In today's conversation about health care reform evidence based medicine (sometimes referred to by popular synonyms such as “best practice” or “what works versus what doesn't work”) is a hot topic. Politicians and policy experts believe doctors' adherence to this ideal is poor. Some advocate for policy measures designed to improve on this situation. Such thinking is based on the faulty premise that adherence to EBM can be measured. Experts cite guideline usage or, worse yet, performance metrics as measurable processes to assess EBM adherence.
Such thinking is profoundly simplistic and naïve.
EBM adherence cannot be measured. Why? The answer is to be found in the definition of EBM as put forth by its founders. They wrote it here. David Sackett said it again here. Read and listen carefully. EBM has three key elements. If any of these three is missing, it's not EBM:
The individual patient
The patient's unique attributes, biological, social, psychological. This includes attitudes, preferences and external circumstances.
Individual clinical expertise
That means the expertise, in diagnosis and treatment, of the individual doc who's delivering the care.
The best external evidence
The first two elements are not measurable. The third element seems measurable in concept but in actual practice is inscrutably hard. Sometimes it's elusive. Guidelines and performance measures are not valid surrogates for best external evidence.
It's way, way more complicated.
Tuesday, January 18, 2011
More on not so benign early repolarization
Recall that I blogged on this topic here. Recently Clinical Correlations posted this discussion. It appears that early repolarization changes in the inferior leads carry the highest risk of sudden cardiac death. The association between cardiac death and anterolateral lead early repolarization is weaker. There is no consensus or guideline as to how to manage asymptomatic individuals with the inferior lead early repolarization pattern.
Monday, January 17, 2011
Who's your employer?
Here's an interesting quote appearing at the bottom of a post from Life in the Fast Lane:
Dr. Meador is a Professor of Medicine at Vanderbilt University. I'm not sure but I suspect it came from this book which he wrote years ago. Even more relevant today than it was back then!
“You are the patient’s advocate. You work for no one else.”
Clifton K. Meador
Dr. Meador is a Professor of Medicine at Vanderbilt University. I'm not sure but I suspect it came from this book which he wrote years ago. Even more relevant today than it was back then!
Non-guideline based ICD implantation
---occurred at a rate of about 25% in this study. Deviations had to do largely with timing: not waiting as long post MI as the guidelines recommend, and not waiting to see if patients still met criteria after a period of optimal medical therapy.
Friday, January 14, 2011
Can we prevent ventilator associated pneumonia?
Ventilator associated pneumonia has been characterized by some policy experts as a “never event.” But despite the popularity of “VAP bundles” their effectiveness in preventing ventilator associated pneumonia is not clear. New data from a study in Clinical Infectious Diseases may shed some light. The study looked at the ling-term effect of a bundle of eight interventions:
An earlier paper describing the pilot study listed the interventions:
What are the lessons from this and previous studies on VAP? First, although VAP can be reduced, a substantial incidence remains despite aggressive measures. Based on the evidence we have so far there is no warrant for classifying VAP as a medical error or a never event. Second, there are multiple combinations of interventions which could be bundled. Since evidence for individual interventions is limited, the optimal bundle is not known.
Results. Baseline and intervention VAP rates were 22.6 and 13.1 total VAP episodes over total mechanical ventilation duration per 1000 ventilation-days, respectively, and 26.1 and 14.9 first VAP episodes over mechanical ventilation duration at VAP or hospital discharge per 1000 procedure-days, respectively (P less than .001). VAP rates decreased by 43% in both statistical analyses and remained significant after adjustment for confounders (Cox adjusted hazard ratio, 0.58; 95% confidence interval, 0.46–0.72; P less than .001). Daily VAP hazard rates on ventilation days 5, 10, and 15 were 2.6%, 3.5%, and 3.4%, respectively, during the baseline period and 1.4%, 2.3%, and 2%, respectively, during the intervention period.
Conclusion. Our preventive program produced sustained VAP rate decreases in the long term. However, VAP rates remained substantial despite high compliance with preventive measures, suggesting that eliminating VAP in the intensive care unit may be an unrealistic goal.
An earlier paper describing the pilot study listed the interventions:
1) comply with hand-hygiene; 2) comply with correct glove-and-gown use; 3) maintain adequate endotracheal cuff pressure; 4) ensure bed backrest elevation less than30° (in the absence of medical contraindication); 5) avoid ventilator-circuit disconnection and perform tracheal aspiration only when necessary; 6) provide good oral hygiene; 7) use an orogastric rather than a nasogastric tube; and 8) avoid gastric overdistension.
