Science-Based Medicine

I’ll begin with the possibly shocking admission that I’m a strong supporter of the collection of ideas and techniques known as evidence-based medicine (EBM). I’m even the current President of the Evidence-Based Veterinary Medicine Association (EBVMA). This may seem a bit heretical in this context, since EBM  takes a lot of heat in this blog. But as Dr. Atwood has said, “we at SBM are in total agreement…that EBM “should not be without consideration of prior probability, laws of physics, or plain common sense,” and that SBM and EBM should not only be mutually inclusive, they should be synonymous.” So I have hope that by emphasizing the distinction between SBM and EBM and the limitations of EBM, we can engender the kind of changes in approach needed to address those limitations and eliminate the need for the distinction. One way of doing this is to critically evaluate the misuses of EBM in support of alternative therapies.

One of the highest levels of evidence in the hierarchy of evidence-based medicine is the systematic review. Unlike narrative reviews, in which an author selects those studies they consider relevant and then summarizes what they think the studies mean, which is a process subject to a high risk of bias, a systematic review identifies randomized controlled clinical trials according to an explicit and objective set of criteria established ahead of time. Predetermined criteria are also used to grade the studies evaluated by quality so any relationship between how well studies are conducted and the results can be identified. Done well, a systematic review gives a good sense of the balance of the evidence for a specific medical question.

Unfortunately, poorly done systematic reviews can create an strong but inaccurate impression that there is high-level, high-quality evidence in favor of a hypothesis when there really isn’t. Reviews of acupuncture research illustrate this quite well.

Continue Reading »

Your health insurance plan probably covers anti-inflammatory drugs. But does it cover acupuncture treatments? Should it? Which health services deliver good value for money? Lest you think the debate is limited to the United States (which is an outlier when it comes to health spending), even countries with publicly-run healthcare systems are scrutinizing spending. Devoting dollars to one area (say, hospitals) is effectively a decision not to spend on something else, (perhaps public health programs). All systems, be they public or private, allocate funds in ways to spend money in the most efficient way possible. Thoughtful decisions require a consideration of both benefits and costs.

One of the consistent positions put forward by contributors to this blog is that all health interventions should be evaluated based on the same evidence standard. From this perspective, there is no distinct basket of products and services which are labelled “alternative”, “complementary” or more recently “integrative”. There are only treatments and interventions which have been evaluated to be effective, and those that have not. The idea that these two categories should both be considered valid approaches is a testament to promoters of complementary and alternative medicine (CAM), who, unable to meet the scientific standard, have argued (largely successfully) for different standards and special consideration — be it product regulation (e.g., supplements) or practitioner regulation.

Yet promoters of CAM seek the imprimatur of legitimacy conferred by the tools of science. And in an environment of economic restraint in health spending, they further recognize that showing economic value of CAM is important. Consequently they use the tools of economics to argue a perspective, rather than answer a question. And that’s the case with a recent paper I noticed was being touted by alternative medicine practitioners. Entitled, Are complementary therapies and integrative care cost-effective? A systematic review of economic evaluations, it attempts to summarize economic evaluations conducted on CAM treatments. Why a systematic review? One of the more effective tools for evaluating health outcomes, a systematic review seeks to analyze all published (and unpublished) information on a focused question, using a standardized, transparent approach to evidence analysis. When done well, systematic reviews can sift through thousands of clinical trials to answer focused questions in ways that are less biased than cherry-picking individual studies. The Cochrane Review’s systematic reviews form one of the more respected sources of objective information (with some caveats) on the efficacy of different health interventions. So there’s been interest in applying the techniques of systematic reviews to questions of economics, where both costs and effects must be measured. Economic evaluations at their core seek to measure the “bang for the buck” of different health interventions. The most accurate economic analyses are built into prospective clinical trials. These studies collect real-world costs and patient consequences, and then allow an accurate evaluation of value-for-money. These types of analyses are rare, however. Most economic evaluations involve modelling (a little to a lot) where health effects and related costs are estimated, to arrive at a calculation of value. Then there’s a discussion of whether that value calculation is “cost-effective”. It’s little wonder that many health professionals look suspiciously at economic analyses: the models are complicated and involve so many variables with subjective inputs that it can be difficult to sort out what the real effects are. Not surprisingly, most economic analyses suggest treatments are cost-effective. Before diving into the study, let’s consider the approach:

Continue Reading »

It is estimated that 5% of people living in Sub-Saharan Africa are infected with HIV – that’s 22.5 million people. Infection rates vary wildly from country to country, with Swaziland having the highest rate at 25.9%. Gambia is below average, at 2% or 18 thousand people, but still has a serious HIV problem, and now finds themselves at the center of the HIV controversy in Africa.

This epidemic has been magnified by unfortunate realities on the ground. Africa has an insufficient public health and medical infrastructure to deal with the massive challenge such an epidemic presents. This has led the World Health Organization to contemplate partnering with local traditional healers, to make them into an extension of the effort to bring modern medical treatment to the HIV-infected in Africa. This desperate strategy is fraught with problems, not the least of which is that most traditional healers have had no prior contact with science-based medicine.

