Archive for the ‘ Science ’ Category

The Scientific Method On TV


Last week Michael Edmonds asked “Which TV Show Best Demonstrates the Scientific Method?
Various shows where suggested such as CSI and NCIS. Bones made an appearance in the comments as one show that exhibits a fair amount of pseudoscience along with it’s “real” science. House was praised for it’s attention to hypothesis generation and testing. I generally agree with that but found the fact that House always came up with the correct answer alone and via an epiphany type insight a bit unsatisfying.

In any case most shows do poorly at portraying science, this comes inevitably out of the fact that the show is there to tell a story. The science may or may not help with that but in the end it is merely set dressing for the real aim. I’m fine with that – I watch a lot of tv and aside for the odd grumble along the lines of “It would take longer than that!” or “You wouldn’t do it that way!” I’m happy enough to suspend my criticism and enjoy the ride.

But the question remains – which show does it best? Over the weekend an answer came to me that might be cheating a bit, but I think the best I’ve seen lately is one called “Guess with Jess“*.
Guess with Jess

If it sounds like a kids show, you’re right – it is.

The basic set up is like this: A cat decides on a question for the day and then sets about trying to answer it. Pretty simple.

I think it does pretty well showing the methods of science:
A question is generated via an observation of the world, a “literature” search is conducted to find what is already known on the topic (via asking the other animals), a hypothesis is generated that fits the question and what is known, the hypothesis is tested and the results observed to see if it answers the question. Often the first attempt is incorrect, so the question is refined, another “literature” search is conducted, another hypothesis generated and another round of testing conducted.

At the end an answer is arrived at which satisfies our feline protagonist and everyone is happy at having learned something new. Possibly Jess goes off to write a grant proposal – I’m not sure.

So that’s my answer. Adult fiction is too focused on telling a compelling story with relate-able characters in a limited time frame to make more than a passing effort at getting the science right. But that’s ok, we can rely on a young cat named Jess to pick up the slack.

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* If a black and white cat named Jess sounds familiar, you might remember that this describes the cat of Postman Pat. According to wikipedia they are one in the same, I’m not sure if Jess has been put out to pasture or if this depicts Jess’s life before settling down with Pat.

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Science Literacy Test Initial Follow-up


Yesterday’s post about the Science Literacy test has gotten some good responses.

Thought I’d put up a couple of initial thoughts/feed-back on the testing:

First off it’s becoming clear that some of the questions are ambiguously worded. This is especially obvious in the results for questions 12 and 14.

Question 12, looking at categorizing sources, is worded in such a way that it is not clear whether the question refers to the story extract itself or the sources used in the story extract. This means that respondents incorrectly label the source as “Primary” (correct for the sources used for the story extract) and “Tertiary” (correct for the story extract itself and therefore the correct answer for the question).

The other one that people are obviously getting wrong because of the wording (including myself) is question 14. This question asks what element of a study design is not a strength of the study.

This implies that you are to critique the design as it is actually presented, not how it could have been. Thus people are choosing the option that is “least wrong”. A bit of a change in this wording to make it clear what design could have been used but wasn’t or that could have made the study better or even restricting the answer options to just the study elements present in the background information would probably bring the score for this question up.

Interestingly there are a few questions nobody has gotten wrong, indicating they may be a little too easy (but perhaps the sample size is still too small yet, 45 responders so far).

The first question “Which of the following is a valid scientific argument?” has a 100% responder correctness score. As does Question 16 on the proportions of house building materials and question 20 on the rat population. Question 27 “Which of the following actions is a valid scientific course of action?” also has a 100% score.

So, great stuff so far, as I mentioned there’s been about 45 people taking part so far and things already are shaping up nicely. So spread the word and lets see how many people we can get. If possible it would be nice to get constructive criticism on the question wording like I have done above that can be feed back to the original test designers.

Thanks for the interest so far and keep it up!

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Test your Science Literacy Skills


Last week an interesting paper was published outlining the development of a test designed to evaluate science literacy. The basic idea of the test is to examine a number of different skills that are involved in evaluating scientific claims and facts.

I liked this idea so much I decided to put together an online version of the quiz that people could take and get instant feedback for. This could also be adapted for use in an educational environment as intended in the original paper.

To that end I need beta testers, people who would like to take the test and give me feed-back on how to improve it. A couple of things I need to mention at this point:
First, the test will ask for your email address in order to send a summary of how well you did on the test. Your email address will not be used for any other purpose and indeed I’ve set up the back-end so that the address will be deleted as soon as your email is sent – your private information will remain that way.
With this in mind – If you have feed-back about your performance, there is no way for me to tell which entry is yours unless you give me the time you submitted the form.

Secondly, I have used some custom html code in creating the form which doesn’t integrate seamlessly with the google drive document that runs most of the functionality. This means if you miss a required question (all of them are required FYI) than you will be re-directed to the original form of the test, this will look a bit different and will not contain the pictures (but will have urls you can use to get to them).
You can either continue with this version of the form or hit your browser’s Back button and fill out the questions you missed there.

Finally, If you have and comments or suggestions leave them here and I’ll see what I can do. Also I am actually fairly mediocre at html coding and such like so if there is anyone who wants to volunteer their services to upgrade the quiz I’m happy to share the load :) .

Ok, here’s the link to get you started, have fun.

[Edit: Here's a link to some initial analysis of the results]

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Anti-Vaccine Charity, No More


Last year I wrote a series of posts[1] around the Charitable organisation Immunisation Awareness Society and a complaint I had made to the Charities Commission. The Thrust of these posts and the complaint was that the Society does not fulfill the requirements of a charity and should be removed from the register. The effect of this is that they would also be stripped of their tax exempt status.

This indeed was my main goal. There are innumerable groups out there that I don’t agree with but you get that in a wide and varied world. In the case of the IAS though the speech they engage is is effectively publicly subsidised via the tax exemption, this should mean that they are constrained in what they can say. At the very least it should mean that they must present the facts undistorted by ideology.

Yesterday I found out that the Charities Commission agrees with me. In a decision handed down late last month they determined that the IAS does not qualify for charitable status and removed them from the charities register.

So, I guess you could say – I won.

It the words of one of my colleagues it also shows that one person can make a difference. Clichéd but true.

Reading through the Charities Commission decision it seems they focused on two things:

1. The biased nature of the information provided by the IAS and;

2. The political nature of their campaigning for a change in public policy.

This makes sense given the requirements that the Commission need to fulfil to determine whether an organisation meets the requirements to be a charity. Even so I’m a bit disappointed that there was no focus on the factual inaccuracy of and misrepresentation in the materials published by the IAS.

