title: Choosing Important Health Outcomes for Comparative Effectiveness Research: An Updated Review and User Survey.
abstract: BACKGROUND
  A COS represents an agreed minimum set of outcomes that should be measured and reported in all trials of a specific condition. The COMET (Core Outcome Measures in Effectiveness Trials) initiative aims to collate and stimulate the development and application of COS, by including data on relevant studies within a publically available internet-based resource. In recent years, there has been an interest in increasing the development of COS. Therefore, this study aimed to provide an update of a previous review, and examine the quality of development of COS. A further aim was to understand the reasons why individuals are searching the COMET database.
  
  
  METHODS
  A multi-faceted search strategy was followed, in order to identify studies that sought to determine which outcomes/domains to measure in clinical trials of a specific condition. Additionally, a pop up survey was added to the COMET website, to ascertain why people were searching the COMET database.
  
  
  RESULTS
  Thirty-two reports relating to 29 studies were eligible for inclusion in the review. There has been an improvement in the description of the scope of a COS and an increase in the proportion of studies using literature/systematic reviews and the Delphi technique. Clinical experts continue to be the most common group involved in developing COS, however patient and public involvement has increased. The pop-up survey revealed the most common reasons for visiting the COMET website to be thinking about developing a COS and planning a clinical trial.
  
  
  CONCLUSIONS
  This update demonstrates that recent studies appear to have adopted a more structured approach towards COS development and public representation has increased. However, there remains a need for developers to adequately describe details about the scope of COS, and for greater public engagement. The COMET database appears to be a useful resource for both COS developers and users of COS.
authors.affiliation: Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Gorst
authors.affiliation: Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Gargon
authors.affiliation: Northern Ireland Network for Trials Methodology Research, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: Mike
authors.initials: M
authors.lastname: Clarke
authors.affiliation: School of Social and Community Medicine, University of Bristol, and Division of Surgery, Head & Neck, University Hospitals NHS Foundation Trust, Bristol, United Kingdom.
authors.forename: Jane M
authors.initials: JM
authors.lastname: Blazeby
authors.affiliation: Centre for Statistics in Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Altman
authors.affiliation: Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Paula R
authors.initials: PR
authors.lastname: Williamson
mesh_terms: D001364:Awareness; D002755:Choice Behavior; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data; D057186:Comparative Effectiveness Research / Q000379:methods*; D016208:Databases, Factual / Q000706:statistics & numerical data*; D006801:Humans; D019359:Knowledge; D017063:Outcome Assessment, Health Care; D011643:Publishing / Q000592:standards / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires