The Donors Choose challenge that you’ve been participating in has been doing great. We’ve raised a ton of money for projects for needy kids in Michigan (estimated reach this year is over 430 kids).
But the challenge will be over in less than a week, and some of the projects will be expiring soon. This one for example, will purchase audiobook equipment. They need $241 more, and they need it soon. Maybe we can make these kids happy in the next 18 hours?
We have some learning to do today, thanks friend of the blog, becca. The other day, I took issue with a press release published on another website. It was titled, Discovery may help scientists boost broccoli’s cancer-fighting power, which I found to by hyperbolic and deceptive. The actual study being reported regarded the ability of certain compounds found in cruciferous vegetables such as broccoli to be absorbed from the cecums of rats. I dismissed the entire piece as being unsupportive of its ambitious headline.
Becca took me to task for being too dismissive:
This is a paragraph from a review article (Keck and Finley, 2004) the manuscript cites:
“Epidemiologic studies have demonstrated inverse associations between crucifer intake and the incidence of lung, pancreas, bladder, prostate, thyroid, skin, stomach, and colon cancer.3 Prospective dietary assessment of 628 men diagnosed with prostate cancer found that increasing crucifer intake from 1 to 3 or more servings per week resulted in a 41% decreased apparent risk.7 A 10-year cohort study of 47,909 men reported that increased crucifer intake, but not fruits and other vegetables, was associated with decreased risk for bladder cancer (relative risk = 0.49, 95% confidence interval = 0.32-0.75, P = .008).6″
Those numbers are simply quite solid evidence, in the context of epidemiology. Is sulphoraphane the only compound in crucifers that is important? Of course not. But this epidemiology *combined* with the cell studies you so blithely write off strongly suggest that the long term goal of the scientist you take issue with “to increase bioavailability of sulphoraphane” is, in fact, a valid pursuit.
Reading and understanding the medical literature is not an art but a skill, one that must be learned. This learning never ends. When I run into studies I’m not sure I understand, I can run questions by my colleagues both online and in real life. For me, it’s always work, and I’m happy to be told when I’m wrong. Medical literature can be very different from other scientific literature, as it often focuses on risk, and reported measurements of risk can be quite deceiving (you may have to copy and paste the link address into a search engine). We also have to look at studies in the context of other studies evaluating similar questions. Because the results of medical studies often drive changes in practice that affect millions of people, we have to pay close attention to what risk and risk reduction really mean.
For this exercise, we’ll focus on the two main assertions quoted by becca (the assertions are from a review article published in a somewhat questionable journal, so separating theses assertions from folklore is particularly important).
Cruciferous Vegetables and Prostate Cancer (Odds ratios are confusing)
Study design is important. The type of study helps determine how association between two variables can be expressed.
The cited study is a retropective case-control study. This means that a group of patients with prostate cancer were compared to a group of similar men who did not have known prostate cancer, and they were asked to look back in time and report their intake of cruciferous vegetables over the last five years. This sort of study is vulnerable to recall bias, in which respondents’ memories may not accurately reflect the truth.
Looking at the numbers from Cohen study, comparing the ”most cruciferous eaters” and the “least cruciferous eaters” there is an (adjusted) odds ratio for prostate cancer of 0.59. You could say that the “broccoli” group had a 41% decreased odds of having prostate cancer compared to the broccoli-avoiders. But odds ratios are a tricky statistic and aren’t intuitive. For rare diseases, odds ratios are comparable to “relative risk”, a more intuitive number. But for common diseases (and prostate cancer is relatively common), an odds ratio can be deceptive. That’s one of the many reasons a prospective cohort study is more useful in this case, and such a study has been done.
The study cited below by Giovannucci took a sample of tens of thousands of males who were keeping track of their eating habits and at the end of the study period compared the intake records of those who did or did not have prostate cancer. This significantly stronger study found no significant association between cruciferous vegetable consumption and the risk of developing prostate cancer (although some of the subgroup analyses were tended toward interesting).
