Key research papers 'misleading'

Reviews help doctors decipher complex research

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.

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."