title: Dyadic validity of the Decisional Conflict Scale: common patient/physician measures of patient uncertainty were identified.
abstract: OBJECTIVE
  We aimed to assess the dyadic validity of the Decisional Conflict Scale (DCS) for assessing shared decision making in clinical consultations. We applied dyadic criteria, which consider the patient and physician as an interactive dyad instead of as independent individuals, to identify common patient/physician measures of patient uncertainty.
  
  
  METHODS
  Patients and their physicians, participating in a randomized clustered trial, completed separately an adapted version of the DCS with five subscales. We performed factor analysis on the full DCS and each subscale independently. We defined a measure as dyadic when measurement invariance across patients and physicians was supported.
  
  
  RESULTS
  We analyzed 332 paired responses (physicians with adults or with parents and children) at study entry and 339 at exit. Factor analysis showed that the full DCS is not a valid dyadic measure. However, independent analysis of each subscale showed measurement invariance for values clarity, support, and effective decision (comparative fit index range, 0.93-1; root mean square error of approximation range, 0-0.07; and P-value > 0.05).
  
  
  CONCLUSIONS
  Application of our dyadic validation criterion indicated that the full DCS cannot be considered a dyadic measure. However, three of its subscales, values clarity, support and effective decision, are valid dyadic measures.
authors.affiliation: Research Centre of the Centre Hospitalier Universitaire de Québec, Hôpital St-François d'Assise, 10 rue de l'Espinay, Quebec City, Quebec, G1L 3L5, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Turcotte
authors.affiliation: Research Centre of the Centre Hospitalier Universitaire de Québec, Hôpital St-François d'Assise, 10 rue de l'Espinay, Quebec City, Quebec, G1L 3L5, Canada.
authors.forename: Mireille
authors.initials: M
authors.lastname: Guerrier
authors.affiliation: Research Centre of the Centre Hospitalier Universitaire de Québec, Hôpital St-François d'Assise, 10 rue de l'Espinay, Quebec City, Quebec, G1L 3L5, Canada; Department of Family Medicine and Emergency Medicine, Faculty of Medicine, Université Laval, 1050, avenue Ferdinand-Vandry, Quebec City, Quebec, G1V OA6, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Labrecque
authors.affiliation: Research Centre of the Centre Hospitalier Universitaire de Québec, Hôpital St-François d'Assise, 10 rue de l'Espinay, Quebec City, Quebec, G1L 3L5, Canada.
authors.forename: Hubert
authors.initials: H
authors.lastname: Robitaille
authors.affiliation: Department of Mathematics and Statistics, Faculty of Sciences and Engineering, Université Laval, 1045, avenue de la Médecine, Quebec City, Quebec, G1V OA6, Canada.
authors.forename: Louis-Paul
authors.initials: LP
authors.lastname: Rivest
authors.affiliation: Hess Consulting, 272 Rue du Replat, St-Nicolas, Quebec, G7A 5E4, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Hess
authors.affiliation: Research Centre of the Centre Hospitalier Universitaire de Québec, Hôpital St-François d'Assise, 10 rue de l'Espinay, Quebec City, Quebec, G1L 3L5, Canada; Department of Family Medicine and Emergency Medicine, Faculty of Medicine, Université Laval, 1050, avenue Ferdinand-Vandry, Quebec City, Quebec, G1V OA6, Canada. Electronic address: France.legare@mfa.ulaval.ca.
authors.forename: France
authors.initials: F
authors.lastname: Légaré
mesh_terms: D000328:Adult; D002648:Child; D003220:Conflict, Psychological; D003657:Decision Making; D005163:Factor Analysis, Statistical; D005194:Family Practice; D005260:Female; D006801:Humans; D008297:Male; D010290:Parents / Q000523:psychology; D010817:Physician-Patient Relations; D011594:Psychometrics; D011792:Quebec; D035501:Uncertainty
keywords: Decisional Conflict Scale; Dyadic measures; Patient–physician dyad; Shared decision making; Uncertainty; Validity