Former South African president Thabo Mbeki seriously set back his country’s HIV efforts by embracing crank HIV denial. Coupled with his denialism was efforts by Health Minister Manto Tshabalala-Msimang to use traditional medicines to treat HIV/AIDS. This combination resulted in restrictions on the distribution of anti-retoviral drugs in South Africa that is estimated to have cost hundreds of thousands of lives.

Continue Reading »

The American Academy of Family Physicians journal American Family Physician (AFP) has a feature called Journal Club that I’ve mentioned before.  Three physicians examine a published article, critique it, discuss whether to believe it or not, and put it into perspective. In the September 15 issue  the journal club analyzed an article that critiqued the process for developing clinical practice guidelines. It discussed how two reputable organizations, the United States Preventive Services Task Force (USPSTF) and the American Academy of Pediatrics (AAP) looked at the same evidence on lipid screening in children and came to completely different conclusions and recommendations.

The AAP recommends testing children ages 2-10 for hyperlipidemia if they have risk factors for cardiovascular disease or a positive family history. The USPSTF determined that there was insufficient evidence to recommend routine screening. How can a doctor decide which recommendation to follow? Continue Reading »

As I mentioned recently, as hard as it is to believe, this blog is rapidly approaching the end of its fifth year of existence. Our first post was delivered to the anxiously waiting world on January 1, 2008; so thus upcoming January 1 will represent our fifth anniversary. In the blogging world, that’s almost the equivalent of a fiftieth anniversary, given how fast most blogs turn over. Something that is even more satisfying than mere longevity is that we really have found a niche in the medical blogosphere to the point where we’ve become quite influential. People notice us. Our targets notice it when we discuss them. Sometimes even the press notices us. This is all a very good thing.

Unfortunately, even though we’ve been at this for just shy of five years, there are still topics we haven’t covered, or at least haven’t covered in sufficient depth. The topic of my post today is one of the latter topics. We’ve mentioned it before; we’ve alluded to it before (for instance when discussing the antivaccine website Medical Voices and the Ayn Rand-worshiping Association of American Physicians and Surgeons; but there hasn’t been a post dedicated to this particular topic. I find this particularly odd because it was one a piece of misinformation promoted by elements of the antivaccine movement that truly shocked and disgusted me. Before I learned of this particular myth, I was surprised to learn that there are really people who think that vaccines are dangerous and cause autism, but I viewed it as being of a piece of a lot of other quackery I was discovering at the time.

Way back in the day, when I first encountered antivaccine views in that wretched Usenet swamp of pseudoscience, antiscience, and quackery known as misc.health.alternative (m.h.a.), there was one particular antivaccine lie that disturbed me more than just about any other. As I mentioned, it wasn’t the claim that vaccines cause autism, which is more or less the central dogma of the antivaccine movement. Even ten years ago, before the series of studies that have been released since then that fail to find a hint of a whiff of causation between vaccines and autism, that wasn’t a particularly difficult myth to refute. Indeed, given newer studies, refuting that myth has only gotten easier over the years. Emblematic of how far into the depths that particular myth has been pummeled, I know it’s gotten pretty easy when even the mainstream media start to accept that the claim that vaccines cause autism is a myth and report matter-of-factly on issues such as Andrew Wakefield’s fraud and don’t give nearly as much copious and prominent media time to the likes of Jenny McCarthy. Let’s just put it this way. When the hosts of a “morning zoo”-type radio show in Salt Lake City pummel the latest antivaccine celebrity to make a fool of himself, Rob Schneider, you know that, from an informational standpoint at least, the tide appears to have turned from several years ago, when the media took this myth a lot more seriously. That’s not to say that we don’t still have a problem. After all, “philosophical” exemption rates are going up based on a lot of this sort of misinformation, but at least the media are less insistent on “telling both sides” of a science story that doesn’t really have two sides.
Continue Reading »

David Gorski recently pointed out that Science Based Medicine is going on five years. Amazing. That there would be so much to write about day after day comes as a surprise to me. Somehow I vaguely thought that ‘controversies’ would be resolved. Pick a SCAM, contrast the SCAM with reality as best we understand it, and, once the SCAM was found wanting, it would be abandoned. Why would rational, thoughtful people persist in the pursuit of irrational behavior, contradicted by the universe?

Ha. More the fool me. I would never have guessed that these SCAMs are harder to kill than Dracula (at least one version of Dracula). Stake them and back they come*.

I have tried to avoid repeating repeating information found in prior posts by myself and others, in part because I am lazy and in part because, well, I have said it before. Just look it up. I have come to realize (all too slowly) that each blog entry should be  self contained and that much of the old material is lost in the corn maze (an punning homophone) that is WordPress. Reading my second favorite computer reinforces the realization that each post often needs to be an island universe, complete in itself.

