title: Bias due to changes in specified outcomes during the systematic review process.
authors.affiliation: Centre for Medical Statistics and Health Evaluation, University of Liverpool, Liverpool, England. jjk@liv.ac.uk
authors.forename: Jamie J
authors.initials: JJ
authors.lastname: Kirkham
authors.forename: Doug G
authors.initials: DG
authors.lastname: Altman
authors.forename: Paula R
authors.initials: PR
authors.lastname: Williamson