Tuesday, February 28, 2006

Under appreciated vascular complications of giant cell arteritis

Thoracic and abdominal aortic aneurysm, aortic dissection and limb artery stenosis are not uncommon. Such complications can present during the active treatment phase or years later. According to this review (Current Opinion in Rheumatology) 1 in 5 patients with GCA will develop an aortic aneurysm and 1 in 16 will dissect. A strategy for screening and surveillance is presented.

Cerebral palsy verdict could close hospital

“Tyrone Hospital said in a court petition filed Monday that it will declare bankruptcy or close its doors if a Blair County judge does not reduce a $4 million verdict awarded by a jury two weeks ago.” Read the rest here.

Monday, February 27, 2006

The propagation of the absurd in mainstream medicine

Wallace Sampson and Kimball Atwood put aside political correctness and pull no punches in their criticism of mainstream medicine’s widespread uncritical acceptance of unproven and implausible alternative claims. Their uncompromising viewpoint on complementary and alternative medicine (CAM) appears in the December issue of the Medical Journal of Australia (MJA). I’ve been hammering away in the pages of this blog trying to issue a plea for scientific integrity in medical education and in our healthcare institutions for some months now. I haven’t succeeded nearly as well as these authors have. A few of their points will be mentioned here.

The authors blame postmodernism for much of the uncritical acceptance of CAM, noting that postmodernism tolerates multiple and contradictory ways of thinking, “without need for resolution through reason and experiment, resulting in a medical pluralism.” I made a similar point about postmodernism driving alternative medicine in a previous post.

Detractors are fond of saying “but medical students need to know about these things” or “they’re doing research”. Trouble is, much of this so called “education and research” amounts to little more than uncritical promotion of quackery. I’ve given examples before, and the authors of the MJA piece make the case effectively. They cite data, for example, that of the 175 medical school CAM courses in existence only 4 take a critical approach. This means that the vast majority of curricula promote unproven and implausible methods, implicitly if not directly. Moreover, Medline abstracts overwhelmingly promote, and few if any critique CAM. They also note that the NIH web pages link only to promotional CAM sites as opposed to objective critical sites like Quackwatch.

Finally the authors address the problems inherent in researching biologically implausible claims by urging a Bayesian approach in which research findings are interpreted in light of prior knowledge and plausibility.

Read the article in the original and bookmark it as a powerful expose of pseudoscience.

Targeted statin therapy versus usual care: The ALLIANCE trial

Recently published in the American Journal of Medicine, the study compared a formal strategy of treating to new aggressive LDL targets (<80 mg/dl) with “usual care.” The formal strategy used atorvastatin in doses up to 80 mg daily and was associated with improved cardiovascular outcomes. It is not clear how many of the usual care patients received statin drugs, but apparently a substantial number. 66% of all patients were on lipid lowering medications at study entry. The usual care group achieved an average post treatment LDLC level of 111 mg/dl as opposed to 95 mg/dl in the formal treatment group. Treatment adjustments in the usual care group were at the discretion of the primary physician, to simulate “real world” conditions.

Usual care in this study, achieving an average LDLC of 111 mg/dl, was surprisingly good. Nevertheless the formal targeted strategy was better. To me this finding speaks strongly for the use of dedicated lipid clinics. I know of no better way to apply these results to community practice. Finally, these results are in marked contrast to the lipid arm of ALLHAT which found pravastatin 40 mg daily to be no better than usual care.

Sunday, February 26, 2006

Differential diagnosis resources

Although I trashed last week’s controversial New York Times article about misdiagnosis the article was not totally devoid of substance. It pointed me to Isabel, a web based differential diagnosis reminder system. It’s named after Isabel Maude, the girl with chicken pox and a delayed diagnosis of necrotizing fasciitis who was profiled in the New York Times story. When Isabel was on the mend at the tertiary care center, staff there began hinting that the case had been mishandled. The parents were angry and friends urged them to sue. Instead, Jason Maude decided to direct his energies more constructively. He founded a software company to develop a program to help physicians improve diagnostic accuracy.

How does it work? Typing in the patient’s presenting signs and symptoms yields an extensive list of possible diagnoses, with the idea that the physician will be reminded of rare diseases or uncommon presentations of more common diseases which might otherwise be overlooked. Isabel started out as a pediatric resource but has since been expanded to include adult medicine.