Bladder cancer (relative risk and number needed to treat)
In the Michaud study, comparing men who ate the most cruciferous veggies to those who ate the fewest, there was, as stated, a “relative risk” of 0.49. What does this mean? It means an absolute difference in risk for bladder cancer between the two groups of 0.038%. It also means that to prevent one cancer (number needed to treat) would require 2622 person-days of high-cruciferous diet. The initial 49% relative risk sounds big, but in real cases, it’s not a terribly significant number.
Compared to the prostate data, though, there is evidence from this and other prospective studies that consuming large amounts of cruciferous vegetables may have a small protective effect against the development of bladder cancers.
These subtleties are difficult, and definitely not sexy. But they are closer to reality. While it would be reasonable for me to tell patients that the sum of available data indicate that a diet higher in fruits and vegetables is probably healthier than a high-calorie, meat-based diet, there are not sufficient data for me to “prescribe” a high-cauliflower diet to prevent bladder or prostate cancer. They certainly don’t allow us to assume that “broccoli has cancer-fighting power” for us to “boost”. None of the studies looked at the specific use of any compound, just the use of vegetables.
It takes a long time for basic science to move into the clinic—for good reason.
References
Keck, A., & Finley, J. (2004). Cruciferous Vegetables: Cancer Protective Mechanisms of Glucosinolate Hydrolysis Products and Selenium Integrative Cancer Therapies, 3 (1), 5-12 DOI: 10.1177/1534735403261831
Cohen, J. (2000). Fruit and Vegetable Intakes and Prostate Cancer Risk Journal of the National Cancer Institute, 92 (1), 61-68 DOI: 10.1093/jnci/92.1.61
Giovannucci E, Rimm EB, Liu Y, Stampfer MJ, & Willett WC (2003). A prospective study of cruciferous vegetables and prostate cancer. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 12 (12), 1403-9 PMID: 14693729
Michaud, D., Spiegelman, D., Clinton, S., Rimm, E., Willett, W., & Giovannucci, E. (1999). Fruit and Vegetable Intake and Incidence of Bladder Cancer in a Male Prospective Cohort JNCI Journal of the National Cancer Institute, 91 (7), 605-613 DOI: 10.1093/jnci/91.7.605
Zeegers MP, Goldbohm RA, & van den Brandt PA (2001). Consumption of vegetables and fruits and urothelial cancer incidence: a prospective study. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 10 (11), 1121-8 PMID: 11700259
LabSpaces, a newer member of the science blogosphere, has some great bloggers. But as I recently pointed out, they’re failing miserably in one domain. LabSpace’s founder Brian Kreuger has an ambitious vision to create a sort of “facebook for scientists” (not his words). In his words:
LabSpaces.net is a social network for the scientific community designed to spread scientific news, maintain and create friendships, and harbor collaboration through the internet. The site serves as a web profile for researchers and labs, and is also a community for active communication in the sciences.
Included in his vision is, “a Science News feed updated daily with ~40 news articles.” This is where the problem begins. LabSpaces bloggers do what good science bloggers do, but the “featured article” section is a travesty. It is an uncritical regurgitation of institutional press releases and other PR documents. My interest is in proper reporting of medical information, and the articles consistently fail to deliver un-hyped and accurate medical information. The article that was the subject of my last critique was removed, along with the critical comment threat. Today he features another miraculous-sounding headline. How does this one measure up? Continue Reading »
I’m a medicine geek. I love it. I love going through cases in detail, developing a differential diagnosis, tossing around ideas with colleagues. Medicine is great fun. The professional organization for my specialty is the American College of Physicians, and we had our state chapter meeting recently. One of the highlights was a session where experts were given difficult cases to solve. These docs were sharp. They are all respected clinicians and researchers, usually department or division chiefs. Watching them work can be very humbling (well, not for them…).
There are no “grades” for doctors; your reputation is whatever your colleagues and patients say it is. I like to think that these opinions will roughly track with ability. What is certain, though, is that a real reputation can’t be bought. But that doesn’t stop people from trying.
