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Judging the quality of science sources


Note: this article has been substantially updated, just click the link.


Recently, I wrote articles on skepticism and debunking pseudoscience, both of which require large amounts of evidence. And of course, a true scientific skeptic needs to judge the quality of evidence, because individuals who push science denialism often cherry pick seemingly high quality science to support their beliefs.

A good scientific skeptic needs to decipher the science (or pseudoscience) in popular news articles, for example, to determine its validity. We should be critical, if not skeptical, of what is written in these articles to ascertain what is or is not factually scientific. We even need to determine the quality of science from the best to the weakest, so that we can determine the level of authority of the science before we pass it along to others.

With the social media, like Facebook and Twitter, which provides us with data that may not exceed a few words, then it’s even more imperative that we separate the absurd (bananas kill cancer) from the merely misinterpreted (egg yolks are just as bad as smoking).

Wikipedia is one place which can either be an outstanding resource for science or medicine, or it can just a horrible mess with citations to pseudoscience, junk medicine pushers. For example, Wikipedia’s article on Alzheimer’s disease is probably one of the best medical articles in the “encyclopedia”. It is laid out in a logical manner, with an excellent summary, a discussion of causes, pathophysiology, mechanisms, treatments, and other issues. It may not be at the level of a medical review meant for a medical student or researcher, but it would be a very good start for a scientifically inclined college researcher or someone who had a family who was afflicted with the disease.

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Marijuana and cancer – Sanjay Gupta’s anecdotes are not science

Editor’s note–this article has been updated and included into a multi-part series on marijuana and medicine. Check it out there. 

Unless you were hiking in the Amazon River jungles, with no access to the internet or American TV, you probably have heard that CNN’s chief medical correspondent, Dr. Sanjay Gupta, changed his mind about marijuana (or “weed” as he keeps saying). Of course, this has become big news, because he’s such a “respected doctor” (why is that? Because he’s on TV?), and because a few years ago he was vociferously anti-cannabis.

I have no doubt that Dr. Gupta’s “conversion” to being pro-weed is genuine (and that his previous stance of anti-weed was similarly authentic), but we need to weed out what is real and what’s just smoke about his comments. His first major point about cannabis* was that the United States Drug Enforcement Agency (DEA) considers marijuana to be a Schedule 1 drug, which is defined as “drugs with no currently accepted medical use and a high potential for abuse.”

Dr. Gupta thinks this classification is ridiculous, and on the surface, many people, even those who are not devoted pot smokers, would probably agree. However, this is a political discussion, at least in the USA, and it is hardly a medical/scientific one. The chances of any political party having the fortitude to correct this classification is about as close to 0 as you can get, without actually stating that there is a 0 chance. But if Gupta wants to make a big deal of this, or that he’s so self-centered that he thinks he’ll change the mind of politicians, more power to him. But for me as a skeptic, it is not the most important thing he says.

In his article, he mentions a young girl who “started having seizures soon after birth. By age 3, she was having 300 a week, despite being on seven different medications. Medical marijuana has calmed her brain, limiting her seizures to 2 or 3 per month.” This is simply an anecdote of no quality whatsoever. Did he thoroughly investigate her case to determine if the number of seizures actually went down? Do we know that cannabis has anything to do with the change? Is this nothing more than a Post hoc ergo propter hoc fallacy, that just because she consumed cannabis and the seizures decreased does not mean anything about cannabis’ causative properties with regards to this type of seizure. And then, Dr. Gupta continues with the anecdotes by stating, “I have seen more patients like Charlotte first hand, spent time with them and come to the realization that it is irresponsible not to provide the best care we can as a medical community, care that could involve marijuana.” Why do these TV doctors (like Dr. Oz) think that their anecdotes are better than anyone else’s.

Anecdotes are useless because they aren’t controlled, because they are subject to all levels of bias, and because these stories aren’t peer-reviewed. In other words, anecdotes have no value in science-based medicine. Anecdotes do have value in formulating testable scientific hypotheses, but assuming that anecdote=data, and more anecdotes=more data is simply pseudoscientific. I don’t care what Sanjay Gupta writes or says publicly, but providing these stories as “evidence” that marijuana has a medical benefit is essential like telling me that he observed homeopathy (which is just water) working. It’s laughable.

