DC Medical Malpractice & Patient Safety Blog

When a diagnostic test result is negative, usually it’s cause for relief. But when the preliminary results of a study showed that nearly 9 in 10 MRI scans were negative, eyebrows were raised.

Not because the test results were questionable, but because of who owned the equipment used to conduct them. As described in a story on MedPage Today, the study, presented at a meeting of the Radiological Society of North America, involved patients who were sent for testing by physicians who had a financial interest in the MRI equipment.

It also showed that doctors with a financial stake in the device referred much younger patients for the test than those referred by practitioners who did not benefit financially from use of the imaging equipment.

It’s a pretty straight line from that set of data to conclude that docs with a financial interest in the medical device might be ordering unnecessary scans. So said the researchers. We have written about such conflicts of interest as well.

Increased spending on diagnostic imaging, one researcher noted, is due to several factors: imaging technology has improved, patients demand its use and clinicians are practicing defensive medicine (that is, ordering tests that might be of questionable need or usefulness in an effort to suppress lawsuits if somebody experiences an unwelcome outcome -- a concept that many of us challenge as more myth than reality). Two-thirds of the cost of imaging tests goes to the physician-owners, of whom only 1 in 3 is a radiologist. Hospitals and other providers get the rest.

That’s why the researchers decided to study whether nonradiologist clinicians who owned scanning devices were more likely to order imaging tests for, in this case, lumbar spine scans.

They reviewed charts for 500 such cases. Some of these patients were seen at a medical practice with a financial stake in the MRI and some were seen at one that did not. All scans were read by radiologists with no financial interest in the equipment.

They found no difference in the average number of lesions among scans that were positive (meaning that the severity of the problem was the same in both groups). The difference in the number of negative scans order by doctor-owners, however, was astounding. And the age difference in patients for that group was notable as well—they were more than seven years younger on average.

"We're not saying these studies are necessarily unnecessary, but when there's a clear difference between the scans ordered for these two groups, and the only difference is whether the [clinician] owns the scanner, that makes you think there's a tie," said one physician who served as an adviser on the research. "We're not sure if it's conscious or unconscious."
"Still," he said, "if the positives are the same, but one group has more negative scans, then at a minimum you have to wonder what the reason for ordering that scan is."

Yes, you do. You need, he said, stricter and more transparent information about scanner ownership. You need to re-examine federal Stark laws, which regulate physician self-referral of Medicare and Medicaid patients. Stark allows these programs to pay physicians for tests if the devices used are in their offices. You need, he said, to figure out ways to slow the growth of medical costs.

One way is to know whose pockets are lined when tests are prescribed that might not be necessary to solve a problem someone might not even have.

A new study might add to the perception that U.S. medical care is uncontrollably expensive thanks in part to unnecessary tests. “Screening by Chest Radiograph and Lung Cancer Mortality" concludes that people who have an annual chest X-ray do not have a significantly lower mortality rate than people who don’t.

The study, whose lung data are part of a larger investigation into cancers of the prostate, colon/rectum and ovaries, examined people who were given either annual chest X-rays (chest radiography) or standard medical care without screening. In the 13 years’ of the study, 1,696 lung cancers were detected in chest radiograph group and 1,620 lung cancers in the control group. The radiograph group reported 1,213 lung cancer deaths, and 1,230 in the control group.

The results weren’t really a surprise; researchers said the study confirmed expectations rather than setting new ones.

Some healthy patients believe that safeguarding their good fortune means having any screening that can yield information. Often their physicians accommodate them out of an abundance of caution, a desire to please the customer or a fear (usually irrational) of being sued if they are perceived to have practiced poor medicine.

But as with recent guidelines announced by the U.S. Preventive Services Task Force (USPSTF) about Pap tests, mammograms and prostate-specific antigen tests, sometimes a test, especially for generally healthy people, serves little purpose other than addressing professional insecurity and reducing one’s bank account. And in the task force cases, it can cause harmful side effects.

A smoker or someone with a family history of lung cancer might not qualify as someone who can ignore advice to get screened. But now, the best practice for people at risk for lung disorders might not be a chest X-ray. The recent National Lung Screening Trial concluded that early detection of lung cancer from a spiral CT scan reduced the risk of mortality.

A spiral CT uses X-rays to generate multiple images of the entire chest; a standard chest X-ray generates a single image of the entire chest in which parts of the anatomy overlie one another.

