounds like a good idea. Who wouldn't want medicine based on evidence? However, the term is sometimes used inconsistently. Evidence-based medicine can make important contributions to medicine, but at times the term may have connotations — and may even be used by some doctors as if to suggest that practitioners of other medical paradigms don't have sufficient evidence for what they do. What qualifies as "evidence" can be highly subjective.

Evidence-based medicine attempts to apply scientific method to medicine based largely on statistical evidence. This can be a good thing, but may fail to include other important criteria. One commonly cited definition of evidence-based medicine is "the conscientious, explicit and judicious use of current best evidence" in medical decisions. But what's "conscientious," "judicious" and "best"?

Questions about what constitutes "evidence," who decides what constitutes it, and what their standards are, often seem to go unanswered. Even some who promote evidence-based medicine don't adequately define "evidence" on their websites. The closest one proponent comes to defining it is vague: "clinically relevant research, often from the basic sciences of medicine." (What's "relevant" and "often"?)

The Holy Grail of evidence-based medicine is the randomized, double-blind, placebo-controlled trial. Elevating this to Holy Grail status may inadvertently downgrade other types of evidence to a lower order of value. For example, we have ample historical and anthropological evidence that certain practices from Chinese medicine worked for thousands of years, but no "studies" were conducted prior to the modern Western conventional medical paradigm. Some followers of evidence-based medicine tend to demote the value of the collective wisdom of some of the world's great healing traditions — including some knowledge passed down to us over millennia by countless generations.

Evidence-based medicine may also tend to discount clinical evidence. Every day, doctors weigh empirical evidence in clinical experience, draw conclusions, and witness powerful transformations in people's lives that often defy studies. An oversimplistic evidence-based medicine mentality can reduce the mysteries of medicine to a cookie-cutter approach and overlook the deep nature of the healing process. For some, it may be about statistical abstractions, not about you as a unique individual, what you are experiencing, and what you need.

Perhaps the most glaring shortcoming of evidence-based medicine: randomized, double-blind, placebo-controlled trials are prohibitively expensive. Frequently the only ones who can afford them are pharmaceutical giants with obvious conflicts of interest, seeking to establish evidence for products they stand to profit from — hardly the place to begin if you want unbiased scientific inquiry.

The bottom line: Medicine is both a science and an art. Caring for patients includes the use of information derived from both the rigors of scientific inquiry and clinical evidence, as well as from medical traditions that have stood the test of time.

Laurie Steelsmith is a naturopathic physician and licensed acupuncturist in Honolulu, as well as author of the book "Natural Choices for Women's Health," published by Random House. You can reach her and read her past columns at www.DrSteelsmith.com. This column is for information only. Consult your health provider for medical advice.