Reviews
which combine the results of important research studies often
contain errors or omissions, say experts.
Often,
individual studies can produce varying results, and such reviews
- often by leading figures in the specialty - aim to draw
together an overall conclusion from them.
Reviews
help doctors decipher complex research
They can be influential in how ordinary doctors use research
to change the way they treat their patients, because they mean
that the doctor does not have to wade through scores of complex
research studies to reach a conclusion.
But researchers from two universities in the US, using reviews
written on an important area of diabetes research, say important
findings were missed out.
"Review
articles, particularly those written by specialists, tend
to be of dubious value, with authors selectively choosing
evidence to support their own prejudices" --- Dr David Fitzmaurice,
University of Birmingham
Many studies have been carried out into treatment of type II
diabetes - and the US experts looked to see whether reviews
took into account the findings of just one of them.
This was a massive study, carried out in the UK, which found
that keeping blood pressure tightly under control was important
in maintaining the overall health of patients.
However, of 35 reviews into type II diabetes, all of which claimed
to have included the UK research in their deliberations, only
six mentioned this key finding.
Another key finding of the UK research, which found that a particular
drug cut deaths, was only mentioned in seven of the reviews.
Misleading
Physicians around the world relying on such reviews for information
about new research would be misled by them, say the researchers.
"We found that the results of the most important research in
diabetes in the past 25 years was incompletely and often inaccurately
transmitted to readers," they wrote in the British Medical Journal.
Remarkably, they found that the degree of accuracy of the review
was related to the prominence of its author - the more well-known
the author, the worse the review.
Dr David Fitzmaurice, from the Department of Primary Care and
General Practice at the University of Birmingham, said it was
well-known that reviews could be misleading.
"Review articles, particularly those written by specialists,
tend to be of dubious value, with authors selectively choosing
evidence to support their own prejudices," he said.
"We should perhaps question why these expert reviews continue
to be published, given both their lack of rigour and their apparent
lack of influence."
Often,
individual studies can produce varying results, and such reviews
- often by leading figures in the specialty - aim to draw
together an overall conclusion from them.
