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What Is Brain Death?

Of course, any story illustrating the issues surrounding brain death is going to be a sad and tragic tale. In December of 2013, Jahi McMath suffered bleeding complications following a tonsillectomy and tissue removal for sleep apnea. This resulted in a cardiac arrest with an apparent prolonged period of lack of blood flow to the brain. While her heart function was brought back, Jahi suffered severe brain anoxia (damage due to lack of oxygen) and was declared brain dead on December 12, 2013.

Jahi’s tragic story is not over, however, because her family refused to accept the diagnosis of brain death. They took legal action to keep the hospital from pulling life support, and eventually worked out a compromise where the family was able to remove Jahi to their own care. At present Jahi is apparently being cared for in an apartment in New Jersey, on a ventilator and fed through a feeding tube.

There is often some confusion as to what brain death actually is. The term is unfortunately often used to refer to a persistent vegetative state or other severe impairment of consciousness, but this is not accurate. Brain death refers to a complete lack of function of the brain, including basic reflexes in the brain stem. There is a specific protocol for declaring a person brain dead, requiring detailed examination by at least two attending physicians to document the complete absence of any brain function. If the slightest pupillary reflex is present, then the patient cannot be declared brain dead. The criteria also include provisions that there are no medications in the person’s system that can suppress neurological function and their core body temperature is sufficiently high (being too cold can also suppress neurological function).

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Posted in: Neuroscience/Mental Health

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Making One’s Own Reality – Food Babe Edition

Vani Hari, aka the "Food Babe".

Vani Hari, the “Food Babe”.

The default mode of human activity is to construct our own internal model of reality based upon our desires, biases, flawed perceptions, memories, and reasoning, and received narratives from the culture in which we live. That model of reality is then reinforced by confirmation bias and jealously defended.

But we also have the capacity to transcend this pathway of least resistance. Philosophy is the discipline of thinking carefully and systematically about ideas to see if they at least are internally consistent. Science is the discipline of systematically and carefully comparing our internal models of reality against objective reality, and then changing those models to suit the evidence.

Everyone engages in a combination of bias, superstition, logic, and evidence-based reason to varying degrees – the question is, to what degree? The goal of science-based medicine is to increase the proportion of science and reason in the mix with respect to the practice of medicine and public health.

There are many forces at work in society, however, that explicitly oppose the role of science because, in my opinion, they find it inconvenient to their internal model of reality or whatever narrative they are selling.

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Posted in: Science and Medicine

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Another Review Finds Homeopathy Worthless

homeopathy T

Just say “NO” to homeopathy. Available at skeptoid.com.

It is long past time to close the door on homeopathy. After thousands of studies, homeopaths are still unable to produce convincing evidence that homeopathy works for any indication. Multiple reviews of the evidence have come to this conclusion, and now we have one more to add to the pile – the Australian National Health and Medical Research Council (NHMRC) just published their report after reviewing the clinical evidence and have concluded that homeopathy doesn’t work for anything.

Homeopathy is a prescientific medical philosophy based upon the fanciful notions that like cures like (which is really an expression of sympathetic magic) and that extreme dilutions of a substance can retain the magical essence of the substance. These ideas were silly two centuries ago when they were invented. The scientific advances we have made since them have only deepened this conclusion. Homeopathy should have been tossed onto the scrap heap of history along with phrenology, humoral theory, mesmerism, and other quaint ideas. Its persistence is testimony to the power of cultural inertia.

Despite the fact that homeopathic potions have essentially zero scientific plausibility (as close to zero as we can get in science), a great deal of resources have been wasted testing homeopathy clinically. The recent NHMRC review identified more than 1,800 studies, of which 225 were of sufficient size and rigor to include in the review. They report:

The review found no good quality, well-designed studies with enough participants to support the idea that homeopathy works better than a placebo, or causes health improvements equal to those of another treatment.

Although some studies did report that homeopathy was effective, the quality of those studies was assessed as being small and/or of poor quality. These studies had either too few participants, poor design, poor conduct and or [sic] reporting to allow reliable conclusions to be drawn on the effectiveness of homeopathy.

According to CEO Professor Warwick Anderson, “All medical treatments and interventions should be underpinned by reliable evidence. NHMRC’s review shows that there is no good quality evidence to support the claim that homeopathy works better than a placebo.”

