Volume 3  Number 8  October 9, 2006
Second Opinions

"Medical Science": On Truth, Faith, and Belief

The music is not as good as it sounds.

Deems Taylor, music critic

Most of us are inclined to regard some discussions as mere philosophical prattle, questions such as "What is truth? "What is the nature of belief?" and ultimately "What is knowledge?" and "How do we Know Anything?"


People often say they "believe" in something, such as their favorite college football team or the stock market, meaning they predict that it will prove useful or successful in some sense. This is not the kind of belief under discussion, but rather I define that "to believe something" simply means to think that it is true.

"Truth" and The Scientific Method

The crucial question is: If knowledge is distinct from belief, how do we know a belief is true? Since the 17th Century, thinkers have continued to develop a systematic and powerful approach to the problem of truth. Called The Scientific Method, it uses various techniques for investigating phenomena and acquiring new knowledge and is based on observable, empirical, measurable evidence, and subject to laws of reasoning. Scientists propose predictions or hypotheses and design experiments to test these predictions for accuracy and verification. Theories addressing whole domains help form new hypotheses, but the tapestry of hypotheses is continuously being rewoven. Scientific knowledge regarded as Truth is always tentative, or provisional, constantly yielding to new experiments and information. Science is based on the premise that the process must be objective, and not subject to the bias of the scientist in interpreting results or changing them outright by lying.

The reader should understand that the scientific method can only be used to study questions susceptible to experiment or rational verification. This excludes many common beliefs and opinions, whether they deal with politics, religion (e.g. "intelligent design"), astrology, or dietary fads. Still, it must be admitted that claiming validity for the scientific method is itself a form of belief; itís special claim to superiority lies, among other things, in its practical success and the widespread acceptance of its approach to rationality. The founder of pragmatism, Charles Sanders Peirce, once wrote, "Truth is what the community of observers ultimately comes to believe."

Truth in the "Soft" and the "Hard" Sciences

Controversy continues to erupt over the concept of the "soft" sciences, including medicine, sociology, psychology, even economics-vs. the "hard" sciences, among which are mathematics, physics, and chemistry. The argument strongly suggests that the scientific method is weaker and subject to fewer rigors in the former than in the latter fields. Letís examine this idea in the case of medicine and in particular "medical science."

(Medical) Figures Donít Lie, but Liars Can Sure Figure

Risk: Absolute and Relative

When researchers, reporters, and others use data to compare two or more different groups, they may present their results in two very different and often confusing ways to emphasize a point of view. These relations may be expressed as either absolute or relative differences. An absolute difference is a subtraction; a relative difference is a ratio. More information.

To emphasize how easily people and even most physicians can be fooled, consider the following: Which drug would you rather take, one that reduces your risk of cancer by 50 percent, or another drug that only reduces your risk of cancer from two to one out of 100? Most people would choose the drug that reduces their risk of cancer by 50 percent, but in fact both these numbers refer to the same outcome. Theyíre just two different ways of looking at the same numbers. Without any qualification, both statements "reduced the risk by 50%" and "reduced the risk by 1 in a hundred" (1%) could be construed as representing either an absolute or relative difference. But note the difference in "feel" between 50% and 1%. Which figure sticks in your mind?

The headlines read, "Tamoxifen Cuts Breast Cancer Risk by 33% in Healthy Women!," yet it turns out, among all the women in a study who took Tamoxifen, less than 2% got breast cancer, and among those that took the placebo, less than 3% got breast cancer. The real difference was 1%. {"How to Lie With Statistics," Real Health Breakthroughs, Dr. William Campbell Douglass, 2004}

One of the main studies being cited in support of a new drug for advanced breast cancer, Herceptin©, saw 34 deaths in the control group (2.0% of the participants) and 23 deaths (1.4%) in the group treated with Herceptin. According to the authors, this translates into a 46% Relative Reduction in cancer deaths, (wrong calculation; should have been 2.0-1.4 divided by 2.0 or 30%) But the true absolute reduction in deaths is only 0.6% (2.0%-1.4%), almost certainly not statistically significant in this series. Is this a miracle drug? The number, of course, is pure marketing and statistical spin. As reported in the New Scientist magazine, one of the main cheerleaders for Herceptin is none other than Hortobagyi, a paid consultant of Genentech, who received somewhere between $10,000 and $100,000 from the drug company. He's one of the proponents who calls Herceptin a "cure."

Keep in mind that headlines promoting a drug will almost always refer to relative risk, "A breathtaking 40% reduction in risk!" -and this numerical shell game will be copied in the mainstream media, press, medical journals, even the FDA... Pharmaceutical companies, marketing reps, even some physicians anxious to publish and usually supported by commercial drug interests are constantly pushing and exaggerating the supposed benefits of their drugs while minimizing their risks.

Exposťs of the Clinical Literature

Odds ratios, as in "this horse is favored 4 to 1" and "P values", examples of relative differences, are a favorite ploy of drug advertisers and clinical researchers publishing in medical journals. In an important study, the significance of P values was compared with observational data in 260 abstracts of randomised controlled trials in PubMed, and concluded that "Significant results in abstracts are common but should generally be disbelieved."

Another study examined outcome reporting bias in 519 trials with 10,557 outcomes. The authors concluded that "Incomplete reporting of outcomes within published articles of randomised trials is common and is associated with statistical non-significance. The medical literature therefore represents a selective and biased subset of study outcomes..."

Random Thoughts about Truth in the "Modern" World

Modern life as mirrored in the media offers continuous stimulation in the form of entertainment, news, and advertising. Sadly, we are all drowning in "information," whether it is belief disguised as medical truth or opinion parading as received wisdom. Even "string theory," promoted as the holy grail of physics for over two decades is coming under attack. Public confusion reigns. Not a day passes when we donít hear about the dangers of HRT, antidepressants, Vioxx, and the importance of proper diet to protect us against cancer and heart attacks. The City of New York is even deciding whether to mandate the amount of trans fat allowed to be served in restaurants. Many beliefs edge into a form of snobbery when skeptics are ridiculed. We all want to be "right" and politically correct, even if, for example, Federal dietary guidelines change every few years or spectacular new medical treatments are proven to be dangerous.

Once we begin to acknowledge that life is all about uncertainty, we are still left with that slippery word, Truth, and its fashionable costumes of faith and belief. Ultimately, we are left to deal with faith, reason, and the actual basis of knowledge.

According to Gallup, 40% or 120 million of Americans take a literalist view of creation, believing that God created the universe, (either in millions of years or in 6 days), but place the big bang "2,500 years after the Babylonians and Sumerians learned to brew beer." Only 17% of us doubt that a personal God has authored the Bible, let alone created the earth and its 900,000 species of insects. As Sam Harris in The End of Faith (2004, W.W. Norton&Company, Inc.) also observes, "A survey of Hindus, Muslims, and Jews around the world would surely yield similar results revealing that we, as a species, have grown almost perfectly intoxicated by our myths." Can the human race, its very existence now imperiled by the clash of beliefs and civilizations, afford to drift entirely free of reason and evidence?

Martin F. Sturman, MD, FACP

Copyright 2006, Mathemedics, Inc.

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