Scope, definition, and consequences of publication bias in clinical trials


  • Framing of hypotheses, definition of suitable and measurable bibliometric features, and statistical indicators
  • Extraction, pre-processing, and standardization of data from information sources
  • Investigation of the influence of registered vs. non-registered studies on the obtained “bibliometric profile” in the cases of systematic reviews 
  • Interpretation of characteristic features and conclusions given the current measures against publication bias

Task 2.1 - Definition of features and indicators for bibliometric analysis and data extraction

  • Review of literature, selection and definition of features for bibliometric respectively text-analytic analyses
  • Selection and definition of indicators, network indicators; and indicators of relational maps, including thematic clusters
  • Compilation of data sets from systematic reviews and additional data sets from clinical trial registries (including but not limited to and other data sources (journal impact factors, etc.)

Task 2.2 - Bibliometric analysis of characteristic features distinctive between registered vs. non-registered studies

  • Coupled bibliometric and downstream statistical analysis on datasets by using stand-alone, network, and relational map analysis 
  • Conduct “co-analyses” (including co-author, co-citation, and co-keyword analysis) to measure and investigate the bibliometric profile of registered vs. non-registered studies across features 
  • Differences between registered vs. non-registered studies, assessment of characteristic features, and comparison between data sets

Task 2.3 - Characteristic bibliometric features of publication bias and conclusions

  • Description of informative features and means for finding differences between registered vs. non-registered studies in terms of bibliometric profile
  • Interpretation of characteristic features in registered vs. non-registered studies in relation to measures to reduce or prevent publication bias and framing of lessons learned