The decision does seem to skirt this line though when stating that  “Overwhelmingly, the information on the website argues that vaccination is ineffective and dangerous” the inference being that is view is incorrect as well as being biased. Even so, none of the language of the report actually states this outright (that I can see).

There was also an additional point touched on that merely providing information does not in and of itself “advance education”. In other words to be an educational charity you actually have to actively educate people, not simply act as a repository of information – otherwise every private citizen with a decent library or informational website could become a charity.

Finally, in my personal 15 minutes of fame, the Commissions decision has been reported in the Dominion Post – complete with a quote from me. Not my most eloquent moment but it’s close enough to the point I wanted to make that I’m fairly happy.

[Edit: Thanks goes to commenter Hemlock for sharing the IAS response to this news]

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1.  And here they are in all their tedious glory:
http://scepticon.wordpress.com/2011/10/11/anti-vaccine-charities-is-there-any-quality-control-on-charities/

http://scepticon.wordpress.com/2011/10/11/ias-complaint-part-1-thimerosal-in-your-vaccine-no/

http://scepticon.wordpress.com/2011/10/12/ias-complaint-part-2-gardasil-horrors-horrific-reasoning/

http://scepticon.wordpress.com/2011/10/13/ias-complaint-part-3-vaccine-ingredients-not-so-bad-really/

http://scepticon.wordpress.com/2011/10/14/ias-complaint-part-4-anti-vaccine-impact-in-new-zealand/

http://scepticon.wordpress.com/2011/10/17/defending-the-term-anti-vaccine/

http://scepticon.wordpress.com/2011/10/18/the-legitimate-risks-of-vaccines/

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Energy Mirages and the False Hope of “Water Powered Cars”


This morning while perusing my news feeds I saw this article lamenting the state of scientific ignorance and bald political grandstanding in Pakistan. The specific item that prompted this lambasting of an entire country is the claim by one individual to be able the fuel cars using water – and the near unanimous support of this character within the political and scientific realms – despite the physical impossibility of this feat.

I think the author of this article is quite correct in his condemnation of this person and those who support him who tout this technology as a solution to the country’s energy woes. That said I think he does his audience a disservice in not breaking down the claims more fully to explain why this “invention” is not all that it seems and why it will not act as a panacea for the dependence on fossil fuels and the deficit of energy that Pakistan endures.*

It is explained that you cannot run a car on water due to the fact that that it would require a reversal of the second law of thermodynamics. A law that is deemed so fundamental to the operation of the universe that it prompted this quote from a distinguished scientist:

“The law that entropy always increases, holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell’s equations — then so much the worse for Maxwell’s equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation. ”

Sir Arthur Stanley Eddington, The Nature of the Physical World (1927)

But this is not the end of the story. For while the “inventor” and his supporters use the word “fuel” to refer to the water, it is a misnomer as we normally understand the word. A fuel is something that supplies energy, it stores energy that is created by one of any number of processes and enables it to be used to do work seconds, hours or millennia after the energy was first produced.

This is what fossil fuels are – the condensed energy of biological processes that occurred millions of years ago. We tap this energy and use it to run our cars, and depending on where you live, the entire rest of our lives.

So what’s this to do with water?

Well, simply put water is the end product of energy use. It is not a storage medium it is a waste product. It would be like saying you’ll run your furnace on ash. You would be laughed out of the human race. But say you’ll use the magical liquid of life – water – and for some reason people think there’s something to this idea.

Now, what is the proclaimed inventor claiming? When you get right down to it he knows the water isn’t a fuel. He is in effect using the water as a convenient hydrogen source. It is the hydrogen that runs the car, and presumably the “water-kit” enables the car to process this hydrogen as it would petrol. The kit also contains an electrolysis component that splits the water into hydrogen and oxygen. I am unaware as to whether the oxygen released is retained to react with the hydrogen or whether atmospheric oxygen is used for this.

In any case the energy for running the car comes not from the water, but the batteries used to extract the hydrogen. The hydrogen then becomes the interim energy storage medium and the “fuel” for the car.

What we have then is the energy generation being pushed back a step, instead of being done at the car via petrol, it will be handled by the country’s power plants.

I can well imagine that there are benefits to converting cars to this set-up. It effectively turns your automobile into one of this new fangled electric cars without the downside of looking like a self-righteous dick*. There are benefits to using electric cars even if the ultimate power generation comes from fossil fuel consuming power plants (which by my calculation more than half of Pakistan’s electricity comes from) such as local air quality improvements. The ability to deal with emissions at centralised locations and the possibility of sequestering that pesky CO2 at the source.

I suspect however that in the rush to embrace the technology at issue here these peripheral concerns are not really being considered. And for a country that already has too little electricity for the population it has (40% of the country has no access to electricity, and demand is ever increasing for those that do) this does not sound like such a great idea and won’t result in everyone having unlimited fuel for their cars. It can only add to the pressure on the already over-taxed electrical grid.

In addition it is being implied (if not outright stated) that water could be used to run generators. This is where you could justifiably call fraud. While there are conceivable reasons why you might convert a car to “run” on water those reason evaporate when you try to argue that the same can be done for a generator. I’m sure you can see why. You end up just inserting an extra step in the energy generation process, well more like a loop. You have to provide energy to the water to extract the hydrogen and then burn the hydrogen back to water to get the energy. Thanks to that second law thingy you will never get more energy out of that reaction than you out in.

Not only do you insert a completely useless extra step, in doing so you guarantee that the whole process is less efficient. You literally get less combustion for your buck.

I hope that no government official is seriously considering funding a project to replace generators with water powered devices, though I gather millions may be spent investigating the possibility of employing this technology in Pakistan. I don’t know where that money (assuming people don’t wake up by then) is intended to go.

This is the concern whenever fringe theories and technologies are held up as the solution to our problems, that money will be wasted on these rather than put toward more worthy projects.

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* A more thorough treatment is here, by former chairman of the Pakistani – Higher Education Commission  Dr Attaur Rehman.

** Just kidding. For what it’s worth I think electric cars are really cool and if I could spare the dosh would love to have one. But I gather there is something of a stigma and well it’s a joke – lets not analyse it too much eh?

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Monday Afternoon Movies: From Daleks to Vectron


I was collecting up videos to drip feed when I got around to it, but figured I may as well post them all at once to liven up a Monday afternoon.

Enjoy.

The Great and Powerful Tyson…

Dan Dennett on “Deepities”…

“Vectron” from the amazingly funny Mitchell and Webb….

Levitation, I have to admit while watching this I was grinning like and idiot..it’s awesome….

Richard Wiseman amazes and astounds….