Continue Reading »

Supporters of science-based medicine have expressed concern over this provision in the Patient Protection and Affordable Care Act (“Obamacare,” or the “ACA.”):

SEC. 2706. NON-DISCRIMINATION IN HEALTH CARE.

(a) PROVIDERS.—A group health plan and a health insurance issuer offering group or individual health insurance coverage shall not discriminate with respect to participation under the plan or coverage against any health care provider who is acting within the scope of that provider’s license or certification under applicable State law. This section shall not require that a group health plan or health insurance issuer contract with any health care provider willing to abide by the terms and conditions for participation established by the plan or issuer. Nothing in this section shall be construed as preventing a group health plan, a health insurance issuer, or the Secretary from establishing varying reimbursement rates based on quality or performance measures.

Section 2706 (now codified as 42 U.S.C. Sec. 300gg-5) goes into effect in 2014 and covers virtually all individual and group insurance market policies, although it is not clear whether it will apply to existing policies “grandfathered” in 2010 by the ACA.

Section 2706 was not part of the U.S House of Representatives version of the ACA but was included in the Senate version (which ultimately passed) under the guidance of (surprise!) Sen. Tom Harkin (D-Iowa). It was heavily lobbied by the American Chiropractic Association and other “CAM” providers, as well as some “conventional” providers like nurse anesthetists and optometrists. The legislative history (reports, committee minutes, floor debates and the like which precede a vote on a bill) indicates it was specifically included to prevent discrimination against CAM providers.  This is of obvious concern to anyone who supports science-based, or for that matter evidence-based, medicine, as there is nothing to indicate that scientific plausibility or evidence (or the lack thereof) actually affects CAM practices. It should also concern insurers and those who pay for insurance (employers and individuals) to the extent it might require payment for CAM treatments, as ineffective treatments will negatively affect their bottom line. The U.S. Departments of Health and Human Services (HHS) and Labor and the Treasury Department, which are charged with issuing regulations implementing the ACA, have not yet promulgated regulations for Section 2706. The American Medical Association House of Delegates has already passed a resolution seeking its repeal.

Continue Reading »

A recent survey about patient attitudes and desires with regard to health care demonstrate that respect for scientific evidence is still the dominant factor in preferring treatments. (Full study) This is good news, although the numbers could be better.

Researchers asked subjects what factors were important in determining which treatments they would prefer, the scientific evidence, the experience of the clinician, or their own personal preferences. Not surprisingly, most subjects wanted it all, agreeing that all three are important. Scientific evidence, however, scored the highest with 71% rating it as very important (and over 90% as important or very important). Clinical expertise had 61% strongly supported and personal preference, 57%.

Further, patients wanted their doctors to talk to them about the evidence. The phrase they felt had the most impact on their decision to accept a treatment was, “What is proven to work best.”

All of this matches my personal experience as a clinician. At least for the self-selective population of patients who seek out a university physician, patients tend to find recommendations based upon published evidence compelling, and greatly appreciate when I take the time to tell them about the evidence, even if it goes against their initial interests.

Continue Reading »

I intended to read Sam Kean’s new book The Violinist’s Thumb: And Other Lost Tales of Love, War, and Genius as Written by our Genetic Code  just for fun. I was expecting a miscellany of trivia loosely gathered around the theme of DNA. But I found something much more worthwhile that I thought merited a book review to bring it to the attention of our readers. Kean interweaves entertaining stories into a somewhat disjointed but nonetheless valuable history and primer of genetics. The title refers to Paganini, whose DNA created the unusual joint flexibility that facilitated his unprecedented feats of virtuosity on the violin.

Continue Reading »

Over the years, I’ve written a lot about “personalized medicine, mainly in the context of how the breakthroughs in genomic medicine and data pouring in from the Cancer Genome Atlas is providing the raw information necessary for developing truly personalized cancer therapy. The problem, of course, is analyzing it and figuring out how to apply it. Another problem, of course, is developing the necessary targeted drugs to attack the pathways that are identified as being dysregulated in cancer cells. Oh, and there’s that pesky evolution of resistance to antitumor therapies. Indeed, most recently, the Cancer Genome Atlas is bearing fruit in breast cancer (a study that I’ve been meaning to blog about).

One problem with modeling the pathways based on next generation sequencing data and expression profiling is testing whether therapies predicted to work from these analyses actually do work without actually testing potentially toxic drugs on patients. Cell culture is notoriously unreliable as a predictor. However, there is another way that’s intriguing. Unfortunately, as intriguing as it is, it has numerous problems, and, unfortunately, it’s being prematurely marketed to patients. Although I had heard of this technique as a research tool before, I learned about its marketing to patients when I came across an article by Andrew Pollack in the New York Times entitled Seeking Cures, Patients Enlist Mice Stand-Ins. Basically, it’s about a trend in science and among patients to use custom, “personalized’ mouse xenograft models in order to do “personalized” therapy:
Continue Reading »