Medical Journals Are an Extension of the Marketing Arm of Pharmaceutical Companies

From this article in PLoS Medicine:

By 2003 it was possible to do a systematic review of 30 studies comparing the outcomes of studies funded by the pharmaceutical industry with those of studies funded from other sources [8]. Some 16 of the studies looked at clinical trials or meta-analyses, and 13 had outcomes favourable to the sponsoring companies. Overall, studies funded by a company were four times more likely to have results favourable to the company than studies funded from other sources. In the case of the five studies that looked at economic evaluations, the results were favourable to the sponsoring company in every case.

The evidence is strong that companies are getting the results they want, and this is especially worrisome because between two-thirds and three-quarters of the trials published in the major journals—Annals of Internal Medicine, JAMA, Lancet, and New England Journal of Medicine—are funded by the industry [9].

They also list some ways in which pharmaceutical companies, which are in some respects held to higher standards than academic labs, manipulate data:

Examples of Methods for Pharmaceutical Companies to Get the Results They Want from Clinical Trials

Conduct a trial of your drug against a treatment known to be inferior. Trial your drugs against too low a dose of a competitor drug. Conduct a trial of your drug against too high a dose of a competitor drug (making your drug seem less toxic). Conduct trials that are too small to show differences from competitor drugs. Use multiple endpoints in the trial and select for publication those that give favourable results. Do multicentre trials and select for publication results from centres that are favourable. Conduct subgroup analyses and select for publication those that are favourable. Present results that are most likely to impress—for example, reduction in relative rather than absolute risk.