Other differential diagnosis resources are out there. I’ve had some experience with Dxplain, a program from Mass General. Although Dxplain is primarily licensed to institutions, a free portal is available for individual subscribers to Merck Medicus. I occasionally use Dxplain and have signed up for a free trial of Isabel. I’ll plug a few cases into both programs for comparison and report back soon.

Meanwhile the web version of the New York Times article links to an audio interview of Jason Maude. (Check the left sidebar). He discusses his daughter’s case and the history of development of the Isabel program. It gets a little self promoting at the end. Jason suggests patients ask their doctor “Have you tried Isabel?” There’s talk of developing a consumer version. Now that could get interesting. Imagine your patient with gastroenteritis telling you “I did an Isabel search and it told me vomiting can be due to a cerebellar tumor or hemorrhage. I want an MRI.”

Canada’s struggle for health care quality

The Institute of Medicine’s Quality Chasm report stresses that health care must be timely and patient centered. How’s Canada doing? They’re trying, but non-emergency health care there is anything but timely. Newly announced federal wait time benchmarks, hailed as a major improvement, are deemed inadequate by Canadian physician specialty groups according to this report in CMAJ. They include cancer irradiation within 4 weeks, hip fracture repair within 48 hours, hip and knee replacement within 6 months, cataract surgery within 4 months for high risk patients, and coronary artery bypass surgery in 2 to 6 weeks in high risk patients. And that’s considered improvement.

Worse, there’s a wait time for the improvements. Canada’s provinces were given 2 years to set implementation targets.

Resolution of pulmonary emboli

This study in Chest questions the conventional wisdom. We assume pulmonary emboli resolve, and those few whose emboli do not are the ones destined to get chronic thromboembolic pulmonary hypertension. But this systematic review indicates residual thrombi present in 87% of patients at 8 days following diagnosis and 52% at 11 months. The authors suggest re-imaging after treatment to establish a baseline. I’m not sure how it applies to the real world. The study has its flaws---only 4 of 29 papers of widely varying methods were included in the analysis.

Saturday, February 25, 2006

Why do newspapers so often get it wrong?

There’s been some fallout from the New York Times article this week on misdiagnosis. Evidently the NYT got wind of their error of describing a case of necrotizing fasciitis as a flesh eating virus. Although they published no acknowledgement of the error, at least that I can find, they’ve changed the wording of the web version to read “flesh eating infection.” They were so sneaky about it that I began to doubt the accuracy of my own reporting. Had it really said virus? I tried Google’s cache and the Wayback Machine to no avail.

Finally I found a paste of the original version on the UCSF Emergency Medicine List where there is a lively thread. Indeed the original NYT version described the flesh eating infection as a virus. Several doctors on the UCSF list object to the article’s comparison of health care to the airline industry. One writer, Bob Solomon, said “Airplanes are machines. Patients and their families are people. Comparisons are absurd.”

What Isabel Maude, the girl with the flesh eating infection, actually had was chicken pox complicated by Group A Streptococcal necrotizing fasciitis and toxic shock syndrome. DB weighed in and one of his commenters made a good point about necrotizing fasciitis. He said “I can’t believe that the NYT could not come up with a better example of ‘misdiagnosis’ than that. The kid DID have chicken pox, complicated by necrotizing fascitis (a bacteria Ms. New York Times reporter, not a virus). This was an example of incomplete diagnosis, not misdiagnosis. Also, necrotizing fascitis can move incredibly fast, so who is to say that it was present at a detectable stage when the patient first presented.”

Finally, a commenter at Kevin MD questioned the accuracy of autopsy data in assessing diagnostic error: “Finally, because the rate of post-mortem exams is now so low, only cases with some uncertainty are subject to this final check. The application of the post-mortem exam is not a randomly assigned process, but is selected by the presence of strong clinical uncertainty on the part of physicians and/or family.” Well said.

The nuts and bolts of troponin measurement

Troponin is a reliable marker for cardiac injury but questions often arise. What non cardiac conditions are associated with elevations? What is the significance of elevated troponin levels in renal failure? After PCI, ablation procedures or cardioversion? Here in CMAJ is one of the better troponin reviews this blogger has seen.

Friday, February 24, 2006

Why are smart people so stupid about health claims?