In 2013 the NHMRC published a review of the clinical evidence for homeopathy, and they broke this down by medical condition. Of the 68 medical conditions they examined, for 7 of them there was no quality evidence from which to draw any conclusions. For 61 of the conditions there was evidence for lack of efficacy – not just a lack of evidence showing that homeopathy works, but evidence showing that homeopathy does not work. (more…)

Posted in: Homeopathy

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Personal Belief Exemptions for Vaccines

vaccinationRates

Click to enlarge

Positive change not only requires a valid argument, it requires political will. My colleagues and I have been pointing out for years that vaccines are safe and effective, and the anti-vaccine movement, which is built largely on misinformation, threatens the public health by eroding herd immunity. These arguments are no more valid today than they were five or ten years ago (except that new scientific evidence continues to support our conclusion).

We also predicted that it will likely take the significant return of vaccine-preventable diseases to muster the political will to effectively push back against the anti-vaccine movement. Parents need to be more afraid of infectious disease than the false fearmongering surrounding vaccines. We, of course, did not want this to happen, we just thought this was a likely scenario.

I did not think, however, that it would be so sudden and dramatic. The Disneyland measles outbreak created an undeniable media and popular backlash against the anti-vaccine movement. Recent evidence for this is the Jimmy Kimmel segment in which he blasted anti-vaxxers and showed a fake PSA in which real doctors express their frustration over vaccine refusers. Anti-vaxxers replied with their usual shrill nonsense, comparing Kimmel’s statements to hate speech and falsely accusing him of attacking autistic children. Kimmel responded with still more ridicule, making a mockery of anti-vaxxer tweets attacking him. Being the butt of late night comedian jokes is a reasonable sign of popular backlash.

Popular opinion, which is turning against vaccine refusers for threatening the public health, translates into political will. In the case of vaccines there is a specific focus for this political will – state laws allowing exemptions from the requirement for children to be up to date on their vaccines in order to attend public school.

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Posted in: Science and Medicine, Vaccines

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Psychology Journal Bans Significance Testing

p-valuesThis is perhaps the first real crack in the wall for the almost-universal use of the null hypothesis significance testing procedure (NHSTP). The journal, Basic and Applied Social Psychology (BASP), has banned the use of NHSTP and related statistical procedures from their journal. They previously had stated that use of these statistical methods was no longer required but can be optional included. Now they have proceeded to a full ban.

The type of analysis being banned is often called a frequentist analysis, and we have been highly critical in the pages of SBM of overreliance on such methods. This is the iconic p-value where <0.05 is generally considered to be statistically significant.

The process of hypothesis testing and rigorous statistical methods for doing so were worked out in the 1920s. Ronald Fisher developed the statistical methods, while Jerzy Neyman and Egon Pearson developed the process of hypothesis testing. They certainly deserve a great deal of credit for their role in crafting modern scientific procedures and making them far more quantitative and rigorous.

However, the p-value was never meant to be the sole measure of whether or not a particular hypothesis is true. Rather it was meant only as a measure of whether or not the data should be taken seriously. Further, the p-value is widely misunderstood. The precise definition is:

The p value is the probability to obtain an effect equal to or more extreme than the one observed presuming the null hypothesis of no effect is true.

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Posted in: Basic Science, Clinical Trials, Science and Medicine

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Reporting Research Misconduct

Perhaps one of the greatest threats to the enterprise of Science-Based Medicine is research fraud and misconduct. Rigorous research methods can be used to minimize the effects of bias, but when those methods themselves are the problem there is no easy fix. Related to this is the need for transparency. When fraud or misconduct is uncovered it erodes confidence in the system because it provokes speculation about how much fraud and misconduct has not been uncovered.

A recent study published in JAMA looks at one aspect of this issue – reporting of misconduct uncovered by the FDA. The good news here is that FDA trials, those that will be used to apply to the FDA for approval of a drug, are carefully monitored and inspected by the FDA. This is an important quality control measure. When the FDA uncovers misconduct it takes steps to correct it. If the misconduct is severe enough then any data that is associated with the poor research practices will be excluded from the trial so as not to taint the results. Even an entire study can be disqualified if necessary.

The problem highlighted by the study is that there is no systematic way for the FDA to communicate its findings through the peer-reviewed literature. Tainted studies, or ones that require a correction or retraction (because the violations were discovered after publication) may therefore persist in the peer-reviewed literature without any indication of the uncovered misconduct.

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Posted in: Science and Medicine

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Significant Ruling Against Conversion Therapy

gay-flag

The standard features of quackery are all there. Proponents of this particular therapy claim that a normal condition is a disease. They make false claims about the cause of this disease. They then charge thousands of dollars for their fake treatment to cure the fake disease, and claim success rates that are not backed by any statistics.

