This morning, KQED public radio’s Forum program aired a piece about tooth flossing: Episode airs August 3, 2016 at 9:00 AM
The tag line reads: “Since 1979, the federal government has recommended flossing daily to help prevent gum disease and cavities. But according to a new report by the Associated Press, there’s little scientific evidence to support that advice. We’ll drill down into the data, and we want to hear from you: Will the news affect your oral hygiene routine?”
The problem with this discussion hinges on the difference between statistical and individual results. I, personally, am a good example of this. I have two gaps between molars that have enlarged as I’ve gotten older. When I chew meat little bits lodge in these gaps and the gum there becomes inflamed within 24 hours if I don’t remove the debris with floss (or a toothpick). For me, flossing is critical. My individual experience may not have any perceptible effect on statistical results but it is critical to my personal health. No “scientific” (read statistical) study can tell me what will benefit me. I’ve had several occasions when doctors tell me a behavior or treatment is not worth doing because there are no scientific studies that support it. Unfortunately, it is not possible to determine whether you or I fall within the large number of individuals who populate the high point on the statistical curve or are part of the long tails on either side of the statistical norm.
When dealing with personal health, paying attention to statistical probability tells us only how likely it is that a medication or treatment will help us but tells us nothing about how any one person will respond. The bottom line, on flossing or any other medical recommendation, is to look for a personal solution. The fact that a treatment doesn’t work for 99 out of 100 people does not prove it will not work for you or me.
Attention to medical research results, research results in any field for that matter, should not be limited to reports of statistically significant outcomes. The gap between what is statistically likely or probable and what actually happens in any given situation is unpredictable. Research that uncovers rare phenomenon is just as important as that which shows us the commonplace.
The medical profession, the government and the media can actually harm individual health by focusing public trust on statistically probable to the exclusion of exploratory research outcomes. Doctors hesitate to try unusual treatments when more common solutions fail. The FDA limits access to drugs that are effective for small numbers of people and encourages everyone to consume foods that may be harmful to some. The media often touts studies that just barely cross the threshold of statical credibility but excite an uninformed audience.
I applaud KQED for opening up this discussion about federal recommendations and personal practice. Let’s go further and address how to interpret the discoveries, meanings and messages of scientific research.