One of the big stories this week was ProPublica’s Dollars for Doctors, an investigation into the relationships between pharmaceutical companies and doctors hired to speak for them. These docs are often touted as experts in their fields. What ProPublica found (and what is unlikely to surprise many doctors) is that many speakers are not exactly experts, and many are not exactly at the top of their fields.
Speaking for drug companies can be very lucrative. I’ve been approached a number of times, and given that even a few speaking engagements per year can significantly supplement the salary of a primary care doc, it’s not surprising that many say “yes”.
Having a financial relationship with a drug company is not prima facie unethical. But there are all sorts of ethical pitfalls, some subtle, some not, that emerge from such a relationship.
So, here’s a case:
You’re sitting at dinner and start to feel some indigestion. You burp a few times, but aren’t getting any better. In fact, you rapidly feel worse, and the “heartburn” starts to make your arm and neck ache. You start feeling panicked, and are having a little trouble breathing. Your spouse calls 911 and you’re brought to a tertiary care hospital where you are found to be having an “acute coronary syndrome”, but not an active heart attack. The ED docs put you on medications and transfer you to the cardiac unit. A cardiologist recommends going for an angiogram and possible stent placement in the morning.
Depending on the results of the angiogram, possible solutions to your problem may include coronary artery bypass graft surgery, angioplasty with stent placement (with either a bare metal or drug eluting stent) or medical therapy. There may be further findings that suggest the need for an implantable device such as a defibrillator or pacemaker.
The cardiologists at the hospital have seen their (substantial) incomes decline significantly over the last couple of years due to a combination of better treatment of heart disease (not as many people need expensive interventions) and cutbacks in what they are paid for diagnostic tests and other procedures. Some of the docs supplement their income by speaking for drug and device manufacturers. The department has a national reputation, however, with the cardiologists actively involved in research and publication.
You don’t have a lot of time to shop around.
What sorts of ethical problems might be involved here? Are the doctors’ judgments inherently invalid?
Remember some of the basic ethical principles: beneficence, non-maleficence, autonomy, justice.
There are a number of obvious questions here, but also a number of non-obvious problems. I’d like to hear what you think.
Reader and Donors Choose booster Jenny just posted this in a comment. I’m elevating it so that hopefully we can help these kids before the clock stops: Continue Reading »
The Doctor, Samuel Luke Fildes (1843-1927)
My residency program had a night float rotation. Three senior residents would be in the hospital from 11pm until 7am (more or less), each covering a different set of patients. We would run cardiac arrests, admit new patients, and put out various (metaphorical) fires. And we would pronounce patients dead. Each of us shared the duty, on a nightly rotation, of covering the inpatient hospice service. On one of my first night float calls, my pager went off, directing me to call the hospice unit. They asked me to come down and pronounce someone dead. I walked down the hall (no hurry, right?), got on an elevator, walked down another hall and into the calm, well-appointed unit, with its gentle lighting, living room couches, aquarium (at least, I think there was an aquarium). The nurses directed me to a corner room. The lights were low when I walked in, and a man was laying in the bed. His color was—wrong. Everything was wrong. I walked over and tried to wake him up, shaking him and calling his name. I took out a penlight and lifted open an eyelid, my fingers resting on his cold, sweaty brow. His pupils didn’t react. I placed my stethoscope on his chest and watched and listened for a long time. There were no breath sounds, no heart tones. He was most certainly dead. I called the attending physician and the family, waking them both, and sat down to do my part of the “death kit”, which included the death certificate. After a few jests with the nurses, I walked back out into the harsher light of the living.
I’d never felt more like a doctor than I did that night.