The National Cancer Institute study involved current and former smokers, and compared a CT scan group with a chest X-ray group, not people with no known lung problems or those who hadn’t been screened at all. Still, the best way to diagnose lung cancer doesn’t seem to be with a chest X-ray, and unless you’re having a respiratory issue, you don’t need one as part of your annual physical exam.

When you get up close and personal with your cellphone, what are you exposing yourself to, literally? Dangerous radiation? Maybe. Nasty germs? Most certainly.

Two studies examining different potential hazards of cellphones have been in the news lately. One concerns the ongoing debate about the radiation risks of extended close contact with your phone, and the other concerns its hospitality to surface germs.

The first study involved members of the advocacy group Environmental Health Trust and was published in the journal Electromagnetic Biology and Medicine. It says that exposure measures per FCC guidelines underestimate how much radiation most people receive from their cellphones, according to a story in the Los Angeles Times.

The study authors say that current assessment methods use a large, liquid-filled plastic model of the adult human head, but that more than 9 in 10 people have smaller heads and therefore higher proportional exposure than what is assessed. Most important, children receive twice as much microwave radiation to the head as adults, the study estimates, and 10 times the amount to bone marrow.

Not to mention the possible exposure to other body parts when, say, a phone is stowed in your pocket.

The scariest possible side effect of cellphone use is brain cancer, although whether microwave radiation from cellphones can damage DNA and cause cancer is a subject of debate. See the National Cancer Institute fact sheet.

The Electromagnetic Biology and Medicine paper requests that the cellphone industry use a different method to certify phones for use, one that considers different sizes of users, and those who are pregnant.

A Danish cellphone study found no relationship between cellular telephone use and the incidence of cancer, but the British Medical Journal found problems with some aspects of that study.

Bottom line, there are passionate researchers on both sides of this issue and we really have no definitive science to argue conclusively that cellphones do or do not pose a radiation risk. As in most things, moderation is in order. Use cellphones only as necessary, and store them, ideally, away from your body.

In contrast, it's unequivocal that your phone goes with germs like peanut butter goes with jelly.

As reported on WebMd, 9 in 10 cellphones in a United Kingdom study served as host to bacteria including E. coli. And the reason is simple: People don’t wash their hands after using the toilet.

In this study, the E. coli came from fecal bacteria, which can survive on hands and surfaces for hours.

The researchers studied cellphones in 12 cities across the U.K. and asked users about their hand hygiene. Here’s what they learned:

• 9 in 10 phones were carriers of bacteria


• 8 in 10 hands were carriers of bacteria


• 16 in 100 hands and 16 in 100 phones bore E. coli bacteria.

Still, nearly everyone said they washed their hands with soap where possible, leaving the researchers to conclude that people tend to lie about hygiene habits.

If dirty hands are touching cellphones, they’re also touching other surfaces. Said one of the researchers: “They're spreading fecal bugs on everything they touch really."

"We didn't ask people whether they'd used their phones in the toilet. That might be something that would be interesting to study," she said.

Well, interesting is an interesting word, but it definitely would be illuminating, probably in ways most people don’t want to know.

Wash your hands. Often. It’s really just that simple.

Another episode in the if-you-build-it-they-will-come (and pay) story of medical technology has been written recently by hospital emergency rooms. In 1996, about 3 in 100 ER patients were given a CT scan; by 2007, the figure had grown nearly fivefold, to 1 in 7 ER patients, according to a new study in the Annals of Emergency Medicine.

Does this greater diagnostic investment result in fewer people being admitted to the hospital — which is a good thing — or are CTs being overused, and padding the health-care bill without much payoff?

The hospitalization rate following a CT scan was 26% in 1996, and 12% percent in 2007. During that period, the overall hospitalization rate of ER patients rose from about 11% to about 13%.

The cost-benefit issue was examined recently by Kaiser Health News, not only in the context of cost, but because CT scans — which render a three-dimensional image by coordinating a series of X-rays taken from multiple angles — can subject patients to excess radiation.

The researchers, from the University of Michigan Health System, said the radiation risk could be higher for children, patients receiving multiple scans and those who develop complications from the intravenous dyes the imaging often requires.

The American College of Emergency Physicians claimed that fewer patients being admitted to the hospital can be attributed partly to the diagnostic tool.

