title: The COSMIN checklist for assessing the methodological quality of studies on measurement properties of health status measurement instruments: an international Delphi study.
abstract: BACKGROUND
  Aim of the COSMIN study (COnsensus-based Standards for the selection of health status Measurement INstruments) was to develop a consensus-based checklist to evaluate the methodological quality of studies on measurement properties. We present the COSMIN checklist and the agreement of the panel on the items of the checklist.
  
  
  METHODS
  A four-round Delphi study was performed with international experts (psychologists, epidemiologists, statisticians and clinicians). Of the 91 invited experts, 57 agreed to participate (63%). Panel members were asked to rate their (dis)agreement with each proposal on a five-point scale. Consensus was considered to be reached when at least 67% of the panel members indicated 'agree' or 'strongly agree'.
  
  
  RESULTS
  Consensus was reached on the inclusion of the following measurement properties: internal consistency, reliability, measurement error, content validity (including face validity), construct validity (including structural validity, hypotheses testing and cross-cultural validity), criterion validity, responsiveness, and interpretability. The latter was not considered a measurement property. The panel also reached consensus on how these properties should be assessed.
  
  
  CONCLUSIONS
  The resulting COSMIN checklist could be useful when selecting a measurement instrument, peer-reviewing a manuscript, designing or reporting a study on measurement properties, or for educational purposes.
authors.affiliation: Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands. w.mokkink@vumc.nl
authors.forename: Lidwine B
authors.initials: LB
authors.lastname: Mokkink
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Terwee
authors.forename: Donald L
authors.initials: DL
authors.lastname: Patrick
authors.forename: Jordi
authors.initials: J
authors.lastname: Alonso
authors.forename: Paul W
authors.initials: PW
authors.lastname: Stratford
authors.forename: Dirk L
authors.initials: DL
authors.lastname: Knol
authors.forename: Lex M
authors.initials: LM
authors.lastname: Bouter
authors.forename: Henrica C W
authors.initials: HC
authors.lastname: de Vet
mesh_terms: D003697:Delphi Technique; D006305:Health Status Indicators; D006801:Humans; D038622:Internationality; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012107:Research Design; D018434:Sickness Impact Profile; D013223:Statistics as Topic; D011795:Surveys and Questionnaires