Poor reporting of search strategy and conflict of interest in over 250 narrative and systematic reviews of two biologic agents in arthritis: a systematic review

J Clin Epidemiol. 2009 Feb;62(2):128-37. doi: 10.1016/j.jclinepi.2008.08.003. Epub 2008 Nov 14.


Objective: To evaluate the quality of reviews about etanercept (ETN) and infliximab (IFX), two biologic treatments for rheumatoid arthritis (RA).

Study design: A comprehensive, systematic review, including searches of MEDLINE, EMBASE, and other electronic databases and hand-searches for published and unpublished literature. Two raters independently examined each article and identified systematic reviews as those including either a description of: (1) sources for identification and data retrieval; or (2) search strategy. They applied the quality of reporting of meta-analyses (QUOROM) instrument to systematic reviews.

Results: Of 3,620 total citations, 281 were identified as reviews. Of these, 26 (9%) qualified as systematic rather than narrative. Overall, few reviews described selection of sources, critical appraisal, or quantitative summary or synthesis. Systematic reviews most often failed to explain validity assessment. Several articles did not disclose authors' participation in industry-funded clinical trials. Most reviews published in high impact factor and rheumatology journals did not meet many quality standards. Significant associations existed between review type (narrative vs. systematic) and reported funding (P=0.05), conflicts of interest (P=0.005), and country of publication (P<0.0001).

Conclusion: More than 90% of the published reviews were narrative and did not report methods and conflicts of interest in sufficient detail, raising concerns about selection and reporting bias.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review
  • Systematic Review

MeSH terms

  • Antibodies, Monoclonal / therapeutic use
  • Antirheumatic Agents / therapeutic use
  • Arthritis, Rheumatoid / drug therapy
  • Conflict of Interest
  • Etanercept
  • Humans
  • Immunoglobulin G / therapeutic use
  • Infliximab
  • Journal Impact Factor
  • Meta-Analysis as Topic
  • Peer Review
  • Publishing / standards*
  • Receptors, Tumor Necrosis Factor / therapeutic use
  • Review Literature as Topic*


  • Antibodies, Monoclonal
  • Antirheumatic Agents
  • Immunoglobulin G
  • Receptors, Tumor Necrosis Factor
  • Infliximab
  • Etanercept