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https://olympias.lib.uoi.gr/jspui/handle/123456789/18108Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.author | Pereira, T. V. | en |
| dc.contributor.author | Ioannidis, J. P. | en |
| dc.date.accessioned | 2015-11-24T18:50:35Z | - |
| dc.date.available | 2015-11-24T18:50:35Z | - |
| dc.identifier.issn | 1878-5921 | - |
| dc.identifier.uri | https://olympias.lib.uoi.gr/jspui/handle/123456789/18108 | - |
| dc.rights | Default Licence | - |
| dc.subject | Bias (Epidemiology) | en |
| dc.subject | Clinical Trials as Topic/*standards | en |
| dc.subject | Health Services Research/methods/standards | en |
| dc.subject | Humans | en |
| dc.subject | *Meta-Analysis as Topic | en |
| dc.title | Statistically significant meta-analyses of clinical trials have modest credibility and inflated effects | en |
| heal.type | journalArticle | - |
| heal.type.en | Journal article | en |
| heal.type.el | Άρθρο Περιοδικού | el |
| heal.identifier.primary | 10.1016/j.jclinepi.2010.12.012 | - |
| heal.identifier.secondary | http://www.ncbi.nlm.nih.gov/pubmed/21454050 | - |
| heal.identifier.secondary | http://ac.els-cdn.com/S0895435611000096/1-s2.0-S0895435611000096-main.pdf?_tid=850ed0e83aa218ff99419c07f5ba70ba&acdnat=1333363381_46c982d4ce43cdc44491c0772f59f1d7 | - |
| heal.language | en | - |
| heal.access | campus | - |
| heal.recordProvider | Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικής | el |
| heal.publicationDate | 2011 | - |
| heal.abstract | OBJECTIVE: To assess whether nominally statistically significant effects in meta-analyses of clinical trials are true and whether their magnitude is inflated. STUDY DESIGN AND SETTING: Data from the Cochrane Database of Systematic Reviews 2005 (issue 4) and 2010 (issue 1) were used. We considered meta-analyses with binary outcomes and four or more trials in 2005 with P<0.05 for the random-effects odds ratio (OR). We examined whether any of these meta-analyses had updated counterparts in 2010. We estimated the credibility (true-positive probability) under different prior assumptions and inflation in OR estimates in 2005. RESULTS: Four hundred sixty-one meta-analyses in 2005 were eligible, and 80 had additional trials included by 2010. The effect sizes (ORs) were smaller in the updating data (2005-2010) than in the respective meta-analyses in 2005 (median 0.85-fold, interquartile range [IQR]: 0.66-1.06), even more prominently for meta-analyses with less than 300 events in 2005 (median 0.67-fold, IQR: 0.54-0.96). Mean credibility of the 461 meta-analyses in 2005 was 63-84% depending on the assumptions made. Credibility estimates changed >20% in 19-31 (24-39%) of the 80 updated meta-analyses. CONCLUSIONS: Most meta-analyses with nominally significant results pertain to truly nonnull effects, but exceptions are not uncommon. The magnitude of observed effects, especially in meta-analyses with limited evidence, is often inflated. | en |
| heal.journalName | J Clin Epidemiol | en |
| heal.journalType | peer-reviewed | - |
| heal.fullTextAvailability | TRUE | - |
| Appears in Collections: | Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά) - ΙΑΤ | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| Pereira-2011-Statistically signif.pdf | 287.48 kB | Adobe PDF | View/Open Request a copy |
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