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Acupuncture for treating Bell’s palsy–myth vs. science

4acupunctureOf all of the alternative medicine therapies, acupuncture is the one that seems to get the most research money, and gets the most claims of effectiveness. Emphasize “claim”, because as of yet, there are no studies that show anything beyond a placebo effect, and some have shown results worse than placebo. Most of the studies are poorly designed, with poor control groups, with poor results.

Here are just some of the Cochrane reviews of acupuncture research that conclude that acupuncture lacks any clinical efficacy:

That’s just a few of many negative studies. 

So what is acupuncture? Its theoretical basis is that health and sickness are caused by the good or bad flow of Qi through the body, in particular along the twelve major meridians of the body (though some authorities list fourteen or even more) which run from head to toe along the body, and which are associated with the bladder, gallbladder, heart, large intestine, small intestine, kidneys, liver, lungs, spleen, stomach, pericardium, and other things. It is a form of woo medical procedure based on sticking needles into the dermis at precise points to affect the Qi. Except there is no evidence at all that this Qi exists. It’s pseudoscience.Read More »Acupuncture for treating Bell’s palsy–myth vs. science

Antioxidant supplements for cancer–myth vs. science

I’ve never been a fan of vitamin supplements. Aside from a very few supplements intended for a few specific clinical conditions, like vitamin C and scurvy, they have little use in preventing or treating diseases. In fact, because mammalian physiology has evolved a homeostasis for these chemicals, any excess amount that can’t be stored in the fat or other tissue is cleared by the kidneys and becomes part of your urine. I’m willing to venture that the urine of many Americans is quite expensive, with all of the cleared vitamins and other micronutrients. A balanced diet over several weeks is sufficient to provide the body with all of the nutrients and vitamins to be healthy and strong. You are not even required to have all vitamins and nutrients every day, as storage of a few nutrients will be released as necessary, and clinical manifestations of nutrient deficiency may take weeks or months.  

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Tamiflu-does it work

According to the CDC, this year’s flu season is pretty serious in the USA. Current data, shows that about 4.6% of patient visits to health care providers are for influenza like illnesses (ILI). Thirty states and New York City are now reporting high ILI activity; an increase from 24 states last week. Additionally, 10 states are reporting moderate levels of ILI activity. Forty-eight states reported widespread geographic influenza activity for the week of January 6-12, 2013. This increased from 47 states in the previous week. 



Although there has been a slight drop-off in ILI visits over the past couple of weeks since the peak in early January, the CDC continues to identify this season as a “moderately severe” one, and supplies in some areas have tight supplies of the flu vaccine. Read More »Tamiflu-does it work

Vaccines do save lives, and science can demonstrate it

If you spend any time reading the antivaccination rants, you will hear about all kinds of conspiracy theories, pseudoscience, and scaremongering. Given that there is little scientific evidence that supports their beliefs, they have little choice but invent strawman arguments to make their point. One of the more amusing strategies of antivaccine cult is to claim that diseases were going away before vaccinations. These people believe, without any evidence whatsoever, that diseases like polio, measles, and chickenpox were disappearing because of better sanitation. Or better nutrition. Or something other than what really ended these diseases–vaccines. It’s a historical revisionism of a legendary level.

Admittedly, part of this belief is that people lack the cultural memory of some of these diseases. Few parents born after 1970 would remember classmates who had been stricken with polio. Few would have remember measles, mumps, or other epidemics sweeping through a school. They just don’t remember it, because vaccines introduced in the 50’s and 60’s reduced, and in the case of smallpox, eliminated the disease. Of course, there is evidence that support the theory that vaccines end diseases. But we don’t have to go back 40 or 50 years to show this happens, but we can talk about a disease that has been drastically reduced in the last few years, just because of a new vaccine.

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“Homeopaths without Borders” going to Haiti to provide water

Yes, there is a group called Homeopaths without Borders. Apparently, the group that does lifesaving work across the world, Doctors without Borders, are too busy, utilizing real evidence-based medicine with real medications, risking their own lives, and doing great works, to be worried about homeopathy, a pseudoscientific concept, even if this group steals their imprimatur without shame.

