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*
March 8th, 2011 by GarySchwitzer in News, Opinion, Research
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We’re delighted to see that USA Today, Reuters, and WebMD were among the news organizations that included what an editorial writer said about an observational study linking ibuprofen use with fewer cases of Parkinson’s disease. All three news organizations used some version of what editorial writer Dr. James Bower of the Mayo Clinic wrote or said:
“Whenever in epidemiology you find an association, that does not mean causation.”
“An association does not prove causation.”
“There could be other explanations for the ibuprofen-Parkinson’s connection.”
Kudos to those news organizations. And some praise goes to the journal Neurology for publishing Dr. Bower’s editorial to accompany the study. His piece is entitled, “Is the answer for Parkinson disease already in the medicine cabinet? Unfortunately not.”
And unfortunately not all news organizations got that message. Because many don’t read the journals, so they certainly never get to the editorials. Instead, they rewrite quick hits off a wire service story. As a result, we end up with some of the following:
A FoxNews.com story was particularly deaf to Bower’s caveat, stating: “That bottle of ibuprofen in your medicine cabinet is more powerful than you may think.”
A CBSNews.com story never addressed the observational study limitation, instead whimsically writing: “Pop a pill to prevent Parkinson’s disease? A new study says it’s possible, and the pill in question isn’t some experimental marvel that’s still years away from drugstore shelves. It’s plain old ibuprofen.” Read more »
*This blog post was originally published at Gary Schwitzer's HealthNewsReview Blog*
January 26th, 2011 by GarySchwitzer in Health Tips, Opinion
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The February issue of Prevention magazine has an article entitled “Surprising Faces of Heart Attack” profiling “three women (who) didn’t think they were at high risk. Their stories are proof that you could be in danger without even knowing it.” No, their stories are not proof of that.
The story is about three women in their 40s. The story varyingly states that the three should have had the following screening tests:
— Advanced cholesterol test, carotid intimal medial thickness test ( CIMT)
— Advanced cholesterol test and stress echocardiography
— Cardiac calcium scoring and CIMT
There’s an accompanying piece: “7 Tests You’re Not Having That Could Save Your Life.”
I asked one of our HealthNewsReview.org medical editors, Harold Demonaco, director of the Innovation Support Center at the Massachusetts General Hospital, to review the two pieces. As his day-job title suggests, he deals with review of the evidence for new and emerging healthcare technologies. He wrote:
The section “7 Tests you are not having that could save your life” states: “If you have not had these cutting edge screenings, put this magazine down and call your doctor. Now.”
Wow. While much of the information is correct, it is the context that is disturbing. Suggesting that these tests are essential in everyone is a bit over the top. Some of the information provided for each test is basically correct. However in some cases the recommendations go well beyond national guidelines.
The major issue here is the tacit assumption that tests are infallible, without any downsides and are always a good thing. That is simply not the case. So who should get these tests? Read more »
*This blog post was originally published at Gary Schwitzer's HealthNewsReview Blog*
November 3rd, 2010 by GarySchwitzer in Better Health Network, Health Policy, News, Opinion, Research
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Continuing this week’s spontaneous theme (we didn’t make the claims and write the stories) of runaway enthusiasm for various screening tests by some researchers and journalists, HealthDay news service has reported on a study published in the Oct. 28 issue of the journal Nature that they say “provides new insight into the genetics of pancreatic cancer.” In the story, they let one of the researchers get away with saying, almost unchallenged:
“What’s important about this study is that it’s objective data in support of why everyone should be screened for pancreatic cancer.”
Mind you, this was a study that looked at tissue from just seven patients. The story continued with its breathless enthusiasm for the pancreatic cancer screening idea:
“In the future, new imaging techniques and blood tests will offer hope for early detection, the study noted. And just as people have a colonoscopy when they turn 50, “perhaps they should have an endoscopy of their upper gastrointestinal organs that includes an ultrasound of the pancreas,” said (the researcher).”
The very end of the story included some skepticism from Dr. Len Lichtenfeld of the American Cancer Society. Read more »
*This blog post was originally published at Gary Schwitzer's HealthNewsReview Blog*
October 5th, 2010 by GarySchwitzer in Better Health Network, Health Policy, Health Tips, News, Opinion, Research, Video
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We reviewed four stories on the Swedish mammography study that appeared in the journal Cancer last week. Three of the four stories gave a pretty clear indication that there were methodological concerns about the Swedish research (of the four reviewed, only HealthDay offered no such hint):
• 4th paragraph of AP story: “The new study has major limitations and cannot account for possibly big differences in the groups of women it compares.”
• 1st paragraph of LA Times blog story: “Critics charged that the study was poorly designed and potentially vastly misleading.”
• 2nd sentence of NY Times story: “Results were greeted with skepticism by some experts who say they may have overestimated the benefit.”
But none of the stories did a very complete job of explaining those potential limitations. Because of the confusion that must be occurring in the minds of women — especially those in their 40s — this is a time in which journalism must rise to the need and do a better job of evaluating evidence and helping readers make sense of what appear to be conflicting findings.
I was in Chapel Hill, North Carolina, when the study was published and had the chance to talk about it with former U.S. Preventive Services Task Force member, and a recognized thought leader on issues of prevention and especially of screening tests, Dr. Russell Harris, Professor and Director of the Health Care and Prevention Concentration of the University of North Carolina (UNC) School of Public Health. Read more »
*This blog post was originally published at Gary Schwitzer's HealthNewsReview Blog*