Daleks: Hitchhiker’s Guide style…

Amber Teething Beads: A Follow-Up


Over the week or so I expect the page views for my amber teething necklace post to top 20,000 over the two blogs. Interest in the article has just kept increasing over the last year or so of it being up, as opposed to the majority of my posts which slip into internet obscurity within days. In anticipation of the occasion I thought I’d cover some of the comments that this post has gathered over the last few months.

Many of the comments are along the lines of “It worked for me” and “Try it yourself”.

To the first, I don’t really have much to say. I can’t peer inside the inner workings of your child and determine what is going on. But at the same time a bunch of individuals making claims of efficacy without adequate control for bias, natural history and various other contingencies is not a compelling argument to me. Plenty of others swear by practices that have no hope of working*, why should this one get more credibility based on personal experience?

As to the second, three words for you: Anecdote and Confirmation bias. I know enough to realise that I am not immune to the wiles of confirmation bias, which would make my trial just another anecdote – something I don’t accept from others so what would make my own experience any more valid? I also realise that for most people this sort of reasoning is at best foreign and at worst incomprehensible. The general thinking appears to go something like “If I try something and it seems to work, then it works – QED”.

No.

Related to this point are appeals to the “Placebo Effect”, the idea being that simply trying something helps, somehow. This may be true. But I’ll expand on the faulty reasoning behind this assertion.

The placebo effect as this seems now to be the “go-to” explanation for all things unexplained so it might be a good idea to dwell on this concept on it’s own for a bit. First off with regard to talking about the placebo effect, it depends on what you mean. The placebo effect started off being simply the improvement seen in the control group for clinical studies. It was the group that was given everything except the active treatment. Therefore by definition the placebo response is what happens when people aren’t treated. It was the catch all for everything that could affect the outcome that wasn’t due to the treatment itself: poor method design, confirmation bias, reporting bias, observer effect on the patients, regression to the mean, natural history of the disease, etc, etc.

Recently there has been some work done to see if there is a real change in people that is due to thinking they are getting an active treatment, the so called “Placebo response/effect”, this has been mixed. It is true that people will report less pain and their brain will show less activation in pain related areas. But people are susceptible to what they are told, it turns out if you tell people a cheap wine is expensive they will enjoy it more. Is there a placebo wine effect? possibly, but the wine didn’t change and neither did any underlying physiology in relation to placebo medical treatments.

In fact recent studies in asthma showed that while people reported feeling better while taking placebo their ability to perform on objective measures remained the same, while those on active medications improved. If you feel better while still having a life threatening condition are you better? I don’t think so.

So in appealing to the placebo effect you have to concede that 1. the beads don’t have any active ingredient, and 2. don’t make any difference to the underlying condition.
i.e. They do nothing.
Now notice in my original piece this is not what I say, I merely point out there is no good reason to think they are doing anything, not that they definitely aren’t. A subtle distinction I admit.

In essence the argument becomes: “If you think it works then it does”, well I would counter with why don’t you use something that we know does work and then you can capitalise on both effects: You will think it works and it will actually work too. Double goodness.

One poster asserted that amber necklaces were registered with the Therapeutic Goods Administration in Australia as a Medical Device. Arguing that this must mean they have therapeutic properties.

This one was my favourite as it was almost laughably easy to dismantle. After only a few minutes I found that this was completely untrue (you can search the TGA resister here). Not only that but there were suppliers admitting** that they couldn’t claim therapeutic benefits because they were not on the register:

“Amber Teething Necklace Information – TGA Australia

Due to regulations of the Therapeutic Goods ACT, policed by the Therapeutic Goods Administration (TGA), whose register does not recognise the claimed healing and theraputic[sic] properties of Amber we are unable to offer any detailed information on Amber Teething necklaces or Amber in general in a theraputic[sic] advisory capacity.

Therapeutic goods are defined in the Act to include goods that are represented in any way to be for therapeutic use. Therapeutic use is defined to include use in or in connection with influencing, inhibiting, or modifying a physiological process in persons.

In all amber related cases that we have seen, the TGA Panel note “that the advertisement appeared likely to breach section 42DL(1)(g) of the Act, which prohibits the publication of advertisements for therapeutic goods that are not included in the Register“” [Emphasis added]

A complaint was made against a supplier for making claims for the product and this was upheld in part because the necklaces are not on the register.

“The Panel noted, without making any formal finding, that the advertisement appeared likely to breach section 42DL(1)(g) of the Act, which  prohibits the publication of advertisements for therapeutic goods that are not included in the Register.

The website involved changed their wording to get around the regulations, spot the difference:

OLD: “natural pain relief provided by Amber works by placing the necklace on your body, this allows your skin to warm the amber beads, releasing healing oils which are then absorbed into the blood stream.

NEW: “Amber is believed to soothe naturally, when Amber is worn next to the skin it is warm and it is reputed to release natural oils that can care for the skin.”

What a difference a few words make.

At the time the comment was made alleging the necklaces were on the register I suspected that intended therapeutic benefits would be enough to fulfil the therapeutic benefits category.

This is supported both in the declaration of the supplier above and from the wording from the complaint, just prior to the excerpt above it states:

Therapeutic goods are defined in the Act to include goods that are represented in any way to be for therapeutic use. Therapeutic use is defined to include use in or in connection with influencing, inhibiting, or modifying a physiological process in persons.

In representing the advertised products to have an “active ingredient”, to release “healing oils which are then absorbed into the blood stream”, and to relieve teething in infants, the advertisement clearly constituted an advertisement for therapeutic goods.” [Emphasis added]

Lets say though that the product had been registered with the TGA or will sometime in the near future, I would note that unless the administration was in possession of studies that are not published elsewhere there is no way that they could be sure that an actual benefit is occurring. Bringing us right back where we are now.

As an extra note on the activities of the Australian government on this topic I found it amusing to see that the Australian Competition and Consumer Commission issued a safety warning about Amber teething beads end of September last year (see here and here and here).

I say amusing because, while it’s not impossible, I do find it unlikely that one branch of the government is condoning their use while another warns against them. Luckily this is not actually the case.

Finally, this post is not intended to address every conceivable objection to my arguments, merely a survey of what has been proffered so far. I am not really convinced by anything I have yet seen but I remain open to changing my mind so long as the evidence is of good quality. It doesn’t have to be much, a good start would be something that suggests succinic acid has the analgesic properties attributed to it. Then we could address whether succinic acid is released from the beads at ambient/skin temperature. Finally we would need to tackle whether the succinic acid is absorbed topically in any significant dose (decent dose response curves could be obtained at stage one of this theoretical research programme).

