August 15, 2008

Prescribing a dose of healthy skepticism

Headlines declare wine is good for your health. So is a small bit of dark chocolate. Then, they say it's not. One day coffee is bad for you and the next it's good. We're bombarded with health messages daily from companies selling things, advocacy groups promoting their agendas and journalists trying to sift through it all. Who are you to believe? Unless you have a degree in epidemiology, it's very difficult to discern the valuable information from all the garbage. In his new book, "The Healthy Skeptic," journalist Robert Davis gives readers some quick tips to become better consumers of health care information.

"A healthy skeptic carefully and critically evaluates each piece of advice taking into account not only its source but the science behind it," Davis writes.
Davis has 20 years' experience as a health and medical journalist, as well as a Ph.D. and M.P.H. in health policy and public health. He teaches at Emory's school of public health. In the book, Davis uses common examples of over-hyping that upon inspection often prove incomplete or even misleading, such as misguided dieting advice and the total prevention promises of lowering cholesterol and wearing sunscreen. He also offers several examples of how overzealous health promoters have led consumers astray, such as Oprah's on-air full body CT-Scan; Katie Couric's promotion of colonoscopies before the recommended age of 50; and the unproven but nearly messianic messages about cancer screening.

Davis gives health promoters the benefit of the doubt that their errors result from having to snag consumers' attention while competing with thousands of messages bombarding them daily.
"To convey complex scientific information in this environment, health promoters may resort to oversimplifying or sensationalizing," Davis writes "They may not necessarily lie to us, but like anyone else trying to sell something, they don't always give us the full truth, either. Instead, what we may get, even from individuals and organizations with the most altruistic of motives, is hype, half-truths and spin." Davis offers eight questions to help readers assess the science behind a health message before drawing conclusions. I doubt the average consumer will apply his evaluation techniques, but certainly anyone who buys the book would find them helpful. And this should be required reading for health and medical journalists.

The Healthy Skeptic's eight key questions:

What kind of study is behind the research? Is it a gold standard randomized clinical trial or is it an observational population study? The latter can only show strong associations and never definitively prove a risk or benefit.

How big is the effect shown in the study? The larger the effect the more believable it is.

Could the findings be a fluke? In other words, is it statistically significant?

Who was studied? Do the study subjects closely resemble the population for which the the conclusions are being extrapolated?

Is there a good explanation? Is there a believable biological explanation for the study's findings?

Who paid for the research? Could the funding source have influenced the researchers, either consciously or subconsciously?

Was it peer reviewed? Did it appear in a respected journal that required other scientists to critique it first?

How does it square with other studies? Individual studies are pieces of a larger puzzle and the entire puzzle must be examined before conclusions can be drawn.


This post originally published August 15, 2008 by Sally Arnquist on The Health Care Blog.