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dc.contributor.authorSiontis, K. C.en
dc.contributor.authorEvangelou, E.en
dc.contributor.authorIoannidis, J. P.en
dc.date.accessioned2015-11-24T19:05:46Z-
dc.date.available2015-11-24T19:05:46Z-
dc.identifier.issn1464-3685-
dc.identifier.urihttps://olympias.lib.uoi.gr/jspui/handle/123456789/20239-
dc.rightsDefault Licence-
dc.subjectAnalysis of Varianceen
dc.subject*Bibliometricsen
dc.subject*Clinical Trials as Topicen
dc.subjectHumansen
dc.subjectMeta-Analysis as Topicen
dc.subject*Periodicals as Topicen
dc.subjectPublication Biasen
dc.subjectTreatment Outcomeen
dc.titleMagnitude of effects in clinical trials published in high-impact general medical journalsen
heal.typejournalArticle-
heal.type.enJournal articleen
heal.type.elΆρθρο Περιοδικούel
heal.identifier.primary10.1093/ije/dyr095-
heal.identifier.secondaryhttp://www.ncbi.nlm.nih.gov/pubmed/22039194-
heal.identifier.secondaryhttp://ije.oxfordjournals.org/content/40/5/1280.full.pdf-
heal.languageen-
heal.accesscampus-
heal.recordProviderΠανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικήςel
heal.publicationDate2011-
heal.abstractBACKGROUND: Prestigious journals select for publication studies that are considered most important and informative. We aimed to examine whether high-impact general (HIG) medical journals systematically demonstrate more favourable results for experimental interventions compared with the rest of the literature. METHODS: We scrutinized systematic reviews of the Cochrane Database (Issue 4, 2009) and meta-analyses published in four general journals (2008-09). Eligible articles included >/=1 binary outcome meta-analysis(es) pertaining to effectiveness with >/=1 clinical trial(s) published in NEJM, JAMA or Lancet. Effect sizes in trials from NEJM, JAMA or Lancet were compared with those from other trials in the same meta-analyses by deriving summary relative odds ratios (sRORs). Additional analyses examined separately early- and late-published trials in HIG journals and journal-specific effects. RESULTS: A total of 79 meta-analyses including 1043 clinical trials were analysed. Trials in HIG journals had similar effects to trials in other journals, when there was large-scale evidence, but showed more favourable results for experimental interventions when they were small. When HIG trials had less than 40 events, the sROR was 1.64 [95% confidence interval (95% CI): 1.23-2.18). The difference was most prominent when small early trials published in HIG journals were compared with subsequent trials [sROR 2.68 (95% CI: 1.33-5.38)]. Late-published HIG trials showed no consistent inflation of effects. The patterns did not differ beyond chance between NEJM, JAMA or Lancet. CONCLUSIONS: Small trials published in the most prestigious journals show more favourable effects for experimental interventions, and this is most prominent for early-published trials in such journals. No effect inflation is seen for large trials.en
heal.journalNameInt J Epidemiolen
heal.journalTypepeer-reviewed-
heal.fullTextAvailabilityTRUE-
Appears in Collections:Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά) - ΙΑΤ

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