All three of these items would need to be looked at in order to state that amber beads have good plausibility for what they are marketed for.

[Update 29/4/13: Apparently there is a chain email circulating blaming amber beads for a case of SIDS. This seemed implausible to me and a very brief check seems to back up my gut feeling. There is no reason to think that amber beads contribute to SIDS at all. For a more thorough break-down go here: http://www.hoax-slayer.com/amber-teething-necklace-sids.shtml . I am not one who feels we need to latch onto any reason to vilify our intellectual opponents and spreading misinformation (especially easily debunked misinformation) is a big no-no in my book.]

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*Not that I think this product has “no hope” of working, it could as far as I know. We just can’t make that determination on the basis of anecdote and there are no trials that I’m aware of.

** Argh, this site seems to have removed any trace of of this page. Should have archived it. It has essentially been replaced with this (archive):

In keeping with Australian Fair Trading guidelines no therapeutic claims are made and no medical advice is offered. The material provided on allaboutamber.com.au is for information and educational purposes only and is not a substitute for medical treatment or diagnosis. We assume no responsibility for treatment or cure of any illness or disease. If you have a health problem we recommend seeking medical advice from your qualified natural/health professional. This information is strictly a source of general information and is not intended for use as a tool for self-diagnosis. All About Amber provides this information for you to make your own decisions, if you want to use them on your own family, we believe they work for us and please read the reviews to gather many other peoples opinions.

Which seems to me to be saying “We can’t claim the beads have any healing powers directly, but they really do.”

They haven’t yet learned this lesson for Hazelwood jewellery (archive)though:

How does hazelwood jewellery work?

Hazelwood products are believed to help to create an alkaline environment in your body, which may help, precent[sic] and appease many of the symptoms caused by being to acidic. Hazelwood, being an alkaline wood, has the natural property of absorbing and neutralizing the body’s acidity through contact with the skin. By doing so, the necklaces can also help with digestion, constipation, eczema, migraines, acid reflux, heart burn, nausea, arthritis, skin problems, etc. If you suffer from one of these issues, it is highly probable that you are suffering from an acidity imbalance, and hazelwood may be able to help you alleviate these symptoms in a natural way.  Most people who suffer from an unbalanced pH are unbalanced towards the acidic. This condition forces the body to borrow minerals—including calcium, sodium, potassium and magnesium—from vital organs and bones to buffer (neutralize) the acid and safely remove it from the body.

Hhhhm, perhaps another post is in order. And a complaint.

As a brief aside, as it seems there are quite a few parents out there hungry for this information if you know of a good parenting or early childhood publication that would be willing to print the original article (probably in an altered form) then let me know.

And I’ll stop there before the footnotes become longer than the post.

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Why Do People Use Alternative Medicine?


ResearchBlogging.orgI often read that the reason people are turning to complementary/alternative/integrative(take your pick) medicine is because they are dissatisfied with the care received from mainstream/conventional/”western”* medicine. This may be true for a small segment of the population, those with a chronic illness or with terminal cancer spring to mind. But is this generally true of altmed users? Those who pick up a bottle of homeopathic remedy from the pharmacy or occasionally visit a naturopath?

I don’t think it’s quite as simple as that. A study “Why Patients Use Alternative Medicine” published in 1998 in the JAMA looked at this question using a survey sent to randomly selected participants. 1500 participants were sent the survey and 1035 completed it. Not too bad for a survey response rate.

The survey was geared to look at the use of altmed based on three paradigms:

“1. Dissatisfaction: Patients are dissatisfied with conventional treatment because it has been ineffective,5-6 has produced adverse effects, or is seen as impersonal, too technologically oriented, and/or too costly.

2. Need for personal control: Patients seek alternative therapies because they see them as less authoritarian16 and more empowering and as offering them more personal autonomy and control over their health care decisions.

3. Philosophical congruence: Alternative therapies are attractive because they are seen as more compatible with patients’ values, worldview, spiritual/religious philosophy, or beliefs regarding the nature and meaning of health and illness.”

According to the survey results satisfaction, or lack thereof,  with conventional medicine did not correlate well with altmed use. 54% of respondents reported being “highly satisfied” with conventional medicine providers, of these 39% use alternative therapies. Of those who were highly dissatisfied (40%) only 9% were users of altmed.

It seemed as if those who were fans of medicine overall were more likely to participate in both camps. A sort of “the more the merrier” approach to health care.

What was predictive of alternative medicine use was personal philosophy. Those who considered there to be a strong mind/body/spirit connection as well as those who had had a “transformational experience” were more likely to use alt med than those who did not.

Education and health status also correlated with altmed use. Those with higher educations were more likely to use it, as were those who described themselves as having a lower health status.

The situation was slightly different for those who shunned conventional medicine altogether in order to embrace altmed. These folks tended to be distrustful of and dissatisfied with conventional practitioners, as well they desired a high degree of control over their health and believed in the importance and value of “inner experiences”.

This proportion of the population was quite small however – only 4.4% of the survey respondents fell into this group. Even so somehow the reasons for this group’s embrace of altmed has been generalised to the wider population.

The observation that users of altmed tend to be greater consumers of health services overall is also supported by the paper “Association Between Use of Unconventional Therapies and Conventional Medical Services“. This survey had a base of 16,068 individuals from which to pull data representing a 77% response rate from the 24,676 pool that was originally sampled.

According to this survey only 6.5% of the population use both altmed and conventional medicine** (and 1.8% using only altmed), with this group making more visits to their physician than those who used conventional medicine only. One possible reason for this is the so-called “worried well”, a portion of the population that focuses on their health to a degree higher than would be expected given their health status. Support for this is given within the paper:

“Compared with those with only conventional visits, those who used both types of care had significantly more outpatient physician visits (7.9 vs 5.4; P<.001), and used more of all types of preventive services except mammography. These groups did not differ significantly in inpatient care, prescription drug use, or number of emergency department visits.”

This on it’s own does not show a “worried well” connection but in the comments section of the paper it was noted:

“…there was no difference in any of the 4 self-reported health measures between respondents who had physician visits only, and those who had those visits in conjunction with unconventional therapy. Poor health status appeared to drive use of health services in general, that is, those using no services reported better health than those using either conventional medical services or unconventional therapies. However, poor health was not associated with increased use of unconventional therapies over and above conventional medical care.” [emphasis added]

So it would seem, at least in this sample, that dissatisfaction with conventional care cannot be the driving force for the majority of altmed users. More plausible is that altmed users seek to make the most of every perceived avenue for health.

