Systematic reviews and meta-analyses on treatment of asthma: critical evaluation
Hard pressed doctors trying to cope with the vast amounts of information on new treatments for asthma would do well to turn to the Cochrane reviews rather than those published in peer-reviewed journals or funded by industry. The Cochrane reviews are more rigorous and better reported than those published in peer review journals, says an article in this week's BMJ. All six of the reviews sponsored by industry were found to have serious methodological flaws and five out of six had results that favoured interventions related to the companies sponsoring the reviews.
Alejandro Jadad et al of the Department of Clinical Epidemiology and Biostatistics at McMaster University in Hamilton, Canada subjected 50 clinical reviews to critical evaluation using the Oxman and Guyatt index to measure methodological quality. Of the 10 highest scoring reviews, seven were published in the Cochrane Library. Dr Jadad, who declares a competing interest as co-director of the Canadian Cochrane Network and Centre, says most of the reviews had methodological limitations which could easily have been avoided. He recommends that peer reviewed journals provide authors and peer reviewers with clear reporting criteria and use the Internet to update or correct previously published material. Industry sponsored research demands particular vigilance, the authors conclude.
Contact:
A R Jadad, Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada L8N 3Z5 Email: jadada@fhs.mcmaster.ca