Note: Since publication, the referenced article has been removed without note. Some might argue that a more useful, nuanced, and sophisticated approach to posting a terrible blog post would be to leave the critical discussion intact and perhaps annotate or addend the offending post. But the memory hole is always tempting, no? –PalMD
From time to time, I write pieces rather critical of the way mainstream media cover science and medicine. Unfortunately for me, there’s nothing terribly unique about that, as there are a number of fine journalists and websites that do that every day, and do it well (see, among others, here, here, here, and here). Last year I had the good fortune to attend an event at USC’s Annenberg School of Journalism, and met a number of terrific journalists. One thing that is clear to me is that I don’t know enough about journalism. For one thing, I’m free of many of the pressures faced by mainstream journalists. I’ve broken ties with two media organizations that I’ve written for in the past (Scienceblogs and Forbes) because of the blurring of advertising and news/editorial content. As a full-time, practicing physician, I have that luxury. But many journalists do not.
During the Pepsigate scandal at Scienceblogs, I forced myself to think a bit more about what I want out of my own writing. I felt that if I am to continue to deliver accurate health information online, I’d better learn a bit more about journalism and about how reporters think and write. Blogging has become for me more than a simple hobby, but less than an actual journalism gig. I’ve found science writers to be an incredibly generous and approachable lot, and every day I strive to improve my writing, to show that there is no reason that a humble blog like this one cannot be a useful stop for decent writing on science and health.
Some have argued (I think correctly) that it may be impossible to be a practicing doctor and a practicing health care journalist, but I’m arrogant and crazy enough to think that I may be able to pull it off. Not that I think I can be a good full-time journalist, but I think I have something useful to add to coverage of science and medicine. I take my writing seriously, even though “it’s just a blog.” I would love to spend more time formally studying journalism, but hey, I have disease to stamp out, so I’ll just have to do my best.
And while not everyone will look at their own blogging as something delusionally serious, I think that people writing about health and science have to be ready to be taken to task for bad reporting. LabSpaces, a fairly new network emerging in this second wave of science blogging, has some terrific writers, but one of their projects is a disaster.
Many of us receive daily press releases and other announcements about the latest studies or breakthroughs. Journalists, with their particular education and experience, usually know how to view these critically. Usually. But we naive bloggers may succumb to the temptation to treat every press release as conveniently-delivered facts rather than the publicity and PR tools that they are. The folks at LabSpaces are falling into this trap.
The piece linked above is cribbed directly from a press release (I’m on the same mailing list) and is pure PR, with no supporting data or citations. It makes very bold claims (such as, “[scientists] have now scientifically demonstrated that strep can lead to brain dysfunction and OCD”). These are just the sort of claims that should lead a writer or journalist to either file away the info for later, or to contact the institution to ask some hard questions. To do anything else is to serve as a free publicity conduit.
So while you may not take your blog as seriously as some, others may. More and more, it seems, the mainstream media is blowing it on science coverage. There is no reason we should make the same mistakes.
Since Roger & Me documented the devastation of Flint, MI over two decades ago, things have gotten even worse. More than a quarter of the population lives below the poverty line.
But people try to survive, and one of Flint’s teachers is trying to help. She’s trying to purchase basic math and science supplies for her kids, kids whose families are often too busy trying to stay fed and housed to worry about non-immediately-vital needs like education. One of our most successful donors suggested we bump this project up the list, as it will expire in a few weeks. It will take another $411 to get this classroom the needed supplies. Even very small donations—$1-$5—make a big difference, and history has shown my readers able to round up a lot of money in small donations. Still, it’s a lot of money. Maybe we can get this one done before Friday?
Sixty years ago, the world was full of miracles. Western Europe was recovering from the devastation of World War II, an agricultural revolution promised to banish the fear of starvation in large parts of the world, and the mythical Mad Men era gave Americans a taste of technology-dependent peace and prosperity unlike any in the past. Despite the technological progress that would soon send animals into space and return them relatively unharmed, Americans, and westerners in general, were still dying of heart disease at a frightening rate. If you, as a middle aged American, experienced chest pain and were lucky enough to make it to a hospital (about 20% of all sufferers would die immediately), you would probably be given nitroglycerin and morphine to control you pain, put on bed rest, and could expect to live a few more years, with limited physical activity.
