Article Text

Download PDFPDF
Assessment of publication bias in meta-analyses of cardiovascular diseases

Abstract

Objective: To examine variables related with publication bias assessment in a sample of systematic reviews with meta-analysis on cardiovascular diseases.

Design: Systematic review of meta-analyses.

Setting: Journals indexed in Medline and the Cochrane Library.

Study population: 225 reviews with meta-analysis published between 1990 and 2002.

Data collection: Data from meta-analyses were gathered according to a structured protocol. The outcome was the assessment, not the existence, of publication bias by the original authors.

Results: Publication bias was assessed in 25 (11.1%) reviews, increasing with time: from 3.4% before 1998 to 19.0% in those published in 2002. A stepwise logistic regression model included several variables increasing the assessment of publication bias: number of primary studies (>7 compared with ⩽7, odds ratio (OR)  =  5.40, 95% CI  =  1.36 to 21.44), number of searched databases (⩾4 compared with <3, OR  =  8.58, 95% CI  =  1.73 to 42.62), to be a meta-analysis on observational studies (OR  =  3.60, 95% CI  =  1.04 to 12.49), and year of publication (2002 compared with <2000, OR  =  5.73, 95% CI  =  1.16 to 28.36). In reviews published in the Cochrane Library publication bias was less frequently assessed (OR  =  0.06, 95% CI  =  0.01 to 0.69).

Conclusions: The frequency of assessment of publication bias in meta-analysis is still very low, although it has improved with time. It is more frequent in meta-analyses on observational studies and it is related to other methodological characteristics of reviews.

  • meta-analysis
  • publication bias
  • systematic review

Statistics from Altmetric.com

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Linked Articles