Another survey published in 2001 also supported the general conclusion that dissatisfaction with conventional medicine does not lead to altmed use for most consumers. “Perceptions about Complementary Therapies Relative to Conventional Therapies among Adults Who Use Both: Results from a National Survey” surveyed 831 respondents who used both regular and alternative medicine.

Of these 70% would visit a conventional medicine practitioner as their first port of call. Only 15% went to a altmed provider first. There was also no significant difference in the level of confidence in altmed providers and regular medical professionals.

To quote the conclusion:

“National survey data do not support the view that use of CAM therapy in the United States primarily reflects dissatisfaction with conventional care.”

From a paper presented at the Proceedings of the 1997 Conference of
the Australian Association for Social Research and published in the Journal of Sociology; “Postmodern values, dissatisfaction with conventional medicine and popularity of alternative therapies“[PDF File download]:

“Those individuals who value natural remedies, are against chemical drugs, do not favour technological progress, and welcome variety in choice of therapy are more likely to have a positive attitude towards alternative medicine.”

These attitudes were enveloped under the “postmodern” rubric and were found to be a better predictor of altmed use than satisfaction levels with regard the conventional medicine.

To elaborate on that point, a further finding was that dissatisfaction with interactions with physicians rather than health outcomes was associated altmed use. This is a subtle point and worth dwelling on as it seems to be a valid criticism of the way in which conventional medicine is practised. It was not that altmed users were unhappy with the actual results of the care received via conventional medicines but the way in which they feel they are treated by doctors.

It seems that those turning to altmed may feel that conventional doctors do not give enough respect, time, don’t listen and are too authoritative. I don’t want to put too much emphasis on this perspective as it isn’t entirely consistent with the picture built up so far and the sample size of this survey was relatively small compared with the ones above (only 209 respondents), but it is worth considering.

In conclusion, while it might be true that some dissatisfaction does lead to an increase in the use of alternative medicine it seems unlikely to me that this is the main reason. I’m not sure why it has become the go-to reason trotted out by participants on both sides of the debate, ease I suppose. I could of course be wrong, perhaps there is a mountain of research out there that I’ve missed pointing in the complete opposite direction. I’m willing to grant that possibility, in the absence of such though I’ll have to go with personal philosophy being the largest contributing reason people use altmed.

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*I hate with a passion the label “Western Medicine”, what? – people from other cultures can’t use science? Nonsense.

** I suspect that the wildly differing definitions of what constitutes “Alternative” medicine are to be blamed for the fluctuating figures around the proportion of users.
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Astin, J. (1998). Why Patients Use Alternative Medicine: Results of a National Study JAMA: The Journal of the American Medical Association, 279 (19), 1548-1553 DOI: 10.1001/jama.279.19.1548

Eisenberg DM, Kessler RC, Van Rompay MI, Kaptchuk TJ, Wilkey SA, Appel S, & Davis RB (2001). Perceptions about complementary therapies relative to conventional therapies among adults who use both: results from a national survey. Annals of internal medicine, 135 (5), 344-51 PMID: 11529698

Druss, B. (1999). Association Between Use of Unconventional Therapies and Conventional Medical Services JAMA: The Journal of the American Medical Association, 282 (7), 651-656 DOI: 10.1001/jama.282.7.651

Siahpush, M. (1998). Postmodern values, dissatisfaction with conventional medicine and popularity of alternative therapies Journal of Sociology, 34 (1), 58-70 DOI: 10.1177/144078339803400106

Aditional reading:

Joy, J.M. (2004). Complementary and Alternative Medicine (CAM): Do Barriers to and Dissatisfaction with Traditional Care Affect CAM Utilization Patterns, Masters Thesis, Texas Tech University Health Sciences Center

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The Role of Experiments in Science


In an attempt to widen my horizons I have been listening to the Philosophy Now podcast out of the UK. A recent episode concerned philosophy of science (ep 29) and the host asked an interesting question: “Why do we have to have experiments when sometimes we can get away with observations?”.

The point he was trying to make was that when we think about science in an abstract way we also have the idea that experiments are at the core of the scientific method. This clashed somewhat with the person the host was talking with at the time who was emphasising observation as the way we confirm hypotheses in science.

The implication here is that we have two things, observations on the one hand and experiments on the other.

This appears to be a fairly common view, I have seen arguments accusing cosmology (specifically the big bang theory) of not being science because you can’t perform an experiment to create a new universe. Similar arguments have been made for evolution.

I don’t know how widely held this view is in the general population (as opposed to those who are set against certain findings of science) but the question of the podcast host implies that it’s wide enough.

The problem with this view however is that there really aren’t two things here that are different in kind. Rather, one is a sub-set of the other; experiments are a special kind of observation.

The whole point of an experiment is to interrogate nature in a specific kind of way. While we can passively observe an event and gain valuable information (say, watching the development of an embryo) we can also create an experiment that constrains the conditions in a particular way in order for us to draw more conclusive conclusions about the situation of interest (perhaps we knock out a gene and watch that embryo follow a different developmental path).

By using experiments we aren’t doing anything fundamentally different, we are still observing what nature has to tell us about the world we inhabit, but we are trying to set up conditions that are meant to clarify what nature is saying. In this view experiments are nature’s interpreter.*

Experiments also allow us to get access to things that we might not normally be able to see. For example high energy physics requires elaborate experiments in order to allow us to in some way visualise particles that are mind bogglingly small. We aren’t creating the physics we observe we are simply delving into realms that would normally be hidden from us.

This was brought home to me a few years back when the attempts to listen for extraterrestrial signals by SETI were referred to as experiments. In this case we aren’t setting up the conditions by which we control whether an ET sends us a signal, we are determining the conditions by which we would receive such a signal. At it’s heart this activity is an observation, no different in it’s intent from viewing a microbe under a microscope.

So it is that the ability to do or not do a experiment does not determine science from non-science (termed the demarcation problem and certainly not definitively settled). Experiments may have come to be thought of as the defining feature of science but they are really just a special case of something we all do every day – observe the world around us.

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*If that’s too narrow for you, how about experiments as nature’s speech therapist?

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The Freedom of Ignorance: Health Freedom, What is it and Do We Want it?


When policy around how herbal remedies, alternative medicines, supplements and all sorts of other practices outside the mainstream of medical practice is discussed the concept of “Health Freedom” inevitably comes up. It’s not always couched in that term but the idea is that people should be free to choose whatever method of healthcare that they wish.

Sounds good right? Who wants to impinge in someone’s freedom to make their own decisions? Isn’t that what living in a free country is all about? Personal autonomy, the right to take action unfettered by how someone else thinks I should run my life. That’s how I want to live, why should I want to take that away from others?