Hard to argue with a technology that appears to help cut hospital admissions by half, but the study also finds that this positive effect of CT scanning “appeared to diminish after 2003” when the rate “flattened and stabilized” as CT use continued to rise.

Dr. Keith Kocher, the study’s lead author, said, “There are risks to overuse of CT scans … so if they’re done for marginal reasons you have to question why. For example, patients who complained of flank pain (pain in the side) had an almost 1 in 2 chance of getting a CT scan by the end of the study period. Usually most physicians are doing that to look for a kidney stone, but it’s not clear if it’s necessary to use a CT scan for that purpose.”

“Also, during the study period, [emergency department] visits increased by about 30 percent,” Kocher said, “while CT use increased 330 percent, meaning the rate of CT use grew 11 times faster than the rate of ED visits.”

Several factors contribute to the increased use of CT scans:

• the greater availability of the equipment;


• doctors’ fear of being sued for malpractice;


• a perception that patients want the test; and


• financial pressure to make use of the machine.

A handful of symptoms accounted for a disproportionate use of CT scans in the ER — impairments of nerve, spinal cord or brain function; flank pain; convulsions; vertigo; headache; abdominal pain; and general weakness. Approximately 1 in 4 CT scans performed in the U.S. is done in an emergency department, the study found.

If CT scans are overused, figuring out how to reduce their use is tricky, noted Dr. Robert Wears, an emergency medicine doctor who wrote an editorial accompanying the study. Such decisions, he said, are made on a case-by-case basis.

“What is acceptable and appropriate use or nonuse of CT imaging is not an entirely objective question that can be neatly resolved by empirical data and formal analysis,” he wrote, “but rather a tangled, socially constructed issue involving competing views of risk, benefit and obligation, and the elusive question of how much certainty we must have.”

The last thing an injured or ill person wants to do is engage in a protracted discussion about the suitability of care — he just wants to stop hurting. Still, when a CT scan is prescribed, Kocher advises patients to ask if it’s truly necessary. Or ask this: If the CT comes out one way, how will the care be different from how it would be if it comes out another way? Here's where the doctor may hem and haw. The doctor will probably still want to do the scan, and maybe she’s right. But the greater the awareness of the issue, the sooner a reasonable and appropriate standard of care can be determined.

Article first published as Why is Use of CT Scans Soaring in Emergency Rooms? on Technorati.

Hold your cellphone against your head too long and you can get a brain tumor. Text too often and you can forget how to spell. Converse on your Bluetooth while waiting in line and annoy everyone around you.

One of those statements is undeniably true, one could be true, and one—about brain tumors—is probably false, according to a new study in Environmental Health Perspectives.

Because data is sparse about cellphone use by youngsters and about use periods longer than 15 years, be prepared for ongoing speculation about how cellphones affect your brain. And be mindful, the study says, that "Research cannot in principle prove the complete absence of an effect, but only place limits on its possible magnitude.”

Still, the conclusion is fairly compelling: “Although there remains some uncertainty, the trend in the accumulating evidence is increasingly against the hypothesis that mobile phone use can cause brain tumours in adults.”

Of course, we can’t promise that somebody won’t whack you in the head if you text and chat during the movie.

Nobody wants to get lung cancer. Nobody who has it looks forward to the radical treatment such a diagnosis usually demands. But a recent research study lifted a bit of the dark cloud hovering over these patients. It found a significant decrease--20%--in deaths among lung cancer patients screened annually for three years with a certain type of CT scan compared with conventional chest X-rays.

This being lung cancer, and this being an evolving technology, caveats are in order: More than 90% of positive screening tests using both techniques were false positives, and the study did not assess the costs of false positive tests.

The high rate of false-positive results carries the potential for overdiagnosis and overtreatment. "Before public policy recommendations are crafted, the cost-effectiveness of low-dose CT screening must be rigorously analyzed," Christine Berg, M.D., of the National Cancer Institute, and co-authors wrote in their discussion of the results in the New England Journal of Medicine. "The reduction in lung-cancer mortality must be weighed against the harms from positive screening results and overdiagnosis, as well as the costs."

