Randomised clinical trials are often inadequately reported and may be inadequately conducted. Any associated biases could impact seriously on the findings and conclusion of a systematic review. Authors of systematic reviews thus need to assess the risk of bias in included randomised clinical trials. In this 20th Anniversary editorial, we look at the evolution of guidance on appraising studies included in Cochrane Reviews.
The Cochrane Collaboration has become a lead partner in the AllTrials initiative (AllTrials.net), a campaign to ensure that all clinical trials are registered and the results reported, for all treatments in current use. Cochrane joins Sense About Science, Bad Science, the BMJ, the James Lind Initiative, and the Centre for Evidence Based Medicine in leading this international campaign, which has already signed up over 200 research bodies, regulators, and patient groups, and nearly 50,000 individuals. This, though, is just a beginning.
In reflecting on his career, Archie Cochrane once said that he felt it was a pity that he was mainly remembered for his work on randomised controlled trials. He actually felt more proud of the research he had done on behalf of workers in British coal mines. Based on his work, dust levels in coal mines have been lowered considerably, reducing the risk of pneumoconiosis. There have been improvements in many other occupational safety and health statistics, such as injury rates and exposures to chemical agents, but there are also OSH problems for which the statistics have not shown a decline.
The leishmaniases are a group of diseases caused by infection with protozoan parasites of the genus Leishmania. They affect the poorest of the poor and are associated with malnutrition, wars, displacement, poor housing, illiteracy, gender discrimination, lack of resources, and environmental changes.