Unpublished data can be of value in systematic reviews of adverse effects: methodological overview. methodological overview

Su Golder, Yoon K Loke, Martin Bland

Research output: Contribution to journalArticlepeer-review

Abstract

Objective: To assess the impact of including unpublished data on adverse effects in systematic reviews.

Study Design and Setting: We carried out a systematic review of methodological evaluations that compared the quantitative reporting of adverse effects data between published and unpublished sources, in particular, the frequency, rate, or risk of reported adverse effects. Included studies were sought from 10 databases as well as by checking references, handsearching, searching citations, and contacting experts.

Results: We identified 6,218 potential articles yielding 10 relevant methodological evaluations. One evaluation found that adverse effects were reported more often in unpublished trials. For anecdotal case reports, two evaluations found a higher frequency of unpublished cases, whereas one study identified a greater number of published cases. Another evaluation indicated that differences in frequency of published and unpublished case reports were topic dependent.

A comparison of relative risk estimates from five studies suggested no major systematic variation in risk estimates from published and unpublished studies.

Conclusion: Inclusion of unpublished studies can provide additional adverse effects information and more precise risk estimates. However, there is insufficient evidence to indicate whether inclusion of unpublished studies has a major influence on the pooled risk estimates in meta-analyses of adverse effects. (C) 2010 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)1071-1081
Number of pages11
JournalJournal of Clinical Epidemiology
Volume63
Issue number10
DOIs
Publication statusPublished - Oct 2010

Bibliographical note

Copyright (c) 2010 Elsevier Inc. All rights reserved.

Keywords

  • Systematic review
  • Literature review
  • Adverse effects
  • Publication bias
  • Meta-analysis
  • Unpublished data
  • SEROTONIN REUPTAKE INHIBITORS
  • OUTCOME REPORTING BIAS
  • RANDOMIZED-TRIALS
  • CLINICAL-TRIALS
  • METAANALYSIS
  • EVENTS
  • SAFETY
  • PUBLICATION
  • DEPRESSION
  • RISK

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