Table 1

Rating of the six procedures examined

Search of unpublished trials and/or test for publication biasUnpublished trials not searched, publication bias not testedUnpublished trials searched OR publication bias testedUnpublished trials searched AND publication bias tested or statistically corrected
Contact with study authorsStudy authors not contactedStudy authors contacted for methodology or unspecified reasonsStudy authors contacted to unearth unreported endpoints
Duplicate publicationsDuplicate publications not searched or not mentionedDuplicate publications searchedDuplicate publications referenced in the published report*
Sponsors of the studiesInformation on study sponsors not reportedInformation on study sponsors reportedImpact of study sponsor(s) on the conclusions of the review analysed
Study authors’ conflicts of interestStudy authors’ conflicts of interest not reportedStudy authors’ conflicts of interest reportedImpact of study authors’ conflicts of interest on the conclusions of the review analysed
Ethical approvalEthical approval of included studies not reportedEthical approval of included studies reportedLack of ethical approval of included studies reported and referenced†
  • Percentages may not add-up to 100% because of rounding errors.

  • *Also includes reports that explicitly mention that no duplicates were identified.

  • †Also includes reports that explicitly mention that none of the included studies lacked ethical approval.