title: Dutch Translation and Psychometric Testing of the 9-Item Shared Decision Making Questionnaire (SDM-Q-9) and Shared Decision Making Questionnaire-Physician Version (SDM-Q-Doc) in Primary and Secondary Care.
abstract: OBJECTIVE
  The SDM-Q-9 and SDM-Q-Doc measure patient and physician perception of the extent of shared decision making (SDM) during a physician-patient consultation. So far, no self-report instrument for SDM was available in Dutch, and validation of the scales in other languages has been limited. The aim of this study was to translate both scales into Dutch and assess their psychometric characteristics.
  
  
  METHODS
  Participants were patients and their treating physicians (general practitioners and medical specialists). Patients (N = 182) rated their consultation using the SDM-Q-9, 43 physicians rated their consultations using the SDM-Q-Doc (N = 201). Acceptability, reliability (internal consistency), and the factorial structure of the instruments were determined. For convergent validity the CPSpost was used.
  
  
  RESULTS
  Reliabilities of both scales were high (alpha SDM-Q-9 0.88; SDM-Q-Doc 0.87). The SDM-Q-9 and SDM-Q-Doc total scores correlated as expected with the CPSpost (SDM-Q-9: r = 0.29; SDM-Q-Doc: r = 0.48) and were significantly different between the CPSpost categories, with lowest mean scores when the physician made the decision alone. Principal Component Analyses showed a two-component model for each scale. A confirmatory factor analysis yielded a mediocre, but acceptable, one-factor model, if Item 1 was excluded; for both scales the best indices of fit were obtained for a one-factor solution, if both Items 1 and 9 were excluded.
  
  
  CONCLUSIONS
  The Dutch SDM-Q-9 and SDM-Q-Doc demonstrate good acceptance and reliability; they correlated as expected with the CPSpost and are suitable for use in Dutch primary and specialised care. Although the best model fit was found when excluding Items 1 and 9, we believe these items address important aspects of SDM. Therefore, also based on the coherence with theory and comparability with other studies, we suggest keeping all nine items of the scale. Further research on the SDM-concept in patients and physicians, in different clinical settings and different countries, is necessary to gain a better understanding of the SDM-construct and its measurement.
authors.affiliation: Department of Psychiatry, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Sumayah
authors.initials: S
authors.lastname: Rodenburg-Vandenbussche
authors.affiliation: Department of Medical Decision Making, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Arwen H
authors.initials: AH
authors.lastname: Pieterse
authors.affiliation: Department of Child and Family Studies, Leiden University, Leiden, The Netherlands.
authors.forename: Pieter M
authors.initials: PM
authors.lastname: Kroonenberg
authors.affiliation: Department of Medical Psychology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Scholl
authors.affiliation: Department of Family Medicine, Maastricht University, School CAPHRI, Maastricht, The Netherlands.
authors.forename: Trudy
authors.initials: T
authors.lastname: van der Weijden
authors.affiliation: Department of Ophthalmology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Gre P M
authors.initials: GP
authors.lastname: Luyten
authors.affiliation: Department of Gynaecology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Roy F P M
authors.initials: RF
authors.lastname: Kruitwagen
authors.affiliation: Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Henk
authors.initials: H
authors.lastname: den Ouden
authors.affiliation: Department of Psychiatry, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Ingrid V E
authors.initials: IV
authors.lastname: Carlier
authors.affiliation: Department of Psychiatry, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Irene M
authors.initials: IM
authors.lastname: van Vliet
authors.affiliation: Department of Psychiatry, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Frans G
authors.initials: FG
authors.lastname: Zitman
authors.affiliation: Department of Medical Decision Making, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Stiggelbout
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003657:Decision Making; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D010358:Patient Participation; D010817:Physician-Patient Relations; D011320:Primary Health Care / Q000379:methods*; D011594:Psychometrics; D015203:Reproducibility of Results; D063127:Secondary Health Care / Q000379:methods*; D011795:Surveys and Questionnaires / Q000592:standards*; D014177:Translations; D055815:Young Adult