Archive for the 'Science and Medicine' Category

Sep 14 2018

New Apple Watch and Health Screening

Apple recently announced two new health features of their Apple Watch – fall detection and heart monitoring. These are being sold as useful health measures, but there are concerns that this new technology may be more gimmicky than useful, and might actually be counterproductive.

The first feature detects possibly dangerous falls. If the motion detector senses that the wearer has fallen to the ground, and then they don’t move for one minute, the watch will automatically call 911. This superficially sounds reasonable, but the concern is that the tech company has not adequately tested this feature in coordination with medical professionals.

Specifically – what is the sensitivity and specificity of this algorithm? How often will it detect an event that reasonably requires a call to 911, and how many false positives will it generate? How much will this overwhelm emergency services?

What is naive about this feature is the lack of appreciation for the fact that medical interventions need to be evaluated. Why, for example, one minute? That is a round number, but is that really the threshold where the true-positive to false-positive ratio is optimal, while avoiding dangerous delays if someone is really injured?

Also, what will be the net effect of this? Will the drain on resources actually cause more harm than benefit to the users? How will 911 call centers handle these calls? Will they be able to interpret them?

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Sep 07 2018

Probiotics – It’s Complicated

A new detailed study of the effects of probiotics on the gastrointestinal microbiome shows how complex this subject is. Unfortunately, the reporting is significantly oversimplifying the results. The BBC reports:

A group of scientists in Israel claim foods that are packed with good bacteria – called probiotics – are almost useless.

That’s not actually what they said, at least according to my read.

Probiotics are pills or foods that contain live friendly bacteria, which are meant to support the beneficial bacteria that live in our guts. This basic idea is not pseudoscience. It is quite reasonable – however, the science of probiotics is very immature. We are still in a phase where we are discovering more and more complexity, and struggling to find any clear therapeutic gains. Meanwhile, the marketplace is making claims that go way beyond the science, and is based on very simplistic notions of how the microbiome works.

In the last decade or so we have demonstrated that the microbiome is an ecosystem at homeostasis. People have about 100 bacterial species in their gut microbiome, which not only colonize their mucous membranes, they keep out other bacterial species. This is an important part of our immune defense – the microbiome prevents infection by harmful bacteria. Further, you can’t just throw one or a few species into an ecosystem and expect to change it.

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Sep 04 2018

French University Dumps Homeopathy

France is the world’s biggest consumer of homeopathic potions. According to a study by Edzard Ernst:

The results show that a total of 6,705,420 patients received at least one reimbursement for a homeopathic preparation during the 12-month period. This number equates to 10.2% of the French population, with a predominance in females (68%) and a peak frequency observed in children aged 0-4 years (18%).

This is unfortunate, because homeopathy is pure pseudoscience, costing French taxpayers €279 million in one year. But there is some good news – homeopathy has been in retreat around the world, at least in terms of official recognition and reimbursement. Homeopathy hospitals are closing in the UK, the FDA has decided to finally start regulating at least the worst homeopathic offenders, and now a French university, Lille, has decided to suspend its homeopathy degree for the 2018-19 academic year.

Further (and here is the big lesson here, in my opinion) this is mostly in response to scientists taking the time to review homeopathy and declare that it is not based in science and does not work.

So what happened in France, where homeopathy is very popular? Well, in March 2018, 124 French doctors signed a statement taking a strong stand not only against homeopathy, but all kinds of pseudoscience in medicine. The entire statement is worth a read, but here are some highlights:

The obligation of honesty is enshrined in the Codes of ethics of the medical professions and the Code of public health (article 39 of the Code of ethics and article R.4127-39 of the Code of public health). The codes forbid charlatanism and deception, impose to prescribe and distribute only proven treatments. The codes also proscribe the use of secret remedies or not clearly mentioning the substances they contain. The Council of the Order of Physicians is responsible for ensuring that its members do not use their title to promote practices whose science has never proven useful or even dangerous. The Council must ensure that doctors do not become trade representatives of unscrupulous industries.

Homeopathy, like other practices called “alternative medicine”, is in no way scientific. These practices are based on beliefs that promise a miraculous and safe recovery.

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Aug 17 2018

Death by Herbalism

“It’s dressed-up quackery isn’t it?” magistrate Daniel Reiss said.

“That’s one view, your honour,” the prosecutor replied.

That is a good summary of pretty much all alternative medicine. Practitioners have gotten very good at dressing it up, enough to even fool academics who aren’t paying close attention. But in the end, it’s all quackery.