What are the lessons from this and previous studies on VAP? First, although VAP can be reduced, a substantial incidence remains despite aggressive measures. Based on the evidence we have so far there is no warrant for classifying VAP as a medical error or a never event. Second, there are multiple combinations of interventions which could be bundled. Since evidence for individual interventions is limited, the optimal bundle is not known.
Thursday, January 13, 2011
What is the effectiveness of the AED in hospitalized patients?
A recent study in JAMA found:
Results Of 11 695 patients, 9616 (82.2%) had nonshockable rhythms (asystole and pulseless electrical activity) and 2079 (17.8%) had shockable rhythms (ventricular fibrillation and pulseless ventricular tachycardia). AEDs were used in 4515 patients (38.6%). Overall, 2117 patients (18.1%) survived to hospital discharge. Within the entire study population, AED use was associated with a lower rate of survival after in-hospital cardiac arrest compared with no AED use (16.3% vs 19.3%; adjusted rate ratio [RR], 0.85; 95% confidence interval [CI], 0.78-0.92; P less than .001).
This result was driven by patients with non-shockable rhythms. For patients with shockable rhythms there was no difference between AED and non-AED use.
An editorial in the same issue cited prior research with similar results and also noted studies showing more and longer interruptions of compressions when the AED is used as opposed to a manual defibrillator and concluded:
As the authors suggest, it appears that routine AED use cannot be recommended in the in-hospital setting...
Wednesday, January 12, 2011
Time to take the American Medical Student Association (AMSA) to task again
I've blogged many times about the AMSA and its promotion of quackery in medical education. I did so with the thought that the best way I could fight quackademic medicine was to expose it. The extreme woo promoted by AMSA made great fodder for ridicule with little elaboration or work required on my part. It pretty well spoke for itself. I gave it a rest a year or so ago though because I thought I had covered most everything and, after they redesigned their web site the woo became much harder to find. They've either toned it down or buried it deep, deep within their site, I thought. Whatever the case I even wondered if I deserved a little credit for AMSA's woo assuming a lower profile.
After reading Orac's recent update and doing a little digging of my own it turns out that AMSA's still pushing the same old woo; they've just adopted a smoother approach and made it a little more palatable. I thought this would be a good time to post my own update.
First a look at Orac's post. It was prompted by AMSA's upcoming International Integrative Medicine Day (the link is from last year's event). Here's a sample from this year's event:
During the Happy Hour, clinical services to be offered include: Acupuncture, Massage, Chiropractic, Energy Healing, and more.
Classes from 4:15 - 11PM include Ambient Music, Yoga, Meditation and Qi Gong, Community Drumming for Wellness, and Salsa Class & Dancing.
This page documents AMSA's role as a partner in the event, alongside a virtual parade of stars of woo.
Now for a recap on some of the material I've posted before and what I dug up today. It seems that the promotion of woo on the AMSA web site is organized around four campaigns: ICAM, EDCAM, HUMED (I'll explain about those three in a moment) and, more recently, a strong and rising interest in naturopathic medicine.
ICAM stands for AMSA's initiative for integrative, complementary and alternative medicine. In its present form it's basically a repository for various woo promoting documents and links. There you'll find, for example, the CAM Pocket Handbook. It contains promotional, credulous statements about acupuncture, Ayurvedic Medicine and, yes, that woo of all woo, homeopathy, describing it as “very cost effective over the long term.” Polarity therapy, Reiki, reflexology get similar credulous treatment.
HUMED stands for humanistic medicine. The old HUMED page redirects here. A current focus seems to be student wellness and self care but again, it's another repository of woo. For example, there's the Complementary Therapies Primer which contains the same old woo, including a particularly non-critical view of reflexology, along with several types of woo I had never heard of. It also claims that large doses of vitamin E are useful in Parkinson's disease. You'll also find the claim that fasting eliminates pesticides and other toxins from the body. Finally, it says chelation therapy (no, I'm not making this up) is beneficial for arthritis, scleroderma, lupus and spider bites.
EDCAM, which stands for Educational Development for Complementary and Alternative Medicine, is a completed project in which the AMSA Foundation, with funding from the NIH and the NCCAM, introduced and developed CAM, including a lot of woo, in the curricula of 14 medical schools. In an article published in the journal Academic Medicine (which none of the aforementioned organizations will likely want you to read) reviewers from Baylor found the teaching material to be devoid of supporting evidence and concluded:
By tolerating this situation, health professions schools are not meeting their educational and ethical obligations to learners, patients, or society.
