Friday, January 18, 2008

Have the Peddlers of Antidepressants (Big Pharma) been Successful in Suppressing Negative Trial Results?

Yes, according to this article in yesterday's NEJM:
http://content.nejm.org/cgi/content/short/358/3/252

Talk about publication bias. According to Erick H. Turner, M.D. and coauthors, the selective publication of only "positive" trials, in addition to publishing in a positive light studies that the FDA considered "negative" leads to a 32% increase in the apparent efficacy of antidepressant drugs, on average (range 11-69%). Once again, profit trumps science, safety, and patient and public health.

What can we do about it? First, reduce by one third the effect size of any antidepressant results you see in an industry-sponsored clinical trial. Next, carefully consider whether whatever [probably modest] effect remains is worth the side effects (e.g., increase in suicide), cost, and nuisance of the drug. Third, prescribe generic agents. Fourth, don't allow pharmaceutical reps to speak with you about new products. Fifth, consider alternative treatments.

I am reminded of a curious occurrence relating to a drug that I think is definately worth the cost, side effects, and nuisance associated with it: Chantix (varenicline) - Pfizer's smoking cessation drug. In JAMA in July 2006,
(http://jama.ama-assn.org/content/vol296/issue1/index.dtl)
two nearly identical articles described two nearly identical studies, which shared many of the same authors. What was the intent of this? Why not conduct one larger study? Was the intent to diversify the risk of failure and allow for selective publication of positive results? I'm very interested in any information anyone can provide about this curious arrangement, which appears to be without precedent. Please leave your comments below.

6 comments:

  1. Here is another relevant like relating to the effect of "grey literature" on point estimates of treatment effects in meta-analyses:

    http://www.thelancet.com/journals/lancet/article/PIIS0140673600027860/abstract

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