26 Aug 2010


But people who draft management guidelines are conscientious and world-renowned experts. They would not allow their potential conflicts of interest interfere with their judgment and recommendations, right?

Yes and no. I tend to trust that most guidelines reflect what the authors believe and are not for financial and political gains. Nevertheless, the recommendations can still be biased. In our field, colonoscopy surveillance for colorectal cancer prevention is a big business. In some countries, there are clinicians who would call themselves colonoscopists, more or less telling you that they would not do much else. However, one cannot ignore the fact that the effect of colonoscopy surveillance on overall and cancer-related mortality has not been tested by randomized controlled trials. In addition, there is accumulating evidence to show that colonoscopy does not save more lives than flexible sigmoidoscopy, a simpler procedure that does not require thorough bowel cleansing and sedation, not to mention the lower complication rate.

With this background, you probably would expect that experts should support the simpler procedure. Nevertheless, searching through the literature, many experts (notably gastroenterologists) still state colonoscopy as the preferred surveillance method.[N Engl J Med 2009;361:1179-87] The rationales such as more thorough examination and the inclusion of proximal colon are more theoretical than evidence-based. Again, in this particular case I do not doubt the experts recommend colonoscopy for their own benefits. They are so senior that I cannot imagine they are still making a living by doing endoscopies. The biased view merely stems from their background and thus health beliefs.

Therefore, the medical committee is suggesting a revisit of the guideline drafting process. In essence, experts in one particular field should mainly provide relevant evidence but not have overwhelming influence on the final recommendation statements.

P.S. If you search PubMed for articles on CT colonography, it would be funny to note that around half of the articles said that this new radiological technique is extremely good and half said its performance is suboptimal and not ready for routine clinical use. If you note the affiliations of the first authors, the former articles were all written by radiologists and the latter were by, you got it, gastroenterologists. This time, we are talking about real business.


  1. So....... Are we doing business or research? I am confused.

  2. Guidelines are just for the public. Just ask what will you choose if that was your father.