title: An assessment of the measurement equivalence of English and French versions of the Center for Epidemiologic Studies Depression (CES-D) Scale in systemic sclerosis.
abstract: OBJECTIVE
  Center for Epidemiologic Studies Depression (CES-D) Scale scores in English- and French-speaking Canadian systemic sclerosis (SSc) patients are commonly pooled in analyses, but no studies have evaluated the metric equivalence of the English and French CES-D. The study objective was to examine the metric equivalence of the CES-D in English- and French-speaking SSc patients.
  
  
  METHODS
  The CES-D was completed by 1007 English-speaking and 248 French-speaking patients from the Canadian Scleroderma Research Group Registry. Confirmatory factor analysis (CFA) was used to assess the factor structure in both samples. The Multiple-Indicator Multiple-Cause (MIMIC) model was utilized to assess differential item functioning (DIF).
  
  
  RESULTS
  A two-factor model (Positive and Negative affect) showed excellent fit in both samples. Statistically significant, but small-magnitude, DIF was found for 3 of 20 CES-D items, including items 3 (Blues), 10 (Fearful), and 11 (Sleep). Prior to accounting for DIF, French-speaking patients had 0.08 of a standard deviation (SD) lower latent scores for the Positive factor (95% confidence interval [CI]-0.25 to 0.08) and 0.09 SD higher scores (95% CI-0.07 to 0.24) for the Negative factor than English-speaking patients. After DIF correction, there was no change on the Positive factor and a non-significant increase of 0.04 SD on the Negative factor for French-speaking patients (difference = 0.13 SD, 95% CI-0.03 to 0.28).
  
  
  CONCLUSIONS
  The English and French versions of the CES-D, despite minor DIF on several items, are substantively equivalent and can be used in studies that combine data from English- and French-speaking Canadian SSc patients.
authors.affiliation: Department of Educational and Counselling Psychology, McGill University, Montreal, Quebec, Canada; The Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada.
authors.forename: Vanessa C
authors.initials: VC
authors.lastname: Delisle
authors.affiliation: Department of Psychiatry, McGill University, Montreal, Quebec, Canada; The Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada.
authors.forename: Linda
authors.initials: L
authors.lastname: Kwakkenbos
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada; The Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada.
authors.forename: Marie
authors.initials: M
authors.lastname: Hudson
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada; The Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada.
authors.forename: Murray
authors.initials: M
authors.lastname: Baron
authors.affiliation: Department of Educational and Counselling Psychology, McGill University, Montreal, Quebec, Canada; Department of Psychiatry, McGill University, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada; Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada; Department of Psychology, McGill University, Montreal, Quebec, Canada; School of Nursing, McGill University, Montreal, Quebec, Canada; The Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada.
authors.forename: Brett D
authors.initials: BD
authors.lastname: Thombs
mesh_terms: D003863:Depression / Q000523:psychology*; D003866:Depressive Disorder / Q000523:psychology*; D016021:Epidemiologic Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012595:Scleroderma, Systemic / Q000150:complications* / Q000523:psychology*; D044465:White People / Q000523:psychology*