I blogged about the whole thing here.
Finally there's the Naturopathic Medicine page, which says that the AMSA aims for collaboration with naturopathic medical students. This page has lots of dubious links and a recommended reading list of promotional material for all sorts of woo. I won't go to the trouble of fisking it here. This post is getting long and the list speaks for itself.
In my blogging career I've gotten into many discussions about the rise of quackademic medicine. A common theme is speculation as to why, and it seems inscrutably hard to determine for some. Sure, the money behind it is one element. But after following quackademic medicine closely for several years (although it was a few years later that I coined the term, my first post about it was here) I am of the opinion that the AMSA has been a major driver, perhaps the major driver of this trend.
Eleanor Roosevelt's tuberculosis
This Medscape article chronicles Eleanor Roosevelt's illness. Eleanor Roosevelt carried a diagnosis of aplastic anemia for two years, for which she received multiple transfusions and was given prednisone. It was not until two weeks before her death that her final bone marrow specimen grew out tuberculosis.
When I was a medical student the story was circulating around that Eleanor Roosevelt had died of miliary Tb that had long been misdiagnosed as aplastic anemia, but I didn't know if it was really true. The Medscape piece, which draws on information from Roosevelt's medical record, is the best account I've found.
This was a popular topic when I was a medical student. One of our most esteemed and feared Internal Medicine mentors, Thomas E. Brittingham, always encouraged skepticism toward accepting any diagnosis of an incurable disease, particularly if an infectious cause could be sought. He was particularly negative about diagnosing patients with idiopathic inflammatory diseases and treating them with immunosuppressives and was fond of presenting patients long diagnosed with such diseases as systemic lupus, Wegener's granulomatosis or inflammatory bowel disease and ultimately discovered to have tuberculosis or a fungal disease.
When I was a medical student the story was circulating around that Eleanor Roosevelt had died of miliary Tb that had long been misdiagnosed as aplastic anemia, but I didn't know if it was really true. The Medscape piece, which draws on information from Roosevelt's medical record, is the best account I've found.
This was a popular topic when I was a medical student. One of our most esteemed and feared Internal Medicine mentors, Thomas E. Brittingham, always encouraged skepticism toward accepting any diagnosis of an incurable disease, particularly if an infectious cause could be sought. He was particularly negative about diagnosing patients with idiopathic inflammatory diseases and treating them with immunosuppressives and was fond of presenting patients long diagnosed with such diseases as systemic lupus, Wegener's granulomatosis or inflammatory bowel disease and ultimately discovered to have tuberculosis or a fungal disease.
Tuesday, January 11, 2011
JAMA commentary proposes adding emotion and passion to scientific articles
Some medical journals such as JAMA and the Annals of Internal Medicine occasionally publish emotional articles that convey the human side of medicine. Many journals, NEJM notable among them, also weigh in on political issues. Appropriately, the emotional and political content is clearly compartmentalized from the scientific content. A commentary writer in the December 8 issue of JAMA seems to think that may not be a good thing:
Apparently the author, Robert H. Brook, MD, of the Rand Corporation, thinks the dispassionate language of scientific papers is too dry to be useful. Earlier in the paper he wrote:
That's what Dr. Brook thinks is wrong with scientific articles. What nonsense. Steve Milloy, in his book Junk Science Judo, wrote, on page 46:
Dr. Brook seems to start with a faulty premise: that the purpose of a research article is to persuade. Wrong. Persuasion is an art which almost by definition introduces fallacies. That's what Aristotle laid out in his textbook on Rhetoric. He described the three elements of persuasion: ethos, pathos and logos. Scientific papers confine themselves to logos. Bring in the other two elements and you introduce all sorts of emotionally driven fallacies such as appeals to fear, passion and belief. More than that, allowing an author's emotions and passions in a scientific paper would deliberately permit and even introduce bias.
It's true that doctors need to be persuaded to incorporate the best evidence into practice. But please, not in original scientific papers. There are other appropriate places and methods to accomplish that. Imagine if clinical investigators passionately spun the results right in their own research articles! It would make a joke of scientific journals.
