Last reviewed and revised February 27, 2013
Have you ever noticed that when medical research is described in the news, the last line is usually a disclaimer about how more research is needed? It sometimes seems surprising given the positive results and often dramatic implications of what is being presented. Why the seemingly endless need for more study? Why the delay — often years — in getting "breakthrough" research results into practice? As illogical as it may seem, there are good reasons.
You've Heard This Before: The Big Qualification
Imagine you are watching the news on television and the health portion of the broadcast begins:
News anchor: "Researchers at the University Medical School believe they have isolated a protein responsible for aging in the nervous system. For more on this story, we go to our Eyewitness News medical reporter, who is live on the scene with the lead investigator of this groundbreaking research."
Reporter: "Tell us about your startling discovery, professor."
Professor: "Well, it appears that we have isolated a protein from the brains of aging, demented mice. You see, younger mice and normal elderly mice did not have as much of this protein in their brains. We've also found that mice with flaxseed in their diet have less of this protein in their brains and they seemed to be smarter. We are hopeful that these discoveries will lead to better detection and treatment of Alzheimer's disease in humans."
Reporter: "Fascinating, thanks so much for sharing this news with us. (Facing the camera). And, so, thanks to these dedicated researchers, there is new hope today for the millions of people with Alzheimer's disease and related conditions. And now, back to the news desk."
News anchor: "Thanks. Other area neurologists say they are cautiously optimistic about these findings. Researchers caution that it may be several years before it is known whether the newly discovered protein or any dietary treatment might be helpful for humans."
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Why So Cautious?
So why the big letdown at the end? There are two main reasons that researchers seem to back away from sweeping conclusions at the end of a story.
For one, research tends to make advances in small steps, many of which may be dead ends. Many promising research studies end up going nowhere. In addition, research that makes the news is often preliminary, based on only a few human subjects, or on animals. Whether such findings will apply to the "average human" with that condition initially remains uncertain.
Even so, researchers want their ideas and findings to be known — after all, that's how ideas are spread among others in the field and that's how the researchers advance their reputations, get promoted and attract funding for additional research. In order for research to have its intended effect, people have to know about it. So there is a tendency to publicize small, preliminary studies well before their impact is entirely clear.
The other reason stems from the perspective of the news media: They want an audience. So, there is a tendency to present even the most preliminary research results in a dramatic and positive light. And that may be acceptable, as long as the specific information presented is accurate. In addition, the media have a responsibility to provide some form of disclaimer when the findings are of unknown importance and years away from availability.
One other factor that may play into this is that hope is a powerful motivator and no one wants to take it away. It's difficult to hear even preliminary news about diseases that may have seemed hopeless in the past without "spinning" it in a positive and hopeful light — but that makes qualifying comments about the need for additional study even more important.
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The Hazards of Preliminary Results
When presented in news bites, research results often seem straightforward, but the dangers of overstating results are well known to anyone involved in medical research. Among the most common hazards are:
- The results could be erroneous. Even the most elegant research performed by the smartest and most careful researchers comes with the possibility that the results may be flawed. Errors may occur for numerous reasons, including flaws in measurement, bias (that is, a flaw in study design that alters the results to favor one outcome over another), or just random chance. While there are ways that researchers can account for such problems, it is nearly impossible to exclude at least a small amount of error.
- The results could be accurate, but unhelpful. For example, if a study finds that a medicine improves arthritis in dogs, the findings might be perfectly true. But until human studies are performed, the findings themselves are not yet helpful.
- The results could be less relevant because of new therapies that became available after the study was started. For example, suppose a study showed a certain prevalence of disability for people with rheumatoid arthritis over a 20-year time period. But the results would be outdated if new, powerful drugs to treat rheumatoid arthritis were approved years after the study began.
- Finally, results could be true but lack a practical application. A commonly quoted study in the New England Journal of Medicine found that an antibody (called the antinuclear antibody) may be present many years before the onset of lupus. That may be useful to researchers studying how the disease begins and someday could have an important application to lupus patients. Right now, however, this knowledge does not help us to diagnose or treat the disease.
A single study is rarely convincing and needs to be confirmed by other researchers in other settings. If the findings cannot be repeated, it does not prove that they are incorrect, but it does raise that possibility.
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Why the Answers Take a While
Human studies that actually provide useful information are often very difficult to perform. Multiple steps are involved. Care must be taken to prove safety, then effectiveness, before human subjects are enrolled for medical research. In the end, the ideal outcome may be impossible to measure. For example, an ideal study of a new treatment for dementia would include periodic biopsies of the brain. Of course, that won't happen because of the risk involved. Instead, brain scans, detailed questionnaires and other tests of brain function may be checked every few months as indirect measurements of potential improvement.
For all these reasons, studies in humans take a long time, tend to have fewer study subjects than might be ideal, and are prone to error at many points along the way.
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The Bottom Line
It may seem as though medical researchers and the reporters who bring their stories to you are inordinately conservative, unwilling to announce sweeping conclusions that make a big impact on your immediate health. But the stakes for medical researchers are high. Being wrong could be dangerous to the health of research subjects and future patients; it also could jeopardize the researchers' reputation and that of the academic sponsors and funding sources.
Despite how it may be presented, medical research you read or see on the news is not necessarily the next big thing — even the researchers themselves usually will admit that. And that's what the medical reporter and the medical researchers are saying when they qualify even the most promising medical news.
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Robert H. Shmerling, M.D. is associate physician at Beth Israel Deaconess Medical Center and associate professor at Harvard Medical School. He has been a practicing rheumatologist for over 20 years at Beth Israel Deaconess Medical Center. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program.