Tuesday, April 02, 2013

Discussions about NCCAM's chelation study (TACT)

Cardiobrief has posted an update. What amazes me about these discussions is that anyone would take TACT for more than entertainment value. Equally amazing is that JAMA, which is supposed to be a top level journal, would give it the time of day. (Would they loosen their standards in kind for Pharma sponsored trials? Don't think so). The irony is that what some would consider a lower tier journal, the Medscape Journal of Medicine, had the most scientifically rigorous perspective on the trial. (See also here).

At least JAMA did publish one appropriately critical editorial---that of Steven E. Nissen, MD. In it Nissen echoed precisely a concern I expressed several years ago in my Magical Mystery Tour of the TACT study sites when he said:

Execution of a high-quality RCT requires skilled investigators and study coordinators who understand these critical scientific principles. For TACT, more than 60% of patients were randomized at enrolling centers described as complementary and alternative medicine sites. Many of these centers have websites that describe their services, which include an array of unproven therapies ranging from stem cell therapy to regrow breasts after mastectomy, high-dose intravenous vitamin C to treat cancer, and use of cinnamon for treating diabetes to treatment of influenza with antimicrobial essential oils or homeopathic remedies (while warning patients not to undergo immunization). Other sites offer chelation to treat or cure a variety of conditions including autism in children. A common theme of these centers is evident—they appear to attempt to appeal to vulnerable patients who have challenging diseases by offering a variety of unscientific and unproven therapies. Whether a high-quality RCT can be performed at such sites is questionable.

A missing element in most of these discussions is whether, before TACT was even conceived, chelation therapy as a remedy for atherosclerotic disease even deserved further study. It didn't.

Finally, the author or the Cardiobrief piece gave this little shout out to Orac:

The most sustained assault on TACT, and on Krumholz’s position, comes from the highly-regarded skeptic blog Respectful Insolence written by Orac (the pseudonym of David Gorski, a surgical oncologist). In his take-no-prisoners assault on TACT, JAMA, and Krumholz, Orac writes “that JAMA is every bit as guilty as The Lancet was in 1998 when it published Andrew Wakefield’s antivaccine nonsense…. If published at all, TACT should have been published in some crappy, bottom-feeding journal, because that’s all that it deserves.”

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