As an aside I note this little gem of an observation Brook makes midway through the paper:
Here Brook comes dangerously close to saying that social media has dumbed down science education for a whole generation of students! Could it be? I'm not sayin'. U r free 2 read n 2 that what u want 2 LOL.
What if science were presented in the same passionate, emotional style as in those accounts of personal experiences that moved the physician who wrote them? Instead of requiring a science article to have the standard introductory, methods, results, and discussion sections with a certain number of words and a certain number of tables, science articles should perhaps include cartoons, pictures, or emotional images that contain meaning and require the use of both the right and left brain. Perhaps permitting the personal would not degrade the scientific process but rather increase the likelihood that the information contained in the journals would actually be read, absorbed, and used.
Apparently the author, Robert H. Brook, MD, of the Rand Corporation, thinks the dispassionate language of scientific papers is too dry to be useful. Earlier in the paper he wrote:
...scientific articles are written in a manner that, in many instances, adopts a bland, somnolent tone. The language has no passion, conveys no emotion. The words stimulate no visual image. Physicians have been taught to present their science in what is called a “flat manner”: let the facts speak for themselves.
That's what Dr. Brook thinks is wrong with scientific articles. What nonsense. Steve Milloy, in his book Junk Science Judo, wrote, on page 46:
...keep the slow, steady ho-hum scientific method in mind. Boring? Sure. Tedious? You betcha. Slow and deliberative? Be grateful.
Dr. Brook seems to start with a faulty premise: that the purpose of a research article is to persuade. Wrong. Persuasion is an art which almost by definition introduces fallacies. That's what Aristotle laid out in his textbook on Rhetoric. He described the three elements of persuasion: ethos, pathos and logos. Scientific papers confine themselves to logos. Bring in the other two elements and you introduce all sorts of emotionally driven fallacies such as appeals to fear, passion and belief. More than that, allowing an author's emotions and passions in a scientific paper would deliberately permit and even introduce bias.
It's true that doctors need to be persuaded to incorporate the best evidence into practice. But please, not in original scientific papers. There are other appropriate places and methods to accomplish that. Imagine if clinical investigators passionately spun the results right in their own research articles! It would make a joke of scientific journals.
As an aside I note this little gem of an observation Brook makes midway through the paper:
However, the world of communication has changed. Today, the Internet, Facebook, LinkedIn, and all sorts of connected devices allow humans to immediately share photographs, emotions, thoughts, and passions. It is difficult to imagine a young physician growing up in this communication environment, trying to focus his or her brain on science studies that seem to be written in a language as foreign as medieval English would be to modern inhabitants of the British Isles.
Here Brook comes dangerously close to saying that social media has dumbed down science education for a whole generation of students! Could it be? I'm not sayin'. U r free 2 read n 2 that what u want 2 LOL.
Rescue therapy for refractory hypoxemia in ARDS
I recently highlighted this as one of the top issues in hospital medicine for last year. Although I missed this review in JAMA from December 8 when preparing that post, many of the same points were made. The review is in a Johns Hopkins Grand Rounds format and the full text (which is unfortunately behind access control) is worth reading in its entirety. It provides a nice overview of ARDS.
ARDS is hypoxemic respiratory failure. Despite this, as is pointed out in the article, only a small minority, on the order of 10-15%, of the mortality is attributable to refractory hypoxemia. The remainder is due to failure of other organs.
General supportive care is the mainstay of management of ARDS with only one specific modality known from research evidence to decrease mortality: low tidal volume ventilation. Multiple other modalities which in studies have not been shown to decrease overall mortality but can improve oxygenation are considered rescue therapies, examples of which are prone positioning, heavy sedation with paralysis, high frequency modalities, high peep and recruitment maneuvers. Rescue therapies, while not “evidence based” in the strict sense, may offer the patient's only chance for survival in desperate situations involving refractory hypoxemia.
Which rescue therapies to implement depend in part on local expertise. Provision of rescue therapy will require some preparation, particularly if the patient requires transfer to another facility. This underscores the importance of early severity assessment which facilitates planning for possible rescue therapy.
ARDS is hypoxemic respiratory failure. Despite this, as is pointed out in the article, only a small minority, on the order of 10-15%, of the mortality is attributable to refractory hypoxemia. The remainder is due to failure of other organs.
