corner
Healthy Skepticism
Join us to help reduce harm from misleading health information.
Increase font size   Decrease font size   Print-friendly view   Print
Register Log in

Healthy Skepticism Library item: 20482

Warning: This library includes all items relevant to health product marketing that we are aware of regardless of quality. Often we do not agree with all or part of the contents.

 

Publication type: Journal Article

Vedula SS, Li T, Dickersin K
Differences in Reporting of Analyses in Internal Company Documents Versus Published Trial Reports: Comparisons in Industry-Sponsored Trials in Off-Label Uses of Gabapentin
PLoS Med 2013 Jan 29; 10:(1):
http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1001378


Abstract:

Background

Details about the type of analysis (e.g., intent to treat [ITT]) and definitions (i.e., criteria for including participants in the analysis) are necessary for interpreting a clinical trial’s findings. Our objective was to compare the description of types of analyses and criteria for including participants in the publication (i.e., what was reported) with descriptions in the corresponding internal company documents (i.e., what was planned and what was done). Trials were for off-label uses of gabapentin sponsored by Pfizer and Parke-Davis, and documents were obtained through litigation.

Methods and Findings

For each trial, we compared internal company documents (protocols, statistical analysis plans, and research reports, all unpublished), with publications. One author extracted data and another verified, with a third person verifying discordant items and a sample of the rest. Extracted data included the number of participants randomized and analyzed for efficacy, and types of analyses for efficacy and safety and their definitions (i.e., criteria for including participants in each type of analysis). We identified 21 trials, 11 of which were published randomized controlled trials, and that provided the documents needed for planned comparisons. For three trials, there was disagreement on the number of randomized participants between the research report and publication. Seven types of efficacy analyses were described in the protocols, statistical analysis plans, and publications, including ITT and six others. The protocol or publication described ITT using six different definitions, resulting in frequent disagreements between the two documents (i.e., different numbers of participants were included in the analyses).

Conclusions

Descriptions of analyses conducted did not agree between internal company documents and what was publicly reported. Internal company documents provide extensive documentation of methods planned and used, and trial findings, and should be publicly accessible. Reporting standards for randomized controlled trials should recommend transparent descriptions and definitions of analyses performed and which study participants are excluded.

 

  Healthy Skepticism on RSS   Healthy Skepticism on Facebook   Healthy Skepticism on Twitter

Please
Click to Register

(read more)

then
Click to Log in
for free access to more features of this website.

Forgot your username or password?

You are invited to
apply for membership
of Healthy Skepticism,
if you support our aims.

Pay a subscription

Support our work with a donation

Buy Healthy Skepticism T Shirts


If there is something you don't like, please tell us. If you like our work, please tell others.

Email a Friend








Cases of wilful misrepresentation are a rarity in medical advertising. For every advertisement in which nonexistent doctors are called on to testify or deliberately irrelevant references are bunched up in [fine print], you will find a hundred or more whose greatest offenses are unquestioning enthusiasm and the skill to communicate it.

The best defence the physician can muster against this kind of advertising is a healthy skepticism and a willingness, not always apparent in the past, to do his homework. He must cultivate a flair for spotting the logical loophole, the invalid clinical trial, the unreliable or meaningless testimonial, the unneeded improvement and the unlikely claim. Above all, he must develop greater resistance to the lure of the fashionable and the new.
- Pierre R. Garai (advertising executive) 1963