Well, I don’t. But the notion of freedom has always come with a caveat (several actually), that is – it is inherently restricted by ignorance. Is someone who is uninformed about the actual state of affairs truly free?

That’s what those who speak out about alternative medicine are actually trying to achieve. We aren’t attempting to “defend our turf” or “squelch the competition” we are attempting to inform the public about the true underpinnings of these therapies and point out they they are either unsupported by science or have in fact been disproved.

As has been noted before, a majority of New Zealanders are unaware that Homeopathic medicines do not contain any active ingredient and yet many people think they are scientifically proven.

Education was also the intent of the co-ordinated Sciblogs rebuttal to the poorly conceived and executed series on alternative therapies printed by the Herald earlier this year. (see here, here, here and here)

Policies that are aimed at restricting access to herbal or alternative medicine usually are doing so from the aspect of quality control. Does the remedy or practice have good evidence of efficacy, is it safe? These are the questions that we should be asking about every medical practice, not just those in the “alternative” (or complementary, or integrative, pick your marketing phrase of choice) camp.

Unfortunately is is not in the interests of those pushing alternative modalities to undergo strict evidence based testing so the issue is re-packaged from a quality control issue to a “freedom” issue.

Similar tactics are seen in arenas outside the medical realm. In biology the evolution vs creationism/intelligent design “debate” is framed as “Academic Freedom” as is the debate around climate change. This is not a coincidence. Whether or not these decisions are made consciously or not there has been convergence on the “Freedom” aspect of these cases for a reason, people respond to it. We are jealous of our freedom, and rightly so, freedom forms the basis of our society.

But as I alluded above, freedom is not an absolute and unalloyed good under all circumstances. It comes up against restrictions in all sorts of ways, some epistemological (as in the case of whether a choice is really free if the person is not aware of all the factors affecting that choice) and some are practical (as in should we allow freedom to include the freedom to sell harmful products?).

Conclusion

The natural/alternative remedies debate is not, at it’s heart, about freedom at all. Rather it is about education and quality control. We should subject all medical practices to the same rigorous examination regarding safety and efficacy. Long term “after market” monitoring should also factor into this equation to catch those practices that looked good in the necessarily limited testing that they are subjected to prior to being rolled out to the general public but may still have safety problems.

In this way we should be able to serve the public’s health interests and avoid false choices about freedom.

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Chiropractic for the 21st Century


Every week I get a number of email alerts about various online medical journals. Each email represents the opportunity for blogging material though many are deathly dull.

Several of the journals I receive alerts from are in the AltMed domain and I sometimes wonder why I bother looking through them at all. The mix is usually some proportion of “Survey of x population using y alternative modality” often merely chronicling the depressing rise of AltMed/CAM in general use (either actual or claimed depending on your definition of CAM).

The rest are often boringly conventional in their attempt to be scientific having titles like “Effects of vitamin E suplementation on renal non-enzymatic antioxidants in young rats submitted to exhaustive exercise stress“. These I don’t bother with. I just don’t have the expertise to parse them with any reliability.

Then there are the odd gems, either for comedic value or because they offer an alternative perspective on alternative medicine.

Recently one of the later came down the intertubes and into my in-box. Published in BioMed Central’s journal “Chiropractic & Manual Therapies”, the article is entitled “The Five Eras of Chiropractic & the future of chiropractic as seen through the eyes of a participant observer”.

The paper starts with a potted history of Chiropractic and the environment that it was founded and grew up in to the present. The early days could be seen as Chiropractic’s first opportunity to start down the science based path. In 1910 the “Flexner Report” on medical education was published and with it’s acceptance by the medical educational community came legitimation to those who abided by it’s recommendations. As well as:

…generous funding via the Rockefeller Foundation while schools that did not assent, simply ceased operation due to lack of funding. The result was that, by 1930, only 76 of the 168 medical schools remained.

The impact on Chiropractic is characterised thusly:

In part because of the rejection of science by a significant element within the chiropractic profession, and in part because the Flexner Report dismissed the chiropractors as “unconscionable quacks who should be dealt with by the public prosecutor and the grand jury”, the chiropractic profession bypassed the era of educational reform.

The early twentieth century therefore saw a great deal of animosity towards the nascent Chiropractic practice and the emerging scientific medicine of the time. Indeed the author argues that this conflict essentially shaped Chiropractic as we know it today. In order to defend Chiropractic from the legal attacks being made on it it was necessary to develop a definition of Chiropractic that would insulate it from charges of practising medicine without a licence, charges that were common against Chiropractors of the time.

This is related as involving four simple concepts:

1. Chiropractic is not medicine; chiropractic has a “separate and distinct philosophy and practice”.
2. Chiropractors do not diagnose, but analyze the spine for the  cause of dis-ease.
3. Chiropractors do not “treat,” but adjust the spine for the cause of dis-ease.
4. The Chiropractic profession has been built upon success in cases where medical doctors failed.

Putting aside the obvious sophistry in these concepts (how might we define the difference between diagnosis and “analyz[ing] … for the  cause of dis-ease” or between treatment and “adjust[ing] the spine for the cause of dis-ease“?) it is argued then that the very fact of opposition by the medical establishment helped to solidify the tenets and practice of Chiropractic:

During this journey, the chiropractic community developed and embraced a distinct lexicon and rationale toward health and its maintenance in order to emphasise the difference between medicine and chiropractic. Thus the “philosophy of chiropractic” became “an unyielding dogma”.

With this legal history at it’s back Chiropractic moved into the next period of it’s history where it was the focus of a co-ordinated and sustained attack by the medical establishment in the form of the AMA.

Carrying out the opposition to Chiropractic was the “Committee on Quackery”:

The Committee on Quackery was well funded, and operated a highly successful campaign that was centred on three main strategies:
1. An ethics based boycott, which deemed it unethical for AMA members to have professional dealings with chiropractors;
2. Convincing other organizations to adopt or adapt the AMA’s anti-chiropractic policy; and
3. Instituting a comprehensive political campaign to thwart chiropractic progress on several fronts, including but not limited to education, research and insurance funding.

This campaign was put to an end in 1987 thanks to a permanent injunction ordered against the AMA, after a lawsuit was levelled against it by a number of Chiropractors. At this point it’s difficult not to see the Chiropractic as a beleaguered philosophy deserving of empathy on behalf of it’s persecuted adherents.