Maybe it’s a failure of our educational system, suggests this writer. There’s too much effort to teach us what to think rather than how to think. Even college education seems to have a minimal impact on people’s beliefs in ESP, astrology and alternative medicine according to one survey.

Thursday, February 23, 2006

New York Times on misdiagnosis: a follow up

My post about the NYT article on misdiagnosis sparked discussion by commenters and other bloggers. I wrote that pay for performance (P4P) has not been demonstrated to improve quality. An anonymous commenter said “Uh, the study DID show improved screening rates for cervical cancer (at least according to the abstract).” To elaborate: three measures, cervical cancer screening, mammography, and hemoglobin A1C measurement were analyzed. After implementation of P4P there was no difference in improvement for two of the three measures. Cervical cancer screening showed a modest difference in improvement (3.6%). Moreover most of the bonus money went to providers already above the quality thresholds at baseline, who demonstrated little improvement. I stand corrected for not having nuanced my statement about the study findings, although these data do not make a convincing case that P4P improves quality. Perhaps we can agree, at the risk of being trite, that more study is needed.

Kevin linked to my post. One of his commenters, Dr. Hebert, pointed out the absurdity of rewarding or penalizing doctors for outcomes. He said “If doctors are paid by outcome, patients that have diseases with poor prognoses, like liver cancer or spinal injuries, will find themselves unable to find a doctor.”

Hippocrates at health voices weighed in with “Fighting the public's perception that there is room for improvement in health care quality is a losing proposition, both politically and economically. Skyrocketing health care costs make demands for accountability inevitable.” Hippocrates may have missed my point. I would never argue against room for quality improvement. I was merely taking the New York Times to task for distorting the facts. Talking about incentivizing quality, the Times piece says “For a politician looking to make the often-bloodless debate over health care come alive, this is a huge opportunity.” Is the author looking for a political football or a blood bath? That’s the problem I have with this piece. Can’t we keep the health care debate sober and factual?

Hippocrates also said “Pay-for-performance is an easy concept for the public to grasp and ignoring this is an indefensible position.” Ignoring it is one thing; asking for proof is another. What’s missing from this discussion is consideration of the cost of widespread adoption of P4P with incentives that are meaningful. Once the public grasps the true cost how will they perceive it?

Alternative medicine is not harmless

An outbreak of cutaneous Mycobacterium abscessus infection was traced to an acupuncture clinic, as reported in BMC Infectious Diseases.

The open access movement

There is a burgeoning drive for more free access to on line scientific publication. Here’s a blog devoted to the issue, which has links to open access resources.

Wednesday, February 22, 2006

Newspaper hype versus clinical reality

A February 22 New York Times article entitled “Why Doctors So Often Get It Wrong” (registration required) deals with the problem of medical diagnostic error. Claiming that medicine suffers from a “misdiagnosis crisis” the article asks “How can this be happening? And how is it not a source of national outrage?”

We are told the story of a little girl who suffered consequences of delayed diagnosis. The New York Times piece states that the girl, diagnosed as chickenpox, actually turned out to have a flesh eating virus which her doctors failed to diagnose until her organs started shutting down. Hmmm----what’s a flesh eating virus anyway? Chickenpox is a virus. Did the doctors diagnose the wrong virus? A more accurate BBC report indicates that the girl actually had chickenpox complicated by necrotizing fasciitis, a bacterial infection.

With that little trifle out of the way let’s consider the article’s major premise about misdiagnosis. The article mentions autopsy data showing a 20% misdiagnosis rate, with JAMA as the source. Although the Times gives no citation, the JAMA article in question is probably this systematic review of autopsy-detected diagnostic errors. What the Times neglected to point out is that although the JAMA analysis found a 23.5% error rate, the rate of errors likely to have affected outcome was only 9%. Moreover, while the Times article claims that the error rate has not improved since the 1930’s the JAMA study found a continuous decline in the error rate between 1966 and 2002.

Although the Times article suggests that pay for performance and penalties for errors might solve the “crisis” the data suggest otherwise. Studies on Pay for Performance to date have failed to demonstrate improved quality. A spate of articles analyzing medical error indicates that promotion of a culture of blame by penalizing doctors for honest mistakes is counter productive.

The JAMA perspective is more nuanced: “However, it remains unclear to what extent clinically missed diagnoses represent errors per se, rather than acceptable limits of antemortem diagnosis in the face of atypical clinical presentations. In fact, because the vast majority of autopsy studies come from teaching hospitals, published autopsy series may be enriched for atypical cases.”