Homeopaths without Borders are sending their water magicians to Haiti, a country that has had to suffer so much during the past few years. During their time their, “the team will be in Port-au-Prince to complete the final session of the Fundamentals Program—a foundational curriculum in homeopathic therapeutics incorporating theoretical and clinical training.” Clinical training on the poor residents of Haiti? Have they not suffered enough?Read More »“Homeopaths without Borders” going to Haiti to provide water

Echinacea and the common cold–Myth vs. Science

It’s getting close to winter once again, so people always recommend their various lotions and potions to either prevent the common cold or, at least, to reduce the course of the disease. Alternative medicine’s favorite disease to treat is the common cold, mainly because it’s an easy disease to handle without too many serious problems. Also, from the patient’s perspective, the length and seriousness of the cold is usually very subjective, since the patient has a difficult time making an accurate determination when the cold started or ended, and making a quantitative assessment of the seriousness of the disease. Moreover,  confirmation bias is usually the reason one hears that something worked for the cold–the person who reports some product works forgets all the times it doesn’t. Or completely misjudges the actual effects of any treatment.

The list of products that you might run across in your local pharmacy that claim to have an effect on the common cold are many. Zinc, oscillococcinum, garlic, and vitamin C. I wrote about these products last winter, and they mostly don’t work. The strangest cold remedy you might find is oscillococcinum, which is a homeopathic preparation derived from duck liver and heart, diluted to 200C, or 200 1:100 dilutions.  In other words, in a liter of water there are precisely no molecules of duck guts. And there isn’t any logical explanation of a possible mechanism that would allow one to conclude that duck offal has an effect on cold viruses. Though Oscillococcinum is supposed to be used for flus, many use it for colds, but it doesn’t matter, why would a diluted potion of duck guts cure any virus? Well, Cochrane Reviews concluded that ”current evidence does not support a preventative effect of Oscillococcinum-like homeopathic medicines in influenza and influenza-like syndromes.Read More »Echinacea and the common cold–Myth vs. Science

What is causing the fatal meningitis outbreak?

Over the past week or so, there have been numerous reports about a fungal meningitis outbreak that was traced to medicines associated with three lots of preservative-free methylprednisolone acetate produced by the New England Compounding Center.  The drug is an injectable steroid that is used for pain relief. The potentially contaminated injections were given starting May 21, 2012. Symptoms of the fungal meningitis include: fever, new or worsening headache, neck stiffness, sensitivity to light, new weakness or numbness, increasing pain, redness or swelling of the injection site. So far, 7 people in the US have died.

Because the drug is delivered via an epidural injection directly into the epidural space, any contamination can lead to a meningitis infection. In this case the steroid produced by the New England Compounding Center was contaminated with a fungus which caused the fungal meningitis. It’s important to note that unlike other types of meningitis, such as bacterial meningitis, it is not contagious. Fungal meningitis also does not have a vaccine, because it is quite rare. (Viral meningitis is less severe, and usually resolves itself without treatment.)

Data Table for Persons with Meningitis Linked to Epidural Steroid Injections, as of October 7, 2012

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Ginkgo biloba and neurological disorders–Myth vs. Science

I’m trying out a new series, looking at some popular myths (mostly in medicine, but maybe we’ll wander outside of it when something interesting shows up) and determining if there’s any support or not in science. I’m going to link mostly to science articles and high-quality blogs, just so you have all the back-up evidence that you need. One way or another.


Ginkgo biloba is actually an interesting plant because it has been relatively unchanged for nearly 270 million years. It is considered a living fossil, an informal term used for species like G. biloba that appear to be the same as a species otherwise only known from fossils and which has no close living relatives. The genus Ginkgo was fairly widely distributed until about 100 million years ago. It slowly disappeared from the fossil record until it was found only in one small part of China about 5 million years ago, where it is found today.  

The tree is native to China and is known to have been widely cultivated early in human history. It is used as a food source by various Asian cultures, with the Chinese eating the meaty gametophytes and the Japanese the whole seed. Unfortunately, the seed contains a chemical, 4′-O-methylpyridoxine, that can be poisonous if consumed in enough quantity. Read More »Ginkgo biloba and neurological disorders–Myth vs. Science