title: Methodological index for non-randomized studies (minors): development and validation of a new instrument.
abstract: BACKGROUND
  Because of specific methodological difficulties in conducting randomized trials, surgical research remains dependent predominantly on observational or non-randomized studies. Few validated instruments are available to determine the methodological quality of such studies either from the reader's perspective or for the purpose of meta-analysis. The aim of the present study was to develop and validate such an instrument.
  
  
  METHODS
  After an initial conceptualization phase of a methodological index for non-randomized studies (MINORS), a list of 12 potential items was sent to 100 experts from different surgical specialties for evaluation and was also assessed by 10 clinical methodologists. Subsequent testing involved the assessment of inter-reviewer agreement, test-retest reliability at 2 months, internal consistency reliability and external validity.
  
  
  RESULTS
  The final version of MINORS contained 12 items, the first eight being specifically for non-comparative studies. Reliability was established on the basis of good inter-reviewer agreement, high test-retest reliability by the kappa-coefficient and good internal consistency by a high Cronbach's alpha-coefficient. External validity was established in terms of the ability of MINORS to identify excellent trials.
  
  
  CONCLUSIONS
  MINORS is a valid instrument designed to assess the methodological quality of non-randomized surgical studies, whether comparative or non-comparative. The next step will be to determine its external validity when used in a large number of studies and to compare it with other existing instruments.
authors.affiliation: Department of General and Digestive Surgery, Hôtel-Dieu, Clermont-Ferrand, France. kslim@chu-clermontferrand.fr
authors.forename: Karem
authors.initials: K
authors.lastname: Slim
authors.forename: Emile
authors.initials: E
authors.lastname: Nini
authors.forename: Damien
authors.initials: D
authors.lastname: Forestier
authors.forename: Fabrice
authors.initials: F
authors.lastname: Kwiatkowski
authors.forename: Yves
authors.initials: Y
authors.lastname: Panis
authors.forename: Jacques
authors.initials: J
authors.lastname: Chipponi
mesh_terms: D002986:Clinical Trials as Topic / Q000592:standards*; D006801:Humans; D017712:Peer Review, Research / Q000379:methods*; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards*