Why big health advances rarely involve new medicines.

Health and medicine explained.
June 10 2008 1:36 PM

Old Drugs, New Tricks

Why big health advances rarely involve new medicines.

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The real problem for lagging specialties is that they possess numerous poorly studied, often recently approved drugs instead of a small core arsenal of older drugs that are well-understood and so can be dosed systematically. As the experience with leukemia shows, that's exactly the wrong way to cure disease. Successful specialties are anchored by centralized, rigorous professional organizations that served, over decades, as clearinghouses for study after study aimed at calibrating therapy. Thus, cardiologists depended on the Framingham Heart Study and the scientific committees of the American Heart Association, pediatric oncologists have the Children's Oncology Group, and children's lung specialists have the Cystic Fibrosis Foundation. These specialties don't pin all their hopes on new miracle cures; instead, they do the grunt work of incremental clinical trials with the pills they have. And as a result, they save many lives.

That doesn't mean duplicating these successes is easy. Just as no automaker has successfully copied Toyota's ingrained kaizen culture (which The New Yorker's James Surowiecki likens to a hard-to-follow "regular, sustained diet"), the incremental doggedness of certain medical subspecialties resists imitation. But the lagging subfields should try.

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Doctors in these fields first should take a long, hard look at their priorities. Lagging fields are often the scene of paralyzing turf battles between various institutions over clinical trials. By contrast, the more successful specialties have overcome such pettiness and forged nationwide partnerships to churn out study after study. The successful specialties also encourage studies that choose incremental goals over the big score.

In addition, many poorly studied diseases, psychiatric and otherwise, must be better defined. Doctors easily agree on whether a child has leukemia or a middle-aged man has a blocked coronary artery, and this makes it possible to contrast treatment differences—a key aspect of calibrating therapy. But surprisingly, despite all the editions and revisions of the Diagnostic and Statistical Manual of Mental Disorders, no standardized, reproducible diagnostic criteria exist for many psychiatric diseases, with the upshot that doctors often cannot agree on what's wrong with a patient. (In 2000, the British Journal of Psychiatry reported that researchers often make up their own definitions of schizophrenia to suit their agendas; for example, to make a certain drug look better.) The lack of objective diagnosis also plagues pediatric asthma, ear infections, attention-deficit disorder, migraine headaches, and food allergies, to name a few. And yet good definitions are a prerequisite to any study that compares treatments.

To help increase our incremental understanding of diseases and treatments, the federal government also must invest more in clinical studies of old drugs. For example, the world's first large study of antidepressants for bipolar disorder was published only last year, with funding from the National Institutes of Mental Health. It turned out that relatively newer drugs, like Paxil or Wellbutrin, didn't have much over old-school treatment with lithium or valproic acid. That's important for patients and doctors to know, and many more such studies are needed.

Without discounting the importance of new research, paying more attention to incremental improvement refocuses how we think about medical progress. And it's an upbeat shift in viewpoint, indicating that we already have the tools to cure many diseases and improve many lives. We just need to figure out how to use them better.

Darshak Sanghavi, a pediatric cardiologist, is a fellow of the Brookings Institution and Slate’s health care columnist. Follow him on Twitter.

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