Approximately 157,000 Americans die from lung cancer every year; the study suggests that as many as 27,000 of them might be saved by CT screening. And although the key finding was that the technology resulted in fewer deaths, the study is notable as well for demonstrating no significantly harmful side effects. The landmark nature of the science was described by some authorities, including Dr. Otis Brawley, chief medical officer of the American Cancer society, as second in significance only to the surgeon general's 1964 report linking smoking to lung cancer.

Critical scrutiny now shifts from "does it help?" to "who does it help and how much does it cost?" Medicare pays about $300 for a CT scan, but positive results in lung cancer patients prompt additional testing, and where that ends is anybody's guess.

One observer casting a wary eye over not over the science but how it is represented to laypeople is Gary Schwitzer, blogging at MedPage Today. His beef isn't solely with the unknown costs of the increased use of CT scans, but in how the media chooses to present the findings with, in his estimation, little regard for the full story. Exemplary of such shoddy coverage, he says, is a national TV broadcast network for failing to offer any discussion of false positives and cost but sparing nothing in the hyperbole department. The network, he said, called CT scans "simple," a term with which he takes issue. Also, he said, "it cited a cost of a 'mere $99'--not to be matched in many locations across the U.S. and failing to take into account the follow-up costs of the considerable number of false positives."

Schwitzer claimed that the network "promoted screening advice that simply hasn't been established and didn't cite the source of that advice." He said it "offered to help viewers find hospitals who could scan them--journalism or advertising?"

Raising the flag of skepticism higher in hopes that the technology's end user--you, the patient--salutes, Schwitzer quotes Harry Demonaco, director of the Innovation Support Center at the Massachusetts General Hospital. The study, Demonaco says,"is really a tour de force that was masterfully crafted and operationalized. The authors presented the results in a well-balanced fashion. Unfortunately, the [broadcast news] report did not.

"There are 94 million smokers at risk for lung cancer in the United States today. According to the [study's] authors, only about 7 million of them would meet the eligibility criteria to have been included in the study. This is important because the results may not be generalizable to the remaining 87 million smokers."

Schwitzer concludes, "We know that journalists struggle with screening stories. A simple reminder may help them do a better job: All screening tests do harm; some may also do good. If you don't reflect that in your story, you're probably doing harm as well."

And might we just add: Harm comes in many forms--physical, financial and emotional. As a medical consumer, we hope you try to stay abreast of developments in medicine and technology that affect you and the ones you love. Remember, like everything else, if you read or hear news about something that seems to good to be true, you might not have the full story.

Children at emergency departments in the U.S. had five times as many CT scans in 2008 as they did in 1995, according to a recent study, increasing not only risks associated with radiation exposure but also risk of “incidentalomas," the term physicians use for incidental findings that could be (but probably aren't) cancer.

In addition, the study, published in the journal Radiology, found that 6% of pediatric visits to the ER involved a CT scan, while an earlier study by the same research group, led by Dr. David Larson at Cincinnati Children's Hospital Medical Center, found an even greater rise in scanning during adult ER visits, with 25 percent of patients age 65 and older and 12 to 16 percent of younger adults getting a CT scan in 2007. CTs of the abdomen and pelvis were the most likely to turn up an incidental finding.

An earlier study published in the Archives of Internal Medicine found that nearly 40 percent of CT and MRI scans performed for research purposes at the Mayo Clinic from January through March 2004 turned up at least one incidental finding. In the 35 patients in whom doctors took further action (i.e. additional testing, specialist consultation, or surgery), only six were judged by researchers to have clearly benefited from an investigation, while in the rest there was no clear benefit or clear harm, such as complications from surgery for a benign tumor.

In response to growing concern about the rising numbers of incidentaloma, the American College of Radiology recently published detailed guidance for clinicians about how to approach such findings, and warns physicians that “subjecting a patient with an incidentaloma to unnecessary testing and treatment can result in a potentially injurious and expensive cascade of tests and procedures." The college advises physicians to carefully consider an individual patient's risk for cancer in deciding whether or not to recommend further evaluation.

It also advised patients who are told about an incidental finding to seek a second opinion to verify that the radiologist's interpretation of their scan is correct, to adopt a "healthy skepticism" about testing, and only to consent to scans absolutely necessary to establish a diagnosis or plan of action, rather than to those ordered “just to be sure.”

Source: U.S. News & World Report

The medical community is waking up to an enormous problem with radiation – mainly X-rays and CT scans — used to diagnose disease and injury. Patients are getting too much radiation, and the excess itself causes injuries, many years down the road, in a big uptick in the risk of cancer.