Trends in massage therapy

Massage therapy has some useful applications. It is not inherently pseudoscientific. But like medicine, education and practice in the field have seen considerable contamination by pseudoscience and fraud. The American Medical Massage Association (AMMA) is concerned and has taken a stand against such practices.

Recent data on massage therapy practice patterns published in BMC Complementary and Alternative Medicine would seem to validate the concerns of the AMMA. Surveys conducted in Connecticut and Washington reveal the following respective percentages of massage therapists using questionable methods:

Applied kinesiology 2%, 5.8%

Craniosacral therapy 15.3%, 15.1%

Energy work 24.9%, 17.2%

Oriental bodywork 16.6%, 8.6%

Reflexology 15.0%, 15.4%


This paper provides us with new and confirmatory evidence to support Stephen Barrett’s previous assertion that quackery is pervasive in the field.

Here’s an account of one massage student’s experience.

Cryoglobulinemic vasculitis

Cryoglobulinemic vasculitis is due to hepatitis C in the majority of cases. This review (Current Opinion in Rheumatology) covers many of the points I referenced here.

Best practices in hip fracture care

Hospitalists are often involved in the co management of patients with hip fracture. Published in the November issue of the Journal of General Internal Medicine, (linked via Medscape) this systematic review looked at multiple practices in the perioperative care of hip fracture patients. Specialty mattresses to prevent pressure ulcers, regional anesthesia, DVT prophylaxis, antibiotic prophylaxis, replacing continuous urinary catheters with intermittent catheterization, and epidural analgesia are supported by high level studies. Performance of surgery within 24 hours is also associated with better outcomes although there are no level 1 studies.

Somewhat surprisingly, several popular interventions are not supported by evidence. These include traction, postoperative drains and the use of multidisciplinary teams.

Monday, February 20, 2006

Did UCLA accept money from Herbalife?

Apparently so. The Mark Hughes Cellular and Molecular Nutrition Laboratory, a division of the Center for Human Nutrition, UCLA David Geffin School of Medicine, is named for Herbalife’s founder. UCLA professor of medicine and public health David Heber, M.D. PhD, F.A.C.P., F.A.C.N lent his good name to the company by assuming the chair of Herbalife’s Scientific Advisory Board at about the same time Herbalife donated $3 million to the UCLA center according to this report from Forbes.com. It also seemed to dovetail with the promotion of Herber’s book The L.A. Shape Diet which, according to the Forbes piece, recommends one of Herbalife’s signature products. A win-win situation.

The UCLA center’s nutrition syllabus appears to be a mix of good and bad information. Examples of dubious claims include: a “suggestion” that vitamin E be supplemented in doses of up to 400 IU/day (despite lack of evidence of benefit as assessed in multiple studies and a suggestion of increased risk for heart failure in the HOPE trial); the claim that vitamin C lowers cardiovascular risk; statements that vitamins B12 and B6 and folic acid lower homocysteine levels in patients with cardiovascular disease (they may in certain patients, but the statement is deceptive in that recent evidence contraindicates routine supplementation in patients with cardiovascular disease); and the nebulous claim that echinacea boosts the immune system.

Here’s a critical expose on Herbalife from MLMwatch. This Wikipedia article profiles the history of Herbalife and its multilevel marketing practices.

Candida in the respiratory tract

We knew that Candida recovered from the respiratory tract generally meant colonization and not infection. Now there’s evidence that Candida respiratory tract colonization is a marker of risk for bacterial pneumonia in patients on mechanical ventilation. The strongest association is with Pseudomonas. The study was reported in Chest January 2006.

Friday, February 17, 2006

The granddaddy of Atrovent and Spiriva

The nineteenth and early twentieth century predecessor of these inhaled drugs for COPD was Dr. Schiffmann’s Asthmador. It worked because of its anticholinergic properties residing in the active ingredient belladonna. Like Atrovent and Spiriva it blocked muscarinic receptors in the bronchial tree, resulting in bronchodilation.

It’s certainly more “natural” than Atrovent and Spiriva. I suspect the NCCAM would be subjecting it to the rigors of evidence based medicine were it not for a particular disadvantage---the product had to be smoked in a pipe or as a cigarette---a bit of a problem for folks who use supplemental oxygen.