The quote above refers to a recent case of a Sydney Chinese herbalist, Yun Sen Luo, who was arrested and charged with manslaughter in the death of 56 year old client he was treating. He advised the diabetic woman to go off her diabetes medication, ultimately resulting in her death. The charge is gross negligence.

The success of alternative medicine over the last few decades has been in convincing the world that what they offer is a genuine alternative to real medicine. They have rebranded it as complementary, and the integrative, but it’s all the same – using unproven, fanciful, or even disproven treatments instead of real medicine. They justify the substitution by appealing to nature, distracting with hand-waving pseudoscientific jargon, appealing to antiquity, or straight-up lying. In the extreme they weave complex conspiracy theories about the medical establishment to scare people away from real medicine.

This case is just one example, but it’s not atypical. The core problem is that we have a practitioner who is practicing medicine without a license, and without the requisite medical knowledge, training, and experience. The con is that if you simply call what you do “alternative” you can get away with it (until you kill someone – and even then, sometimes).

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Aug 13 2018

Dunning Kruger Effect and Anti-Vaccine Attitudes

One of the persistent themes of this blog is that expertise matters. This is not to say the experts are always right (sometimes they disagree with each-other), and there is also a range of expertise, and different kinds of experts can have different biases and blind spots. But all things considered, someone who has formal expertise on a specific topic is likely to know much more about that topic than someone who has read about it on the internet.

Further, most people underestimate the amount of knowledge that exists on a topic, and therefore the vast gulf of knowledge that exists between them and the experts. In fact, the more someone knows about a topic the more they understand how much is known, and the more humble they tend to be with respect to their own knowledge. The flip side of this – people who know little tend to overestimate their relative knowledge – is an established psychological phenomenon known as the Dunning-Kruger effect.

Operationally Dunning and Kruger found in their study that the lower someone performed on a test of knowledge, the greater the gap between their perceived knowledge and performance and their actual performance. At around the 80th percentile and above, people tend to underestimate their relative knowledge. Below that point they tend to increasingly overestimate it, and everyone thinks they are above 50%.

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Aug 06 2018

More Stem Cell Quackery

We’re doing it wrong. We are definitely making an effort to regulate the practice of medicine and sale of health-care products and services to protect the public from fraud and abuse, as we should. But we are doing it wrong, or at least not well enough.

Just one of the many examples is stem-cell quackery, which I have discussed before. Stem cells are an exciting area of research, and the basic technology is advancing significantly. Clinical applications, however, take time, and with a few exceptions we are simply not there yet. We are currently, therefore, in the sweet spot for abuse.

A recent article in the San Francisco Chronicle, called The Merchants of Hope, highlights the problem. The article should have been called The Merchants of False Hope, but otherwise it did a good job of exposing dubious stem cell clinics that have made their way to the US. A decade ago stem cell clinics were popping up in China, India, and other countries with lax regulation, leading to an industry of stem-cell tourism. But now you can find dubious stem cell clinics right here in the US.

Stem cells, for a quick review, are cells that can turn into other types of cells. There are pluripotent stem cells that can turn into several other kinds of cells, such as the cells in your bone marrow that can make different kinds of blood cells. There are also totipotent stem cells that can turn into any kind of cell. Researchers have gotten good at making totipotent stem cells, even out of mature skin cells. This technology holds the promise of treating a long list of conditions by replacing diseased or damaged cells with new ones.

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Aug 03 2018

Placebo Controlled Trials of Vaccines

There is a strong scientific consensus that vaccines generally are an effective approach to preventing infectious illness. The vaccine schedule is arguably the most effective and cost effective health promotion intervention ever devised. Vaccines are a public health home-run.

How, then, to explain the anti-vaccine movement? The anti-vaccine movement is based mainly on science-denial and conspiracy theories. This means they spread a lot of misinformation – the bits of misinformation become articles of faith, and any evidence to the contrary is denied or dismissed.

I recently received the following question, which is framed as a sincere question, but I have my suspicions that it may not be:

Have just read your article.

I fully agree that herbal medicines/substances should have full clinical trials but can never find anyone able to refer me to
any clinical trials placebo versus substance to be tested on vaccines.
So wondered if you could help me as you are obviously a man of science.
Would be very grateful as there must have been clinical trials sometime.
Even my Dr draws a blank.
Many thanks
Pam

Pam may simply be the victim of anti-vaccine propaganda, and may simply lack all Google skills, but the phrasing strongly suggests an anti-vaxxer goading a skeptic with a “gotcha” question. Since this is a common anti-vaccine trope, let me dispel it once again.

