Is why we do what we do reason enough to do it?

I live on an organic farm. Not that I'm a huge believer in organic farming, but my wife is. We have cows, chickens, dogs, cats, and more species on the way. In the past decade I have learned about animals, organic farming, and organic solutions around the farm.

If you visit our farm, you will notice partially filled baggies of water and a penny hanging in front of every door of our house. This is an organic method of keeping flies out of the house. Scientific explanations for this method hinge on the fly’s dislike of water, and the fact that their eyes split images into thousands of parts, so one little baggie of water looks like an ocean. Makes sense-too bad it doesn’t work. Fortunately, it has the hidden benefit of making a nice house look like a mobile home, so we are less likely to be robbed.

It strikes me that medicine and organic farming are much alike in this respect. We do a lot of things because that is the way someone told us to do it. We develop elaborate scientific explanations for why it works, and then we continue to do it based on anecdotal support, even when national consensus says it is not the best way of doing things. Since I joined Nightshift Radiology, I have been exposed to the wide variations in practice patterns across the U.S.

If you look up vertigo in the ACR appropriateness criteria, the highest rated test (if you need one at all) is an MRI with and without contrast. CT is not quite so high. What is being done around the country is a little bit of everything. I cover some hospitals where coming to the ER “dizzy” will get you a CT head with CTA head/neck in a heartbeat. At some hospitals with 24/7 MRI coverage, you will have an MRI/MRA of the head and neck before you sit down in the ER. I was taught all you need in the ER is a noncontrast head CT to exclude blood and mass effect, a shot of Vistaril, and an appointment with a neurologist. How can there be so much variation in approach to one problem?

Organic farming techniques go back thousands of years, while “modern” farming only starts with the industrial revolution. Organic farmers will proselytize at length about the life-affirming qualities of their methods and the horrors induced by chemicals in farming. They are oblivious to the fact that since the development of modern farming techniques our lifespan and our food productivity have increased dramatically. They long to go back to the good old days when people died at 50. And they can give you compost piles of anecdotal evidence to support their favored methods.

When I talk to ER docs, it seems to me the most powerful influences on decision-making are how they were trained to do something originally and their most recent “oh my god” case. A diagnosis of pulmonary embolism used to require much more clinical judgment, and the diagnosis was often difficult. These days ER docs are ordering chest CTA at the drop of a hat. The threshold for the test changes every time they are surprised by a positive result with low pretest probability. They’re like organic farmers: If it worked once, it must be the way to go.

What is the best way to do this medicine stuff? The government wants and thinks it can all be standardized, which may happen, up to a point. But our personal experiences influence our judgment, which is the crux of medical decision-making. Applying ACR appropriateness criteria and the numerous published clinical scales may bring some national conformity. But what we really need is an absolute rule, similar to the one governing me and organic farming: “If mamma ain’t happy, ain’t no one happy.”