General supportive care is the mainstay of management of ARDS with only one specific modality known from research evidence to decrease mortality: low tidal volume ventilation. Multiple other modalities which in studies have not been shown to decrease overall mortality but can improve oxygenation are considered rescue therapies, examples of which are prone positioning, heavy sedation with paralysis, high frequency modalities, high peep and recruitment maneuvers. Rescue therapies, while not “evidence based” in the strict sense, may offer the patient's only chance for survival in desperate situations involving refractory hypoxemia.
Which rescue therapies to implement depend in part on local expertise. Provision of rescue therapy will require some preparation, particularly if the patient requires transfer to another facility. This underscores the importance of early severity assessment which facilitates planning for possible rescue therapy.
The decline effect
---refers to a waning of the magnitude of positive research findings over time. In other words while initial research may lead to a slam dunk conclusion subsequent attempts to replicate it, though sometimes positive, are often less robust. Other times, of course, they don't stand up at all. Such was the topic of a recent piece in The New Yorker.
Aside from a few flaws in the article (its implication that early popularity of HRT was bolstered by randomized controlled trials, credulity towards acupuncture and a statement that research on cardiac stents suffered from the decline effect) it did a fair job of illustrating some of the booby traps of conducting and reporting research.
The article explored several explanations for the effect including regression to the mean. No single one is adequate. There are probably many contributing factors. Initial research findings may be more likely to suffer from investigator and publication bias than those of subsequent investigations, which may bring more skepticism to the picture. Sometimes initial studies have design issues that make them unsuitable for generalization or widespread change in practice such as small size or anomalies in the sample that was studied. Early studies on glycemic control in hospitalized patients and perioperative beta blockers come to mind.
So do we throw evidence based medicine (EBM) and science based medicine (SBM) out the window? Not at all. This is just a reminder that though some science is for practical purposes settled, much of it is tentative. That's why EBM regards the most current evidence as an important attribute of best evidence.
Related content at DB's Medical Rants.
Aside from a few flaws in the article (its implication that early popularity of HRT was bolstered by randomized controlled trials, credulity towards acupuncture and a statement that research on cardiac stents suffered from the decline effect) it did a fair job of illustrating some of the booby traps of conducting and reporting research.
The article explored several explanations for the effect including regression to the mean. No single one is adequate. There are probably many contributing factors. Initial research findings may be more likely to suffer from investigator and publication bias than those of subsequent investigations, which may bring more skepticism to the picture. Sometimes initial studies have design issues that make them unsuitable for generalization or widespread change in practice such as small size or anomalies in the sample that was studied. Early studies on glycemic control in hospitalized patients and perioperative beta blockers come to mind.
So do we throw evidence based medicine (EBM) and science based medicine (SBM) out the window? Not at all. This is just a reminder that though some science is for practical purposes settled, much of it is tentative. That's why EBM regards the most current evidence as an important attribute of best evidence.
Related content at DB's Medical Rants.
Monday, January 10, 2011
Megyn Kelly handles Sheriff Dupnick
---and exposes his foolishness. Deferentially and with respect.
OK, back to regular blogging, punctuated if the need arises by updates on this topic.
OK, back to regular blogging, punctuated if the need arises by updates on this topic.
After Arizona shootings the political vultures swoop
I've tried to make it a rule to confine political blogging to issues of health policy. Today I'm breaking that rule. I don't want to, I have to. I simply can't contain my outrage. So let's start with this piece from NRO:
And rush they did. Almost immediately after it happened Paul Krugman, admitting he didn't know if the shooting was political, blamed the Right anyway.
Upon first learning of this tragic shooting I suspected something like this would happen but I had no idea of the degree of political opportunism that would follow. Disgusting.
Very few Americans are fans of both The Communist Manifesto and Mein Kamp, as the Tucson killer, 22-year-old Jared Lee Loughner, apparently was. Fewer still post on the Internet fears about “brain washing,” “mind control,” and “conscience dreaming”; have a long record of public disruption and aberrant behavior; were expelled from community college; or were summarily rejected for military service.
No matter. Almost immediately following Loughner’s cowardly murdering of six and wounding of 14 including Rep. Gabrielle Giffords, pundits and some public figures rushed to locate his rampage, together with his paranoid rantings about government control, within the larger landscape of right-wing politics — especially the rhetoric of the Tea Party and Sarah Palin.
And rush they did. Almost immediately after it happened Paul Krugman, admitting he didn't know if the shooting was political, blamed the Right anyway.
Upon first learning of this tragic shooting I suspected something like this would happen but I had no idea of the degree of political opportunism that would follow. Disgusting.
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