Friday, September 24, 2010

More Mark Crislip

If you have not YET started following http://www.sciencebasedmedicine.org/, you must take the leap today.

The title of the blog will be familiar to people who happen to follow any of Mark Crislip's sites/offerings.  He is a podcaster (QuackCast, Gobbet o' Pus) and a blogger (at ScienceBasedMedicine.org, MedScape, etc.) among other things.  He often states that the world needs more Mark Crislip (I tend to agree) and "More Mark Crislip" is the name of his main website (http://moremark.squarespace.com/).

He has a recent entry on SBM (ScienceBasedMedicine) that he calls "Short Attention Span SBM" that includes an update and some information on vitamin D, influenza and (as copied below) acupuncture:

Acupuncture

“Man is the only animal that blushes. Or needs to. –Mark Twain

Acupuncture is all placebo effect, what ever that is. This was re-confirmed in “A randomized controlled trial of acupuncture for osteoarthritis of the knee: Effects of patient-provider communication“.

In this trial, patients had real acupuncture or sham acupuncture (as if there is a difference) and they had neutral or enthusiastic acupuncturists.

Those that had an enthusiastic acupuncturist had a better decrease in reported pain, whether the acupuncture was real or sham.
TCA was not superior to sham acupuncture. However, acupuncturists’ styles had significant effects on pain reduction and satisfaction, suggesting that the analgesic benefits of acupuncture can be partially mediated through placebo effects related to the acupuncturist’s behavior.
This result is of no surprise. Expectations will often color peoples perceptions. More expensive wine is rated higher than the same vintage labeled as cheaper. An expensive placebo is more effective than an cheap placebo.

But does perception of reality mean reality was altered?

I play golf with my kids almost every night in the summer and towards the end of the season I get right elbow tendinitis. As I make my downswing the pain fibers fire and can mess up my swing if I am not focused on hitting through the pain. If I take 400 milligrams of ibuprofen before I play, I have less pain and my swing is unchanged. Not enough to beat my son, but that is another matter.

Decreasing pain leads to improved function when pain limits function. If you have a musculoskeletal problem, you usually have a reproducible limit to your function due to the pain. If the pain is decreased, the function should improve.

As I have discussed at length, I do not think there is really a placebo effect. Certainly for objective endpoints, there is no placebo effect. Buried in the acupuncture paper were two objective end points: range of motion and the Timed Up and Go Test. For objective endpoints there were no changes in any of the groups. So it makes me wonder just what improvement these patients ‘really’ had. Subjectively better, objectively no change.

Is the placebo effect no more than a patient convincing themselves they are better when in fact nothing has changed? That is my interpretation. If function is not improved, if they are still limited by pain, is the pain really gone? Is this response a milder example of the same cognitive processes that can lead to hysterical blindness or not seeing tumors the size of a large mushroom? Man is the only animal with the ability to convince themselves that the tangible is unreal or that the unreal is tangible.

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