title: The use of systematic reviews when designing studies.
abstract: BACKGROUND
  The importance of systematic reviews in identifying gaps in the evidence base and providing a quantitative basis for informing new research initiatives is widely acknowledged, but little is known about what actually happens in practice. Our objective was to assess the use made of results of reviews in the designing of new studies.
  
  
  METHODS
  Of all Cochrane reviews published in 1996, those updated in 2002 or 2003 were identified. Authors of trials added in the updates were contacted and asked if use had been made of the 1996 Cochrane or other reviews in designing their study.
  
  
  RESULTS
  Of 32 authors of studies newly included in 33 Cochrane reviews which met our inclusion criteria, 24 (75%) responded. Eleven (46%) respondents were aware of the relevant Cochrane review at the time they designed their study. In eight (33%) cases the design of the new study had been influenced by a review; in two (8%) this was the relevant Cochrane review.
  
  
  CONCLUSIONS
  Cautious interpretation of these results is necessary, but it is apparent that the proportion of study investigators using Cochrane or other systematic reviews in designing their new studies was very limited. Inclusion of encouragement in publication or application guidelines to consider and cite review results is desirable.
authors.affiliation: Centre for Biostatistics and Genetic Epidemiology, Department of Health Sciences, University of Leicester, Leicester, UK. njc21@le.ac.uk
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Cooper
authors.forename: David R
authors.initials: DR
authors.lastname: Jones
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Sutton
mesh_terms: D002986:Clinical Trials as Topic; D019992:Databases as Topic; D019317:Evidence-Based Medicine; D006801:Humans; D015201:Meta-Analysis as Topic; D012107:Research Design; D012196:Review Literature as Topic