Inadequate use and regulation of interventions against publication bias decreases their effectiveness: a systematic review

J Clin Epidemiol. 2015 Jul;68(7):792-802. doi: 10.1016/j.jclinepi.2015.01.008. Epub 2015 Jan 30.


Objectives: To determine the effectiveness of interventions designed to prevent or reduce publication and related biases.

Study design and setting: We searched multiple databases and performed manual searches using terms related to publication bias and known interventions against publication bias. We dually reviewed citations and assessed risk of bias. We synthesized results by intervention and outcomes measured and graded the quality of the evidence (QoE).

Results: We located 38 eligible studies. The use of prospective trial registries (PTR) has increased since 2005 (seven studies, moderate QoE); however, positive outcome-reporting bias is prevalent (14 studies, low QoE), and information in nonmandatory fields is vague (10 studies, low QoE). Disclosure of financial conflict of interest (CoI) is inadequate (five studies, low QoE). Blinding peer reviewers may reduce geographical bias (two studies, very low QoE), and open-access publishing does not discriminate against authors from low-income countries (two studies, very low QoE).

Conclusion: The use of PTR and CoI disclosures is increasing; however, the adequacy of their use requires improvement. The effect of open-access publication and blinding of peer reviewers on publication bias is unclear, as is the effect of other interventions such as electronic publication and authors' rights to publish their results.

Keywords: Conflict of interest; Geographical bias; Open access; Peer review; Publication bias; Trial registration.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Access to Information / legislation & jurisprudence*
  • Conflict of Interest / legislation & jurisprudence
  • Cost-Benefit Analysis
  • Disclosure / legislation & jurisprudence
  • Peer Review / standards
  • Practice Guidelines as Topic
  • Program Evaluation
  • Prospective Studies
  • Publication Bias / legislation & jurisprudence*
  • Randomized Controlled Trials as Topic / statistics & numerical data
  • Registries / statistics & numerical data