Even a “routine” CT scan of the abdomen, ordered thousands of times every day in the United States for patients with belly pain, carries a large risk of downstream cancer, just from that single scan.

Dr. Rebecca Smith-Bindman, MD, of the University of California San Francisco, estimates a 20-year-old woman who undergoes a CT scan of the abdomen and pelvis has a one in 250 chance over her lifetime of getting cancer just from that single dose of radiation. This number was in a talk she gave recently at UCSF, as reported by her colleague Bob Wachter, MD, a patient safety expert at UCSF.

More scary statistics are in two articles Dr. Smith-Bindman and her colleagues published in Archives of Internal Medicine in 2009. There, they estimated that a single CT scan of the heart’s arteries (called a CT coronary angiogram, and promoted as being safer than the usual test called a cardiac catheterization) would cause cancer in one in 270 women and one in 600 men who underwent the test at age 40.

One problem is a huge range in the amount of radiation used at different facilities. Dr. Smith-Bindman’s group found a 13-fold variation from the lowest to the highest radiation exposure between scanners running the exact same imaging study.

She blames lax regulation by the Food and Drug Administration and lack of aggressive self-regulation by the medical physicists, working in hospitals, who are supposed to protect patients.

Most patients have no idea of the amount of radiation in one CT scan. It’s estimated to be about 200,000 times more than the radiation you get from going through an airport whole-body scanner, or about 450 times more than a simple chest X-ray.

Once people start to appreciate the risk, they realize that the pretty pictures produces by CT scans can have a very expensive cost down the road. It's something to remember the next time you see a billboard advertising “whole body scans” for healthy checkups, or “virtual colonoscopies” (to pick two examples of the heavily hyped types of CT scans now available).

Article first published as The Coming Cancer Epidemic from Overuse of CT Scans on Technorati.

A physician who gave nearly 100 veterans with prostate cancer incorrect doses of radiation has been sanctioned by the Nuclear Regulatory Commission (NRC). The errors involved the incorrect placement of iodine-125 seeds in patients to treat prostate cancer.

Out of 116 such brachytherapy procedures performed at the facility between 2002 and 2008, the VA reported that 97 were carried out incorrectly. The NRC investigation found that Dr. Gary Kao, a radiation oncologist at the VA Medical Center in Philadelphia, took part in 91 of the 97 incorrect procedures. In several cases, the incorrect doses were caused by Kao having implanted the seeds in nearby organs or surrounding tissue.

As a result, the NRC ruled that Kao cannot take part in agency-related activities without undergoing more training. The NRC also issued a separate order requiring Gregory Desobry, a medical physicist who worked at the same facility, to notify the agency if he accepts employment in that capacity involving NRC-regulated activities within 20 days of beginning such work. Last year, the NRC fined the Philadelphia VA hospital $227,500 over the incidents.

Source: Philadelphia Inquirer

To view a copy of the NRC decision, click here.

Why do patients who need focused, precise doses of radiation get walloped with huge overdoses that cause serious and even fatal injuries? A deadly combination of non-user-friendly radiation equipment, incompatible software when machines from different manufacturers are cobbled together, user error by the technicians administering the radiation, and lax regulation by federal authorities: All these are major issues in the ongoing expose by the New York Times of malpractice issues in radiation therapy.

In the latest installment, the team led by reporter Walt Bogdanich focuses on linear accelerators, machines that originally were intended to give broad-beam radiation doses to large swaths of the body, but now are increasingly modified to deliver what are supposed to be precise, focused radiation beams. The therapy is called stereotactic radiosurgery, and it allows hospitals who lack the more expensive competitor device, gamma knife surgery, to compete for radiation therapy business when the patient needs a very focused, intense dose to sensitive tissue -- such as a nerve deep in the brain.

But without proper setup, and without an easy way to see when the machine's beam has not been focused properly, tragedies can happen, as the reporters document.

One issue that this blog has focused on in other contexts with medical devices: The lack of a mandatory public registry to gather prompt reports of injuries and errors so that problems can be nipped in the bud rather than injuring patient after patient. The society of radiation oncologists is now asking for the creation of such a registry by the Food and Drug Administration. But the FDA lacks legal authority to force anyone other than a manufacturer to make a report.

