The Case for Evidence Based Medicine

In for a dime, in for a dollar, my father always said—so since I already have what seems like every psychologist in the country furious at me for writing about a report that takes the profession to task for practicing forms of therapy that have no scientific support, and half the doctors annoyed at me for noting the disconnect between what treatments they offer and which ones are supported by solid empirical evidence, I'll wade into these treacherous waters yet again. By "treacherous waters," I mean evidence-based medicine (EBM): choosing treatments based on the clinical evidence that they work. (Click here to follow Sharon Begley)

This, of course, has become a huge theme in the current health-care debate, since rejecting treatments without such support, and sticking to those shown to work, promises to reduce the country's health-care bill. Of course, practicing medicine should not be like following a cookbook recipe. If doctors conclude that an individual patient is very different from those in studies that showed a particular treatment to work, they might be justified in treating that patient with something other than the EBM-supported drug or procedure. The trouble is that too many doctors think they have exceptional patients.

My thoughts have turned to EBM again because the Cochrane Collaboration, an international consortium that evaluates medical research, has released its latest reviews. Scanning them, you can't help but despair at how many ineffective, useless treatments patients get. Just to be clear, that's not intentional: the realization that something doesn't work, or that it doesn't work as well as something else, comes slowly, only after years of research on thousands of patients. But that's why we need more of this, fast—and why it got $1 billion in the federal stimulus bill last winter.

You can find all the latest Cochrane evaluations of various treatments here, but let me mention some of the more interesting:

* Opioid drugs for hip and knee pain caused by osteoarthritis? Bad idea. "We found that pain reduction with opioid treatment was small to moderate. Increasing the dosage did not appear to result in further pain reduction," said Eveline Nüesch, a research fellow at the University of Bern in Switzerland, who led the Cochrane review on this. "However, patients taking opioids have large increases in risks of experiencing adverse effects," such as nausea and constipation. Added Nortin Hadler, professor of medicine at the University of North Carolina at Chapel Hill and spokesperson for the American College of Rheumatology, "It is striking how little additional benefit patients with hip or knee pain can expect from taking opiates compared to placebo." Pain, of course, is among the conditions most susceptible to a placebo effect. The thumbs-down on opioids is based on 10 studies comprising 2,268 patients.

Question: will doctors stop prescribing opioids to most of their osteoarthritis patients? Will patients, believing in the power of these drugs, sit still for plain old acetaminophen, which Hadler calls "as good as it gets"? (Similarly, despite 20 years of research on electrostimulation for osteoarthritis of the knee, it's not clear that it reduces pain or physical disability.) It would be interesting to see the annual bill for the pointless use of opioids.

* On bulimia (which affects about 1 percent of women) and binge eating disorders (2 to 5 percent), the verdict is more optimistic: psychological treatment can help a lot, and cognitive behavioral therapy (CBT) is the most effective talk therapy. That's based on 48 studies with 3,054 participants. CBT (typically, 15 to 20 sessions over five months) helps patients understand their patterns of binge eating and purging, recognize and anticipate the triggers for it, and summon the strength to resist them; it stops bingeing in just over one third of patients. Interpersonal therapy produced comparable results, but took months longer; other therapies helped no more than 22 percent of patients. If you or someone you love seeks treatment for bulimia, and is offered something other than CBT first, it's not unreasonable to ask why. Cynthia Bulik, director of the University of North Carolina Eating Disorders Program, summarized it this way: "Bulimia nervosa is treatable; some treatment is better than no treatment; CBT is associated with the best outcome."

* Contrary to the suspicions of critics, comparative-effectiveness research isn't all about ratting out therapies that don't work. It can also identify those that do, even when they're expensive. Case in point: abatacept, a new kind of drug that targets immune cells, is indeed effective against rheumatoid arthritis. You might assume that that's a given, since the FDA approved the expensive drug. But when a drug enters widespread use it sometimes turns out to be less effective than initial studies showed (antidepressants are a prime example of this), or less safe (Vioxx). But in this case, based on seven studies with 2,908 patients, abatacept was twice as likely to reduce pain, tenderness and swelling by 50 percent, compared to other drugs.

* For stress urinary incontinence in women, surgery is a last resort when pelvic floor muscle training and drugs fail. The good news: the minimally invasive form of the traditional "sling operations," in which strips of material are attached to muscles and ligaments under the urethra to form a sling, is just as effective as the more invasive procedure, with cure rates of 80 percent, at least in the short term. The finding is based on an analysis of 62 trials with 7,101 women.

* Not that this one will make much difference in our vitamin-crazed society, but taking B vitamins doesn't prevent heart disease. In principle, you might think they would (and vitamin companies and health-food shops are happy to encourage that belief): B12, B9 (folic acid) and B6 all influence levels of homocysteine, high levels of which are associated with an increased risk of heart disease. But according to eight trials with 24,210 people, B-vitamin supplements do not reduce the risk of cardiovascular disease and death.

Now that we all research our illnesses online, the Cochrane reports are a good place to start. Let me add a final, historical note. The Cochrane consortium is named for Archie Cochrane, a British epidemiologist and physician who died in 1988. As a young doctor, he cared for tuberculosis patients, and was dismayed by the paucity of research on effective treatments. He wrote, "What I decided I could not continue doing was making decisions about intervening (for example pneumothorax and thoracoplasty) when I had no idea whether I was doing more harm than good. I remember reading a pamphlet ... extolling the advantages of the freedom of British doctors to do whatever they thought best for their patients. I found it ridiculous. I would willingly have sacrificed all my medical freedom for some hard evidence telling me when to do a pneumothorax."

Cochrane's dedication to evidence-based medicine infuriated his colleagues, who valued freedom to do what they wanted over being guided by effectiveness research. If history repeats itself first as tragedy and then as farce, we are in real danger of making too much health care the latter.

Sharon Begley is NEWSWEEK's science editor and author of The Plastic Mind: New science reveals our extraordinary potential to transform ourselves and Train Your Mind, Change Your Brain: How a New Science Reveals Our Extraordinary Potential to Transform Ourselves.

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