A Study a Day Keeps the Doctor Away

Is hard evidence the best medicine for patients and the health care system?

| Utne Reader September / October 2007

As much as we'd like to believe that medicine is exact, it often seems unpredictable, more a method of trial and error than precision. The care you receive can depend on what doctor you see, what health plan you use--and even something as arbitrary as your ZIP code.

If you live in Wyoming, for instance, you're five times more likely to have back surgery than if you lived in Hawaii. In Nebraska, you're more than twice as likely to have a knee replaced than in New Jersey. And if you're a woman diagnosed with breast cancer in South Dakota, you're nearly seven times more likely to have a mastectomy than if you lived in Vermont.

Well-informed patients should know about these geographic discrepancies, reported in a 2006 analysis by Dartmouth Medical School researchers, if only to grasp the tremendous variation in treatments recommended by American doctors. And, as patients are asked to take on more and more responsibility when it comes to making (and paying for) health care choices, it's important they understand that there's often little or no scientific evidence they will be better off undergoing expensive, invasive treatments. In fact, sometimes these cures do more harm than good.

'A lot of what's done is not based on good evidence,' says Dr. David Hahn, a family physician at the Dean Medical Center in Madison, Wisconsin, 'and a lot of physicians don't know that what they're doing isn't based on good evidence.'

Enter the evidence-based medicine movement, a concept that originated about two decades ago but has gained momentum in recent years as our overburdened health care system has floundered. The idea is to base clinical decisions on statistically and scientifically sound evidence, rather than on individual doctors' intuition or judgment--which has raised hackles among those who tend to value their judgment and intuition.

It's not that doctors are doing a bad job, proponents of evidence-based medicine say; it's that they often don't realize that their treatment choices are based less on evidence and more on their training, the philosophy of their practice, or their anecdotal experiences. To remedy these biases, evidence-based medicine looks to the 'gold standard' of research: the randomized controlled trial, which uses groups of randomly assigned study participants to compare the efficacy of different treatment approaches.