How can patients protect themselves? Make sure the radiation unit you go to is well established, not brand new, and that the technicians are certified in the field of medical physics. More tips can be found in our previous article on the subject here.

X-rays in the dental chair carry a small but cumulative risk of causing cancer, and there are simple ways to reduce the risk.

One is to ask the dentist if he or she is using "fast" X-ray film, which allows a smaller X-ray exposure to get the same quality image.

The majority of dental offices still use the slow "D-speed" film, which the American Dental Association says should not be used. Better is to use E-speed or F-Speed, which can cut X-ray exposure by 60 percent.

Even better than film is digital imaging detectors which further cut radiation dose.

This and other tips are found in a New York Times article on high-dose radiation risks in dentistry, which are even greater with a new technology called cone-beam CT scanning, which creates 3-D images of the entire teeth and facial bones.

More questions to ask your dentist about radiation can be found in this list prepared by the Times reporters.

Read the whole report in the Times here.

The news about a major government study that found 20 percent fewer deaths in a group of heavy smokers who got annual CT scan screening for lung cancer has a few more statistics that are sobering for the rest of us who pay the price as a society for this screening.

The study enrolled 50,000 smokers and gave half of them CT scans and half regular chest X-rays, every year for three years.

All enrollees had to have had at least a thirty pack year history of smoking (that's the same as one pack a day times thirty years, or two packs a day times fifteen years).

After three rounds of screening -- a total of 75,000 CT scans in 25,000 patients -- they found a total of 18,000 suspicious findings that needed follow-up -- biopsies with long needles or some other kind of surgery. That was about a one-in-four incidence of suspicious findings per screen.

In those 25,000 people, eighty-eight lives were saved from lung cancer death. (The lung cancer deaths totaled 354 people in the CT group versus 442 in the control group of another 25,000 patients who got chest X-ray only for comparison.) That's where the 20 percent number came from for the headlines.

So, bottom line: take 25,000 people, give them 75,000 CT scans, do further testing and surgery and more followup on 18,000, and save 88 lives.

Now, those are 88 very hideous deaths prevented. Lung cancer is one of the worst. But the delicate problem is that it's also self-induced by smoking most of the time.

So who should pay for all this testing? That's the kind of thing we need to have a national conversation over -- not hysterical shouting about so-called "death panels" -- but what can we really afford?

You can read the data from the government agency here.

And to see how the news media handle the story, contrast the AP story "CT scans modestly cut lung cancer deaths," with the Washington Post ("significantly cut..."). Which is more accurate? It depends on how you focus your microscope. My vote is with the AP's writer.

It was nearly a year ago that the U.S. Preventive Services Task Force caused a huge uproar with the mildest imaginable recommendation about mammograms, and now two physician researchers say it might be time to point out that certain emperors are wearing no clothes.

In their Sounding Board article in the New England Journal of Medicine, Drs. Kerianne Quanstrum and Rodney Hayward note that some of the harshest cries against the Preventive Services Task Force came from those doctors with the highest vested self-interest in maintaining the importance of mammograms: radiologists with the Society for Breast Imaging. Yet nobody seemed to notice the obvious conflict of interest.

As the authors note:

When a given service is successfully extended to more people with more intensity, the profession providing that service tends to grow in importance and profitability. In the United States, where medical specialists often enjoy an exalted status in the minds of the public, if experts shout loudly that every woman 40 years of age or older must be screened annually for breast cancer, then breast cancer must be important, screening must be a basic human right, and doctors who provide this service must have great value and authority.

But what if those experts are basing their recommendations on more than the interest of patients alone? In any other industry, we accept the idea as natural that those providing a service or product hold their own and their shareholders' interests as a primary objective. Why have we failed to acknowledge that the same phenomenon occurs in health care? Although it is true that individual medical providers care deeply about their patients, the guild of health care professionals — including their specialty societies — has a primary responsibility to promote its members' interests. Now, self-interest is not in itself a bad thing; indeed, it is a force for productivity and efficiency in a well-functioning market. But it is a fool's dream to expect the guild of any service industry to harness its self-interest and to act according to beneficence alone — to compete on true value when the opportunity to inflate perceived value is readily available.

The objective facts, as Quanstrum and Hayward point out, are that the well known economics law of diminishing marginal returns applies in health care as much as anywhere. In mammograms, as the rareness of the tested condition increases, the hidden costs of the test goes up and the value goes down.