Emerging from this legal victory Chiropractic has been slowly edging it’s way into mainstream acceptance with the development of Chiropractic based courses in universities and a surge in chiropractic research. Unfortunately the steadfast refusal of many Chiropractors to relinquish the unscientific concepts of old has meant that as a profession they are still looked upon with disdain:

Chiropractic’s problem is that subluxation based chiropractors are not only deluding themselves, they are indoctrinating patients into believing in a purportedly dangerous mythical entity, and that without regular adjustments, patients will not only fail to reach their full potential, they will likely suffer serious health problems.

Some authors have suggested that this may be a threat to public health . And this, at a time when the profession has just entered The Era of Chiropractic Opportunity.”

The opportunity discussed is that of the ever growing need for specialists in musculoskeletal care. As the worlds population ages the demand for providers who are proficient in the treatment of pack pain/musculoskeletal disorders will only increase.

It is into this world that the Chiropractic profession must be re-born as the evidence based providers of musculoskeletal care that are needed. The problem is that if Chiropractic insists on holding onto the non-scientific notions of DD Palmer then it voluntarily relegates itself to the back waters of medical practice.

This then is the proper focus of the article: where Chiropractic will go from here.

Least attractive to the author is the prospect that the practice will stay on it’s current trajectory, keeping the outdated concepts that it was founded upon and denying the very science that would confer upon them the legitimacy they crave.

Two options are given as alternatives to this “Status Quo” approach: one is to definitively split the profession into those that follow the traditional method of chiropractic practice, so-called “Straight Chiropractic”, and those who are willing to discard tradition and step into the light of science and evidence based practice.

The second and preferred option is to move forward with a united front, ditching along the way those parts of Chiropractic that are unsound and unproven. This is also recognised as the most difficult route for the profession, requiring near superhuman commitment from the individuals and organisations that make up the world’s Chiropractic profession:

Escaping from the dogma house will require extraordinary cooperation amongst all aspects of the profession. Organizations such as the World Federation of Chiropractic and all major chiropractic associations will need to agree upon and adopt a position statement identifying the chiropractic subluxation as an historical construct that remains a hypothesis, which cannot form the basis for patient care until and unless there is a body of scientific evidence to support it.

If the profession is to gain the trust of the consuming public it must, of necessity, become truly self-policing.

Only in this way will chiropractic generate the cultural authority required for recognition as a group worthy of the title “Profession”.

No longer can we cast a blind eye. By our silence we are giving consent.

Should Chiropractic refuse to move properly into the 21st Century then the consequences for it as a whole may be dire, leaving it’s future as a force in medical practice in doubt.

The chiropractic profession can choose to be illiterate, but it will do so at its peril. It is realized that thinking is hard and that those who are unaccustomed to thinking may even find it unpleasant. On the other hand, thinkers have always found it rather fun and there are no confirmed reports of anyone dying or being seriously injured by thinking. Thinking may necessitate changing our minds – which may not be a bad thing. At the very least the profession owes it to its patients.

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The Webwhisperer: A Medical Resource


I generally look with interest to see how people are getting to my blog. Often the referrer is Mr Google, the next culprit is usually Facebook, then there are pages where someone has posted a link to an article I written for others to check out. These are the most satisfying.

Sometimes it’s someone pointing out how stupid I am, many times I’m being used as a resource on some forum discussing AltMed. Today I found I was being linked to by a site called the Webwhisperer.

The Webwhisperer is a blog run by a UK doctor who is attempting to create a resource of reliable medical information, mainly for the doctor’s own family to access it seems but I think it has wider appeal and application.

Since the beginning of the year the Webwhisperer has been running a series on infant teething, the fifth and latest post is a link to my own article on Amber Teething Beads with a favourable intro. Ok, so I’m referred to as a mother but I’ll let that go (mainly because comments are disallowed and I can’t see any other way to contact the author. But also because I’m secure in my masculinity. Mostly).

Teething is something that can be quite distressing for new parents and is a topic that that every family member has an opinion on the best way to handle. A medical resource that gives factual information can be invaluable. So check it out.

There are many, many other topics covered on the site from allergies and alopecia to breast implants and pregnancy. I plan to browse it regularly. You should too.

God, UFOs, Life After Death: What do New Zealanders Believe?


Reading the paper today I learned that 1/3 of New Zealanders believe that we have been visited by extra terrestrials. I thought this was an interesting juxtaposition of stories given that a page or two later there was a report about a possibly habitable planet. Maybe aliens are visiting us from Kepler-22b.

Keplerites aside, I decided to look up the report from UMR Research about the beliefs of my fellow citizens.

The report makes for interesting reading (if somewhat disconcerting in places) and I’ll be looking for the follow-up reports around Maori culture and Herbal remedies. The first thing to note is that this was an on-line survey, so right off we should be wary about how representative these findings are of the general population. In that vein there was some attempt to make the results as representative as possible with quotas and weighting of responses. I couldn’t find details of how this was carried out so with that in mind do take the results with a grain of salt.

One of the first things that jumped out at me was how uncertain people were regarding their answers. The questions seems to have 4 possible answers for both the affirmative and negative, from Absolutely Certain through Fairly Certain, Not Too Certain and Not At All Certain.

So while 61% believe “That there is a God or some sort of universal spirit” only 28% are absolutely certain of this. If we lump in the fairly certains then it goes to 41% (from now on I’ll consider both groups to make up the “Certain” category). Compared to 38% who don’t believe (27% of who are certain-ish). 38% non-believers in NZ. It’s difficult to compare data sets but this appears to be up somewhat from ~34% (depending on how you count) religiously unaffiliated at the 2006 Census.

57% of us believe that there is life after death. 32% are certain. 31% are certain this isn’t the case. 55% of us believe in psychic powers, 27% are certain; 27% are certain that they don’t exist.

Now we get to the headline grabbing UFO question. 33% believe we have been or are being visited. How many are certain? 11%.

That’s a bit of a relief.

Then there’s Astrology. 24% think there is something to that malarkey. Only 6% are certain though. Whew…That’s lucky. Still, those horoscopes are everywhere.

It seems that the hardcore believers tend to only make up a minority of the population, even for the mainstream beliefs. With the more mainstream the belief the more evenly spilt the believers and non-believers. i call that interesting. As well as somewhat heartening.

The report breaks down the results further into gender and ethnic responses but I’m happy with looking at the top level stuff here. Check it out to see how women answered differently than men and how ethnicities are split between the different questions.

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Breaking News!: Have Constipation? Moxibustion Won’t Help!


ResearchBlogging.orgWhat’s Moxibustion, And why would you want to use it for constipation? The first I can answer, the second…not so much.

Moxibustion is the practice of burning ground up mugwort and applying the smouldering plant indirectly or directly to the skin to alleviate illness. In the indirect method acupuncture needles are inserted and the burning mugwort is used to heat either the skin or the needle. Direct methods are exactly what it sounds like, the mugwort is burned while sitting on the skin and your skin burns too. The amount of skin burning can vary – from minor to burns that will leave scars. On purpose.