In this case the fake disease is homosexuality, for which there is now a solid consensus that it is a normal variation of human sexuality. The fake treatment is conversion therapy. Recently a New Jersey judge ruled that conversion therapists cannot claim that homosexuality is a disease or disorder. The Southern Poverty Law Center reports:

Superior Court Judge Peter F. Barsio Jr. found that it “is a misrepresentation in violation of [New Jersey’s Consumer Fraud Act], in advertising or selling conversion therapy services, to describe homosexuality, not as being a normal variation of human sexuality, but as being a mental illness, disease, disorder, or equivalent thereof.”

Further:

The judge also ruled that [New Jersey conversion therapy provider Jews Offering New Alternatives for Healing (JONAH)] is in violation of the Consumer Fraud Act if it offers specific success statistics for its services when “client outcomes are not tracked and no records of client outcomes are maintained” because “there is no factual basis for calculating such statistics.”

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Posted in: Legal, Medical Ethics

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How Not to Treat Migraine

Image credit: Wellcome Images, Wellcome Library, London, via Wikimedia Commons.

Image credit: Wellcome Images, Wellcome Library, London, via Wikimedia Commons.

Last week I gave a quick overview of standard treatment options for migraine, a severe form of recurrent headaches. As promised, this week I will address some common treatments for migraine that I don’t think are supported by the evidence.

Acupuncture

Acupuncture is the CAM modality that, it seems to me, has infiltrated the furthest into mainstream medicine, including for the treatment of migraine. In fact the The American Headache Society includes acupuncture on its list of recommended treatments. The reason for this is that acupuncture proponents have been able to change the rules of clinical research so that essentially negative or worthless studies of acupuncture are presented as positive.

I reviewed the evidence for acupuncture and migraine previously, demonstrating the multiple problems with the acupuncture literature in general, and specifically acupuncture in migraines. Most studies suffer from at least one fatal flaw: they are not properly blinded, they do not include a control, they mix acupuncture with non-acupuncture variables (mostly including electrical stimulation in the treatment group), comparison groups are not adequately treated, they make multiple comparisons to maximize chance outcomes, or they are simply too small making them susceptible to all the usual problems of bias in research.

What we don’t see is a consistent and clinically-relevant effect in properly-controlled double-blind trials where the variables of acupuncture are isolated.

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Posted in: Acupuncture, Chiropractic, Neuroscience/Mental Health

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Treating Migraines

I am a headache specialist and so I receive many questions, through SBM, NeuroLogica or listeners of the Skeptic’s Guide to the Universe, about how to best treat headaches, or about a specific, often unusual, treatment. Migraines and severe headaches are very common. According to the latest statistics:

14.2% of US adults 18 or older reported having migraine or severe headache in the previous 3 months in the 2012 NHIS. The overall age-adjusted 3-month prevalence of migraine in females was 19.1% and in males 9.0%, but varied substantially depending on age. The prevalence of migraine was highest in females 18-44, where the 3-month prevalence of migraine or severe headache was 23.5%.

That means about 28 million Americans suffer from migraines. Percentages do vary from continent to continent, but not dramatically. Migraine, therefore, is a huge burden. Headaches can be debilitating when severe, and so also are a major source of lost productivity.

This will be a two-part series reviewing some of the options for treating migraines, focusing on science-based treatments in part I, and non-science-based treatments in part II. None of this is intended to give specific medical advice for any individual. If you have severe headaches you should consult your physician. I will simply be reviewing the evidence for various options, focusing on migraine specifically.

Caffeine, a common trigger for migraines and headaches

Caffeine, a common trigger for migraines and headaches

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Posted in: Neuroscience/Mental Health

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Unfalsifiable Beliefs

sisyphus

As we search for a logo for SBM or the SfSBM, Mark Crislip has been a strong advocate of using an image of Sisyphus, endlessly pushing a boulder up a hill only to have it roll back down again. It’s a bit too self-defeating to be enthusiastic about that suggestion, but it does reflect a common feeling among all of us here at SBM – promoting science can be a frustrating endeavor.

Our frustration reflects a broader phenomenon, that it is difficult to persuade people with facts and logic alone. People tend to prefer narrative, ideology, and emotion to facts. The high degree of scientific illiteracy in the culture presents another barrier.

In recent years psychologists have demonstrated experimentally what we have come to understand through personal experience, that people engage in a host of cognitive defense mechanisms to protect their beliefs from the facts. We jealously guard our world view and are endlessly creative in shielding it from refutation.

A recent series of experiments published by Friesen, Campbell, and Kay in the Journal of Personality and Social Psychology demonstrates that one strategy commonly used to protect our beliefs is to render them unfalsifiable, or at least incorporate unfalsifiable elements. (more…)

Posted in: Critical Thinking

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