title: Assessment of changes to screening programmes: why randomisation is important.
authors.affiliation: Centre for Research in Evidence Based Practice, Bond University, QLD 4229, Australia katy.bell@sydney.edu.au.
authors.forename: Katy J L
authors.initials: KJ
authors.lastname: Bell
authors.affiliation: AMC, Amsterdam, Netherlands.
authors.forename: Patrick
authors.initials: P
authors.lastname: Bossuyt
authors.affiliation: Centre for Research in Evidence Based Practice, Bond University, QLD 4229, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Glasziou
authors.affiliation: Screening and Test Evaluation Program, School of Public Health, University of Sydney, Australia.
authors.forename: Les
authors.initials: L
authors.lastname: Irwig
mesh_terms: D006801:Humans; D008403:Mass Screening / Q000379:methods / Q000592:standards; D011897:Random Allocation; D012107:Research Design