So for women between ages 60 and 69, you can save one life by subjecting only 400 women to mammogram screening (in the process of 5,000 screening visits and 400 false alarms in the same group over 13 years of follow-up). That's enough of a benefit to encourage everybody in the age group to get annual screening.

But in women between ages 40 and 49, the data show that to save a single life, you need to subject 1,900 women to screening and endure 20,000 screening exams with 2,000 false alarm tests during eleven years of follow-up. That puts the risk-benefit equation in more of a gray area where you cannot say definitely that no one should have it, or that no one should not have the screening.

And that was exactly the point of the Preventive Services' recommendation: To put the issue into the hands of individual doctors and patients and let them decide if family history or individual anxiety are enough to make the patient want to have the test. That's not a cop-out, it's a prudent bow to individual self-determination.

Here's another quote from Drs. Quanstrum and Hayward:

We must acknowledge that just as in any other profession or industry, self-interest is unavoidably at work in health care. Rather than even acknowledging practice guidelines offered by vested experts, we ought to borrow from the wisdom of sound governance and implement a system of checks and balances when it comes to the interpretation and application of medical evidence. At the same time, we need to recognize that these two tasks are distinct. Although the interpretation of medical evidence is (or ought to be) a scientific exercise, the application of that evidence, as in guideline formation, is ultimately a social exercise.

Decisions regarding practice guidelines can, and certainly should, be informed by evidence. But they will always require value judgments regarding how much evidence is sufficient to dictate care, for example, or whether and to what degree costs should be considered. By separating the processes of evidence review and guideline formation, fair disagreements about the quality or substance of the evidence can occur separately from, and before, disagreements about the implications for clinical care.

CT perfusion scans, often done on patients suspected of having a stroke, produce beautiful, detailed pictures of the human brain undergoing oxygen deprivation and tissue damage. But they don't do anything to advance treatment, according to candid radiologists. This adds a new layer to the story of massive radiation overdoses with these tests at some institutions with undertrained technologists and undertested machines.

Dr. George Lantos, an associate professor of radiology and neurology, Albert Einstein College of Medicine in the Bronx, explained it this way in a letter to the New York http://www.nytimes.com/2010/08/09/opinion/l09radiation.html?_r=1&ref=opinionTimes in response to the recent investigative piece on overdoses around the country:

One important point not emphasized in the article is that this is a case where diagnostic capability far exceeds accepted effective therapy. To date, the only widely used drug in acute stroke therapy is the clot-dissolving agent tissue plasminogen activator (tPA), approved by the Food and Drug Administration in 1996. The only imaging test required for the use of tPA is a computed tomography (CT) scan, done without the use of intravenously injected contrast material.

The purpose of the CT scan is to exclude brain hemorrhage, the presence of which frequently can’t be determined by physical examination alone. CT perfusion exams discussed in the article are very informative, giving precise, detailed images of the degree of nourishment of brain tissue and where such nourishment may be decreased during a stroke.

The problem is that there is no F.D.A.-approved therapy that uses the information from perfusion scans in the setting of acute stroke. Even the injection of the iodinated contrast material for this test is an “off label” application as far as the F.D.A.-approved package insert is concerned.

My stroke neurologists and I have decided that if treatment does not yet depend on the results, these tests should not be done outside the context of a clinical trial, no matter how beautiful and informative the images are. At our center, we have therefore not jumped on the bandwagon of routine CT perfusion tests in the setting of acute stroke, possibly sparing our patients the complications mentioned.

Dr. Lantos's letter highlights a frequent problem for expensive American-style medicine: imaging technology runs ahead of effective treatments. This is true for several other kinds of CT scans, such as "virtual colonoscopies" done with CT scanners, and similar scans done on the heart's arteries. In all these cases, careful questioning of the doctors will usually reveal that the results of the test will NOT change treatment one way or the other. The scans just yield nicely detailed images. For treatment, however, one has to look directly into the colon with a telescope-type device, or directly into the heart's arteries with a catheter.

The whole set of letters on this issue in the Times are worth reading.

One from the American College of Radiology talks about how mandatory adoption of the ACR's voluntary testing and accreditation program would go a long way toward reducing inadvertent overdoses.

Another talks about yet another aspect of unregulated, unnecessary radiation: from CT scans done in dentists' offices.