Re-thinking the Annual Physical

Please note: the following refers to routine physicals and screening tests in healthy, asymptomatic adults. It does not apply to people who have been diagnosed with diseases, who have any kind of symptoms or signs, or who are at particularly high risk of certain specific diseases. Throughout most of human history, people have consulted doctors

Virtual Colonoscopy Can Be Hazardous to Your Health

The US Preventive Services Task Force (USPSTF) recommends that everyone aged 50-75 be screened for colon cancer with any one of three options: colonoscopy every 10 years, flexible sigmoidoscopy every 5 years, or fecal occult blood testing (FOBT) every year. Conventional colonoscopy is considered the “gold standard” since it allows for direct detection and biopsy


Dr. H. Gilbert Welch has written a new book Over-diagnosed: Making People Sick in the Pursuit of Health, with co-authors Lisa Schwartz and Steven Woloshin.  It identifies a serious problem, debunks medical misconceptions and contains words of wisdom. We are healthier, but we are increasingly being told we are sick. We are labeled with diagnoses that

Questioning Colonoscopy

Everybody knows that colonoscopy is the best test to screen for colorectal cancer and that colonoscopies save lives. Everybody may be wrong. Colonoscopy is increasingly viewed as the gold standard for colorectal cancer screening, but its reputation is not based on solid evidence. In reality,  it is not yet known for certain whether colonoscopy can

Screening Tests – Cumulative Incidence of False Positives

It’s easy to think of medical tests as black and white. If the test is positive, you have the disease; if it’s negative, you don’t. Even good clinicians sometimes fall into that trap. Based on the pre-test probability of the disease, a positive test result only increases the probability by a variable amount. An example:

A Skeptical Look at Screening Tests

I’m an equal opportunity skeptic. I’m skeptical about alternative medicine, pseudoscience, and quackery; but I apply the same standards of skepticism to conventional medicine. I don’t write about conventional medicine so much, because I don’t need to. Science itself is inherently skeptical and scientific medicine is self-criticizing and self-correcting. When better evidence comes along, medical

Ultrasound Screening, Fish Oil, and Ear Candles: Sometimes Ignorance is Bliss

I never thought I’d be promoting ignorance!  I’ve always thought the more information, the better; but there are exceptions. I’m going to explain something that is very counterintuitive and grates against every fiber of our truth-seeking skeptical brains. The ad shouts, “Tests That Can Save Your Life… Stroke is America’s third leading killer… Half of