Why would you want to subject yourself to this? Beats me.

But people do, and others study what it might be good for and publish papers about it. One of these turned up in my in-box this morning courtesy of BioMed Central Complementary and Alternative Medicine. With a title like “The effectiveness of moxibustion for the treatment of functional constipation: a randomized, sham-controlled, patient blinded, pilot clinical trial” how could I ignore it?

Reading the study I was transported to a place where the underlying physical process of disease matters not a whit and where the sweat, facial features, , body energy, duration of disease, and pulse type are methods of determining treatment. To be fair other measures were also used, including stomach pain, stuffiness and duration of disease.

No indication was given of how “body energy” was measured. Stuffiness was not defined – I’m sure these are standard things that every doctor knows about.

Frankly, if you are using a magical treatment to unblock your magical life energy then this is the type of thing you should expect to be important.

The study itself was quite small, as the title suggests, only 25 participants. 12 in the treatment arm and 13 in the sham moxibustion arm. Now, how do you do sham moxibustion? Apparently, as it is the heat from burning the mugwart that is important, you just introduce an insulator to stop that heat reaching the patient.

Luckily the procedure used was the indirect acupuncture type, so those in the sham group didn’t wonder why no third degree burns where in evidence.

This approach leaves all the burny, smokey goodness of the mugwort though. Given the negative outcome of the study I suspected this would come up in the discussion. I was not disappointed.

We’ll get to that in a bit. First I want to cover how the patients were divided into “deficiency syndromes” and “excess syndromes”. Constipation in traditional Chinese and Korean medicine is apparently due to either a deficiency or excess of qi (chi), you know, the life energy. This is where checking out people’s faces and sweating etc comes in.

I’ll quote directly from the paper at this point:

“A patient with a deficiency syndrome has sunken, weak pulse, whereas a patient with an excess syndrome has superficial and broad pulse. The patients having symptoms such as a pale face, heavy sweat, and depression were considered to have a deficiency syndrome; the patients having symptoms such as a swollen face, little sweat, and chest pressure were considered to have an excess syndrome. Syndrome pattern differentiation was conducted by an OMD before randomization.”

Further on:

“Five participants were diagnosed with an excess syndrome, and twenty-one participants were diagnosed with a deficiency syndrome. In this study, the most prevalent symptoms for an excess syndrome were a strong body energy and superficial pulse; for a deficiency syndrome the symptoms were a long duration of disease and weak body energy.”

Given that “body energy” plays such a part in dividing the patients I was hoping at this point it would be defined and a method to assess it given. Alas, I was out of luck. Obviously it’s too basic to explain here.

To the results!

I already gave the game away: moxibustion was no different than sham moxibustion when it comes to improving symptoms of constipation. To their credit the authors admitted this could be because moxibustion is, in fact, ineffective. But then, maybe they chose the wrong acupuncture points (never mind that large well designed studies show that where you stick the needles has no effect on outcomes). Or perhaps the sample size was too small – I’ll give them this one, though if there was a significant effect then even a small sample should have shown it.

Then the inevitable, perhaps the sham moxibustion was effective after all. Because, you know, the smoke and stuff. And, oh yeah, the patients actually had “excess-cold” syndromes when normally you’d expect excesses to be warm – so maybe that has something to do with it…

Can you say “rationalising”?

The authors also note that while a number of adverse events have been reported for moxibustion, the patients in this group only experienced redness. Another quote:

“Previously reported adverse events related to moxibustion treatment include burns [no kidding, I thought that was a feature - not a bug], an itching sensation, infection, allergy and xerophthalmia [dry eyeballs]“

Dry eyeballs…. hmmm, better than a punctured lung.

The paper concludes with the obligatory call for larger more rigorous studies, despite the fact that this is an implausible treatment based on magical thinking. Oh well, such is the way of things nowadays.
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Park JE, Sul JU, Kang K, Shin BC, Hong KE, & Choi SM (2011). The effectiveness of moxibustion for the treatment of functional constipation: a randomized, sham-controlled, patient blinded, pilot clinical trial. BMC complementary and alternative medicine, 11 (1) PMID: 22132755

Confounding Variables


Over at Psychology in Action there’s a decent post on confounding variables.

The focus is on conducting and reading research and determining good research study practice but I think there is value in everyone knowing what confounding variables are.  So what are they?

Well, read that post……

Ok, good.

Another example that I got in my stats class (many moons ago) was the correlation of matches with cancer. Those people who tend to carry boxes of matches in their pockets also have a higher risk of cancer.

As in the Murder vs Ice-cream example given at the link above, there is no direct link between matches and cancer (though it’s obviously related), the most probable explanation is that those who carry matches are more likely to be those who smoke and it is the smoking that relates to cancer.

Smoking can then be said to be the confounding variable – the variable that explains both of the explicitly stated variables and either ties them together with a causal mechanism (Matches -> Cancer) or shows that there is no direct relation (Ice-cream -/-> Murder).

A similar effect may be seen with something like surveys, the manner in which a survey is carried out may introduce confounding variables (say a phone or internet survey which pre-selects participants by their access to said communication methods) or the questions asked may smuggle in assumptions that do not separate out confounding variables.

For example a survey may ask “Are you Religious” and “Are you Happy” (as many have). The Religious question smuggles in a number of extra factors that may contribute to a person’s level of happiness eg religions usually come with a feeling of belonging to a community, social interaction, social support networks or guilt over actions and feelings. Each of which may more directly impact happiness that religion per se.

Other areas may also suffer from the confounding variable problem, alternative medicine springs to mind. Say you suffer from a cold, you soldier through it until you can’t take it any more and start downing some homeopathic remedy. In a day or two your symptoms resolve and you feel better. Did the remedy work?

In this case the confounding variable could be the natural history of the disease. Colds don’t last for ever (it is “self limiting”), it could be that you took the remedy right before the cold would have resolved itself anyhow. If this is so the conclusion that the remedy “cured” your cold would be invalid, there would not be a causal connection between the remedy and the cold symptoms going away.

The natural history of the disease would explain the reason you took the remedy when you did (symptoms had reached a climax) and why the remedy appeared to work (the cold would have resolved anyway).

When we examine issues closely we can see that confounding variables crop up, and should be carefully considered, every time we try to determine a causal connection between two events or phenomena. This is the reason that skeptics chant “Correlation does not equal causation” like a mantra.

Just for fun, suggest some instances of confounding variables in the comments. The more obscure the better.

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