Clinical Research Findings Often 'Biased Or
Incomplete'
June 1, 2004
Clinical research cannot be taken
at face value because findings are often made public in a biased or incomplete
way, a new report says.
University of Oxford academics
found that some clinical trial findings were simply not reported.
Other trials changed tack once the
results had begun to emerge.
The Oxford researchers analysed
the published results of over 100 clinical trials.
They found that almost two thirds
of results relating to potentially harmful trial outcomes were not fully
reported.
And half of results relating to
the effectiveness of the treatment on trial were not fully made public.
The research found that many
studies changed tack after they had got under way, failing to stick to the
original aims set out in the research protocol.
In 62% of cases at least one primary outcome had been changed, introduced, or
omitted after the trial got under way.
Researcher Dr Douglas Altman, a
professor of statistics in medicine at the Institute of Health Studies,
Oxford, said: “The problem is really in things which are not being reported.
It is not a criticism of things in the publications. There is a tendency to
withhold the less interesting stuff.”
“It is part of the same picture.
There is a tendency, to use modern jargon, of putting a positive spin on
it.”
Eighty-six percent of the clinical
trial teams contacted about the findings denied the existence of unreported
outcomes, despite clear evidence to the contrary.
The study did not show the reasons
why scientists changed research focus – or why certain findings were not
made public.
Dr Altman said; “What we found
was that in an appreciable number of cases there were discrepancies between
what they said they would do and what they had actually done. Whether there is
anything sinister in that is very hard to tell.”
The Oxford research found no
evidence that commercially sponsored trials were reported more or less
accurately than their independently-funded counterparts.
Dr Altman said his team’s
findings, published in the Journal of the American Medical Association, should
not undermine the veracity of clinical trials.
“It is a bit worrying but I
personally wouldn’t at all want people to start distrusting medical research
on the basis of our study,” he said.
The research team is calling for
proposed new trials to be registered, with their aims and methodology made
public.
Dr Altman and Dr An-Wen Chan,
Oxford University clinical researcher, teamed up with researchers from the
Nordic Cochrane Centre in Denmark for their project.
Source: Scotsman, 01/06/2004
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