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Jul 20 2018

Cancer Patients Using Alternative Medicine Twice As Likely To Die

This is the second study published in the last year looking at outcomes of cancer patients using alternative medicine, showing a negative effect on survival. The same author, Skylar Johnson, was the lead author on both studies. Last year’s study looked at using alternative treatments instead of standard therapy, and the newly published study looks at patients who used at least one standard therapy.

In the current study, just published in JAMA Oncology, the researchers followed a cohort of 258 cancer patients who used alternative medicine, and 1032 matched patients who did not. They found:

Patients who chose CM did not have a longer delay to initiation of CCT but had higher refusal rates of surgery (7.0% [18 of 258] vs 0.1% [1 of 1031]; P < .001), chemotherapy (34.1% [88 of 258] vs 3.2% [33 of 1032]; P < .001), radiotherapy (53.0% [106 of 200] vs 2.3% [16 of 711]; P < .001), and hormone therapy (33.7% [87 of 258] vs 2.8% [29 of 1032]; P < .001). Use of CM was associated with poorer 5-year overall survival compared with no CM (82.2% [95% CI, 76.0%-87.0%] vs 86.6% [95% CI, 84.0%-88.9%]; P = .001) and was independently associated with greater risk of death (hazard ratio, 2.08; 95% CI, 1.50-2.90) in a multivariate model that did not include treatment delay or refusal.

All that means that cancer patients who used alternative medicine in addition to at least some standard therapy were more likely to refuse chemotherapy, radiation, or surgery. As a result patients using CM (complementary medicine, in the jargon chosen for the study) had a 5-year survival that dropped from 86.6% to 82.2%. This represents twice the risk of dying over this time.

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Jun 18 2018

Gut Microbiome and Anxiety

Humans are a symbiotic creature, like pretty much all other animals. It is estimated that there are as many bacteria in your body as there are human cells. Bacterial cells are much smaller, so this amounts to 1-3% of body weight.

Bacterial cells line all mucous membranes, where they serve critical functions. They are a critical part of our immune system, crowding out other bacteria and organisms that can potentially cause infection. Many of our bacteria live in the gastrointestinal system, our “gut microbiome” , “microbiota”, or “flora”, where they also aid in digestion.

As is often the case, scientists have been discovering that our relationship with our friendly bacteria is more complex than we thought. The microbiome is not a collection of random bacteria, but a stable ecosystem. There is also evidence that there are only a few distinct types of bacterial ecosystems in people. We have an “enterotype” which may affect our health.

There is also growing evidence that our gut microbiota not only have local effects within our GI system, but may have remote effects on the brain and nervous system. This suggests that some bacteria produce neurotransmitters, hormones, or some chemical signal that can get into the blood and then travel to other parts of the body and have an effect.

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Jun 07 2018

Homeopathy Loses NHS Case

The National Health Service (NHS) in England decided in November 2017 to stop funding homeopathic treatments. That was an excellent decision, made for the right reasons – “lack of robust evidence of clinical effectiveness”. While I think that is an understatement, it is true enough, and is sufficient justification for any modern health care system to abandon homeopathy.

Now a High Court Judge has affirmed that decision by the NHS. Why was a judge even involved? Because the British Homeopathic Association (BHA) sued the NHS over that decision.

Legally, this case was fairly straight forward. The judge was  clear to point out that it was not his job to review the scientific evidence regarding homeopathy. The BHA argued in court that there is “plain evidence that homeopathic treatment does work in particular cases”. That is complete nonsense – homeopathy is nothing but magic potions, with no scientific plausibility, and the scientific evidence clearly shows that it does not work for anything.

But the judge did not have to get into that in court, which is appropriate. It should not be for a judge to make scientific decisions like that. His job was to answer the BHA complaint that the NHS was being unfair in their decision. The judge ruled, however, that the NHS process was “fair and balanced” and that “there was no evidence of ‘bias or predetermination'”.

I do worry when such issues come up before courts or regulatory bodies. It is easy to make the claim of bias against those who are simply following the evidence. It would, for example, be easy to make the case that I am “biased” against homeopathy. After all, I have been regularly trashing the pseudoscience for years. But in reality I am just following logic and evidence. Correctly stating that something is pseudoscience is not a bias when it is the logical conclusion of a fair process.

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