Following on this post from last fall, check out this Scientific American excerpt of the new book, Demand Better! Revive Our Broken Health Care System (Second River Healthcare Press, March 2011) by Sanjaya Kumar, chief medical officer at Quantros, and David B. Nash, dean of the Jefferson School of Population Health at Thomas Jefferson University:

Most of us are confident that the quality of our healthcare is the finest, the most technologically sophisticated and the most scientifically advanced in the world. And for good reason–thousands of clinical research studies are published every year that indicate such findings. Hospitals advertise the latest, most dazzling techniques to peer into the human body and perform amazing lifesaving surgeries with the aid of high-tech devices. There is no question that modern medical practices are remarkable, often effective and occasionally miraculous.

But there is a wrinkle in our confidence. We believe that the vast majority of what physicians do is backed by solid science. Their diagnostic and treatment decisions must reflect the latest and best research. Their clinical judgment must certainly be well beyond any reasonable doubt. To seriously question these assumptions would seem jaundiced and cynical.

But we must question them because these beliefs are based more on faith than on facts for at least three reasons, each of which we will explore in detail in this section. Only a fraction of what physicians do is based on solid evidence from Grade-A randomized, controlled trials; the rest is based instead on weak or no evidence and on subjective judgment. When scientific consensus exists on which clinical practices work effectively, physicians only sporadically follow that evidence correctly.

Medical decision-making itself is fraught with inherent subjectivity, some of it necessary and beneficial to patients, and some of it flawed and potentially dangerous. For these reasons, millions of Americans receive medications and treatments that have no proven clinical benefit, and millions fail to get care that is proven to be effective. Quality and safety suffer, and waste flourishes.

At first blush, this may seem shocking, but it really provides a great incentive for the consumer of health care services and products to be as fully informed as possible about various treatment alternatives.

The human body is an incredibly complex organism. That we can predict and control outcomes relating to such complexity in even a fraction of cases is a remarkable achievement.

The approach we need to take is to embrace that complexity and randomness, educate ourselves as best we can on the risks that certain behaviors and habits have in regard to affecting bad health outcomes, and then lead our lives in a way that deals with those risks in a manner that is acceptable to each individual.

However, the reality is that neither we – nor our doctors – control the outcome of many of our health care decisions. We can make choices based on the best available information. But life is still largely a roll of the dice.