No one will be surprised to learn one of the conclusions in a report on
scientific publication bias by the AMA's Council on Scientific Affairs: money
matters in research.
The report, issued at last month's House of Delegates meeting in Chicago,
states that "studies with positive findings are more likely to be
published than studies with negative or null results, and an association
exists between pharmaceutical industry sponsorship of clinical research and
publication of results favoring the sponsor's products."
Additionally, the publication of negative results may be delayed compared
with the time to publication of studies with positive results. This relative
time lag is not limited to industry-sponsored trials.
The council conducted a literature search of articles published between
1985 and 2003 and identified 12 systematic reviews on the relationship between
pharmaceutical-industry sponsorship and research outcome, quality, or
publication bias. Three of these reviews evaluated previously published
information on the relationship between industry funding and outcome or
quality; more than 2,000 original studies were included in the original
studies covered by these reviews.
Four sources of bias were identified: investigators and authors, journal
editors and reviewers, clinical-trial agreements, and outcome bias.
"When control lies with the commercial rather than academic or public
sector, bias can also envelop the process through the trial design," the
report stated. "Outcome bias can result from the use of unreliable
methods or instruments, as well as inadequate sample size or comparison
On the basis of the findings, the Council on Scientific Affairs recommended
The council's report, "Influence of Funding Source on Outcome,
Validity, and Reliability of Pharmaceutical Research," is posted online