Archive for May 28th, 2009

Homeocracy IV

In the three prior posts of this series I tried to analyze some of the defects in the randomized clinical rials (RCTs) of homeopathic remedies for childhood diarrhea. The first entry showed that the first two RCTs’ (done in Nicaragua) methods could not produce a meaningful result because of the way the RCTs were set up (methods.) The second entry showed that the results obtained in the first two trials were meaningless clinically even if assumed to have resulted from more legitimate methods. The same applied to the third trial in Nepal, analyzed in the third entry.

This entry  will suggest that the authors’ fourth paper (Jacobs J, Jonas WB, Jimenez-Perez M, Crothers D. Homeopathy for childhood diarrhea: combined results and metaanalysis from three randomized, controlled clinical trials.  Pediat Inf Dis J, 2005;22:229-234.)- a meta-analysis (MA) of the data from the three RCTs resulted in conclusions equally as meaningless as those of the three trials.

The MA authors – several of the same workers from the three RCTs – begin by agreeing that the data from the RCTs, taken individually, were of borderline significance:

In our previous three studies, we evaluated the use of individualized homeopathic treatment of childhood diarrhea … The results of the two larger studies (n = 81, n = 116) were just at or near level of statistical significance. Because all three studies followed the same basic study design , […] we analyzed the combined data from these three studies to obtain greater statistical power.  In addition we conducted a meta-analysis of effect-size difference […] to look for consistency of effects.

MAs and systematic reviews (SRs) are the two consensus methods for summarizing data from multiple individual studies. The inclusion and search methods of RCTs for SRs and MAs are similar, but the objectives of the two are a bit different, as are the forms of the reports.  In SRs, the results are summarized  in more in narrative form, whereas in MAs the data are treated mathematically and the results are defined in statistical terms.  Thus authors of SRs are freer to speculate on the degree of confidence that a method is effective based on what is shown by the numbers of positive and negative RCTs collected.  Authors of MAs usually limit their comments to what the mathematical formulation of the summarized data show.

Posted in: Clinical Trials, Energy Medicine, General, Homeopathy, Science and Medicine

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Science And The Game Of 20 Questions

An audience member at a recent NYC Skeptics meeting asked me how I handled conflict surrounding strongly held beliefs that are not supported by conclusive evidence. As a dentist, he argued, he often witnessed professionals touting procedure A over procedure B as the “best way” to do X, when in reality there are no controlled clinical trials comparing A and B. “How am I to know what’s right in these circumstances?” He asked.

And this is more-or-less what I said:

The truth is, you probably can’t know which procedure is better. At least, not at this point in history. The beauty of science is that it’s evolving. We are constantly learning more about our bodies and our environment, so that we are getting an ever-clearer degree of resolution on what we see and experience.

It’s like having a blurry camera lens at a farm.  At first we can only perceive that there are living things moving around on the other side of the lens – but as we begin to focus the camera, we begin to make out that the animals are in the horse or cattle family. With further focus we might be able to differentiate a horse from a cow… and eventually we’ll be able to tell if the horse has a saddle on it, and maybe one day we’ll be able to see what brand of saddle it is. Each scientific conundrum that we approach is often quite blurry at the onset. People get very invested in their theories of the presence or absence of cows, and whether or not the moving objects could in fact be horses. Others say that those looking through the camera contradict one another too much to be trusted – that they must be offering false ideas or willfully misleading people about the picture they’re describing.

In fact, we just have different degrees of clarity on issues at any given point in time. This is not cause for alarm, nor is it a reason to abandon our cameras. No, it just gives us more reason to continue to review, analyze, and revise our understanding of the picture at hand. We should try not to make more out of photo than we can at a given resolution – and understand that contradicting opinions are more likely to be evidence of insufficient information than a fundamental flaw of the scientific method.

Posted in: General, Science and Medicine

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