March 14th, 2011 by GarySchwitzer in News, Research
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Here we go again. Headlines across America blaring lines like, “Coffee may reduce stroke risk.”
It was a big study, but an observational study. Not a trial. Not an experiment. And, as we say so many times on this website that you could almost join along with the chorus, observational studies have inherent limitations that should always be mentioned in stories. They can’t prove cause and effect. They can show a strong statistical association, but they can’t prove cause and effect. So you can’t prove benefit or risk reduction. And stories should say that.
USA Today, for example, did not explain that in its story. Nor did it include any of the limitations that were included in, for example, a HealthDay story, which stated:
“The problem with this type of study is that there are too many factors unaccounted for and association does not prove causality, said Dr. Larry B. Goldstein, director of the Duke Stroke Center at Duke University Medical Center.
“Subjects were asked about their past coffee consumption in a questionnaire and then followed over time. There is no way to know if they changed their behavior,” Goldstein said.
And, he noted, there was no control for medication use or other potential but unmeasured factors.
“The study is restricted to a Scandinavian population, and it is not clear, even if there is a relationship, that it would be present in more diverse populations. I think that it can be concluded, at least in this population, that there was not an increased risk of stroke among coffee drinkers,” he said.”
When you don’t explain the limitations of observational studies — and/or when you imply that cause and effect has been established — you lose credibility with some readers. And you should. Read more »
*This blog post was originally published at Gary Schwitzer's HealthNewsReview Blog*
January 3rd, 2011 by Michael Kirsch, M.D. in Opinion, Research
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The medical profession’s ability to diagnose far exceeds its ability to effectively treat the conditions discovered. Consider arthritis, Parkinson’s disease, irritable bowel syndrome, strokes, emphysema, and many cancers.
When a physician orders a diagnostic test, ideally it should be to answer a specific question, rather than a buckshot approach. A chest X-ray is not ordered because a patient has a cough. It should be done because the test has a reasonable chance of yielding information that would change the physician’s advice. If the doctor was going to prescribe an antibiotic anyway, then why order the chest X-ray?
Physicians and patients should ask before a test is performed if the information is likely to change the medical management. In other words, is a test being ordered because physicians want to know or because we really need to know the results?
Does every patient with a heart murmur, for example, need an echocardiogram, even though this test would be easy to justify to patients and to insurance companies? If the test won’t change anything, then it costs dollars and makes no sense. Spine X-rays for acute back strains are an example of a radiologic reflex. Read more »
*This blog post was originally published at MD Whistleblower*
December 21st, 2010 by Debra Gordon in Health Policy, Opinion
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“With this disappointing decision, the FDA has chosen to place itself between patients and their doctors by rationing access to a life-extending drug. . . We can’t allow this government takeover of health care to continue any longer.”
That quote, courtesy of this morning’s [Dec 17th] Washington Post, incensed me to such a degree that I am writing this blog despite the two deadlines I have today. The speaker is Sen. David Vitter (R-La). The “disappointing decision” he refers to: The FDA’s decision to remove the breast cancer indication for Avastin (bevacizumab).
I wrote about this earlier, and you can read the post here, but that was before yesterday’s [Dec 16th] decision. I’m not going to comment here on the benefits or risks of Avastin. . . except to say that I’m sure there are individual women who are alive today because of it, and, quite possibly, individual women who are dead today despite it. But that’s not how we do medical science, based on individual patients. We do medical science based on large clinical studies (which are often designed with and approved by FDA officials). It’s not a perfect system, but it’s the system we have. Read more »
*This blog post was originally published at A Medical Writer's Musings on Medicine, Health Care, and the Writing Life*
November 30th, 2010 by Elaine Schattner, M.D. in Better Health Network, Health Policy, News, Opinion, Research
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Over the long weekend I caught up on some reading. One article* stands out. It’s on informed consent, and the stunning disconnect between physicians’ and patients’ understanding of a procedure’s value.
The study, published in the Sept 7th Annals of Internal Medicine, used survey methods to evaluate 153 cardiology patients’ understanding of the potential benefit of percutaneous coronary intervention (PCI or angioplasty). The investigators, at Baystate Medical Center in Massachusetts, compared patients’ responses to those of cardiologists who obtained consent and who performed the procedure. As outlined in the article’s introduction, PCI reduces heart attacks in patients with acute coronary syndrome — a more unstable situation than is chronic stable angina, in which case PCI relieves pain and improves quality of life but has no benefit in terms of recurrent myocardial infarction (MI) or survival.
The main result was that, after discussing the procedure with a cardiologist and signing the form, 88 percent of the patients, who almost all had chronic stable angina, believed that PCI would reduce their personal risk for having a heart attack. Only 17 percent of the cardiologists, who completed surveys about these particular patients and the potential benefit of PCI for patients facing similar scenarios, indicated that PCI would reduce the likelihood of MI.
This striking difference in patients’ and doctors’ perceptions is all the more significant because 96 percent of the patients “felt that they knew why they might undergo PCI, and more than half stated that they were actively involved in the decision-making.” Read more »
*This blog post was originally published at Medical Lessons*
May 17th, 2010 by KevinMD in Better Health Network, Health Policy, Opinion, Research
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Let’s face it, the best way to cut healthcare costs is to say “no.” That means denying unnecessary tests that most patients in the United States are accustomed to having.
The New York Times‘ David Leonhardt has the best take on this issue that I’ve read. He acknowledges the difficulty of telling the American public “no,” and cites examples ranging from the breast cancer screening controversy to the managed care backlash in the 1990s:
This try-anything-and-everything instinct is ingrained in our culture, and it has some big benefits. But it also has big downsides, including the side effects and risks that come with unnecessary treatment. Consider that a recent study found that 15,000 people were projected to die eventually from the radiation they received from CT scans given in just a single year — and that there was “significant overuse” of such scans. Read more »
*This blog post was originally published at KevinMD.com*
