title: Up-to-dateness of reviews is often neglected in overviews: a systematic review.
abstract: OBJECTIVE
  As systematic reviews may run out of date, it might be necessary to update them. Out-of-date reviews may jeopardize the comparability when used in the context of overviews (review of reviews).
  
  
  METHODS
  Seven electronic databases were searched for overviews up to November 2012. We first aimed to analyze whether the authors of overviews additionally searched for primary studies or alternatively explained why they did not. Second, we sought to analyze the actual publication lag (publication date of the overview - publication date of the review) in overviews and to develop recommendations for authors of overviews.
  
  
  RESULTS
  We included 147 overviews. The mean publication lag in overviews was more than 5 years. A median of 36% of the reviews were published more than 6 years ago. Only one in four reviews considered up-to-dateness. The methods for updating reviews were heterogeneous. We found no overview that systematically investigated whether an update was necessary.
  
  
  CONCLUSIONS
  The issue of up-to-dateness when conducting overviews seems to be neglected by most authors of overviews. Authors should assess the quality of evidence, based on their included reviews first.
authors.affiliation: Institute for Research in Operative Medicine, Faculty of Health, School of Medicine, Witten/Herdecke University, Ostmerheimer Str. 200, Building 38, D-51109 Cologne, Germany. Electronic address: dawid.pieper@uni-wh.de.
authors.forename: Dawid
authors.initials: D
authors.lastname: Pieper
authors.affiliation: Institute for Research in Operative Medicine, Faculty of Health, School of Medicine, Witten/Herdecke University, Ostmerheimer Str. 200, Building 38, D-51109 Cologne, Germany.
authors.forename: Sunya-Lee
authors.initials: SL
authors.lastname: Antoine
authors.affiliation: Institute for Research in Operative Medicine, Faculty of Health, School of Medicine, Witten/Herdecke University, Ostmerheimer Str. 200, Building 38, D-51109 Cologne, Germany.
authors.forename: Edmund A M
authors.initials: EA
authors.lastname: Neugebauer
authors.affiliation: Institute for Research in Operative Medicine, Faculty of Health, School of Medicine, Witten/Herdecke University, Ostmerheimer Str. 200, Building 38, D-51109 Cologne, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Eikermann
mesh_terms: D035843:Biomedical Research; D006801:Humans; D011643:Publishing / Q000592:standards*; D012196:Review Literature as Topic
keywords: Evidence-based medicine; Information science; Meta-analysis; Methods; Research design; Systematic review