Monday 7 May 2012

RF: a harmful placebo


RF (Radio Frequency, or Radio Frequency Ablation) is used widely. The idea is that a probe is inserted into the affected area which then emits a radio frequency that “changes” (read: damages) the local tissues. It is used in the spine, the shoulder, the wrist and even for liver tumours.

The story with this is so similar to my previous blogs that many of you may be able to fill in the rest of this one for me. In fact, for things like this I should develop a standard blog template to cut and paste in the future. Something like this:

[PROCEDURE NAME] is a treatment that is widely used for a variety of different conditions. The mechanism by which it is assumed to achieve the desired effect sounds biologically plausible. It is high-tech and expensive and many doctors recommend it. It has been tested in the laboratory where [PRODUCT NAME] has been shown to achieve changes in cells and animals that support the biological explanation. Early studies in humans show promising results.

However, clinical studies that have compared [PRODUCT NAME] to a placebo in a randomised trial are few, and while studies that were supported by [COMPANY NAME] are positive, independent studies have not shown a clinically important difference between [PRODUCT NAME] and the placebo.

Now insert “RF” for “PRODUCT NAME” above, follow these links (here, here and here) for some of the evidence, and you are beginning to get the picture. Even the most supportive study does not fill me with hope.

To complete the picture for RF though, I need to give you some more information. Remember that my recurring theme is how doctors (and the public) tend to overestimate the benefit AND underestimate the harm of treatments? So what are the harms of RF? Follow these links (here, here, and here,), and if my argument about the ineffectiveness of RF didn’t convince you, these reports of harms might. I particularly like the last link where, after providing a long list of major complications from RF, including a few deaths, the authors conclude, “RF ablation is a relatively low-risk procedure”. No level of harm is acceptable without good evidence of a benefit, against which we might balance the harm.

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