Heart disease continues to be a top killer of Americans, but there has been a dramatic decline in heart disease mortality in the last 60 years, with age-specific mortality rates dropping 60%. Fewer people are developing heart disease, and those that have it are living longer. It is estimated that in 2000 alone, there were 341,745 fewer heart disease deaths than would have been expected if rates had remained unchanged.
The trend has been going on for many decades, and has been accelerating, although current trends in diabetes and obesity put us at risk for more overall cases of heart disease in the future. So what are we doing right? How have we managed to cut the death rate from heart disease so dramatically?
Several studies have helped illuminate the answers. There have been different relative contributions from primary prevention (preventing new cases of heart disease) and secondary prevention (preventing recurrent cases). A recent study in the American Journal of Public Health analysed data from 1980-2000. The authors found that most of the reduction in deaths from heart disease (nearly 80%) were due to primary prevention, specifically decreasing smoking rates, and improvements in blood pressure and cholesterol levels. Society-wide reductions in smoking, blood pressure, and cholesterol are saving hundreds of thousands of lives in the U.S. every year.
The smoking rate in the US is still hovering around 24%. More than half of people with known high blood pressure do not have their blood pressure under control. This study shows us that we can easily prevent more heart attack deaths through education and through better adherence to extant treatment guidelines. Reducing heart disease deaths isn’t hard, and it won’t take miracles. We just have to want to do it.
*Similar trends have been seen in other English-speaking countries
References
Hurlburt CW (1927). THE CARDIAC CRIPPLE. Canadian Medical Association journal, 17 (11), 1305-9 PMID: 20316574
Sytkowski PA, Kannel WB, & D’Agostino RB (1990). Changes in risk factors and the decline in mortality from cardiovascular disease. The Framingham Heart Study. The New England journal of medicine, 322 (23), 1635-41 PMID: 2288563
FRY J (1964). CORONARY HEART DISEASE IN GENERAL PRACTICE: NATURAL HISTORY OVER TWELVE YEARS (1950-1961). Proceedings of the Royal Society of Medicine, 57, 39-42 PMID: 14114173
Centers for Disease Control and Prevention (CDC) (1999). Decline in deaths from heart disease and stroke–United States, 1900-1999. MMWR. Morbidity and mortality weekly report, 48 (30), 649-56 PMID: 10488780
Young, F., Capewell, S., Ford, E., & Critchley, J. (2010). Coronary Mortality Declines in the U.S. Between 1980 and 2000 Quantifying the Contributions from Primary and Secondary Prevention American Journal of Preventive Medicine, 39 (3), 228-234 DOI: 10.1016/j.amepre.2010.05.009
Wijeysundera HC, Machado M, Farahati F, Wang X, Witteman W, van der Velde G, Tu JV, Lee DS, Goodman SG, Petrella R, O’Flaherty M, Krahn M, & Capewell S (2010). Association of temporal trends in risk factors and treatment uptake with coronary heart disease mortality, 1994-2005. JAMA : the journal of the American Medical Association, 303 (18), 1841-7 PMID: 20460623
Once again, I’m amazed by the generosity of my readers. The huge project you funded which will give science supplies to an inner city school was finished just in time, and the giving frenzy was sparked by a very small donation. Small donations can do this—they become a nidus for more giving and from a moral standpoint are at least as good large donations.
The other thing that amazes me is that we (you, me, Scientopia readers) are doing really well in our competition with other groups of science bloggers. We are only a little bit behind mega-groups ScienceBlogs and DiscoverBlogs. The best thing about the contest is that kids win no matter what.
So keep the donations coming, especially the smaller ones. And here’s a great project for the donations: a teacher in an inner city school wants an aquarium so that her kids can observe frog growth and development. As a fellow blogger has pointed out, there are some significant successes out there in education. We can help build on these successes by helping talented, creative teachers elevate our children.
So, $224 by tomorrow will help another teacher help her kids. That helps all of us.
