title: Cross-validation of the Depression, Anxiety, and Positive Outlook Scale (DAPOS) for clinical use.
abstract: OBJECTIVE
  The main objective of this study was to investigate different psychometric properties of the Swedish version of the Depression, Anxiety, and Positive Outlook Scale (DAPOS) in patients with chronic musculoskeletal pain in an orthopedic setting.
  
  
  METHODS
  A total of 449 participants took part in the study, including 288 patients with chronic musculoskeletal pain and 161 participants in a reference group. Internal consistency, convergent validity, and measurement invariance of the constructs of DAPOS were investigated across sex and diagnostic groups. The Beck Depression Inventory and the Spielberger Anxiety Inventory were used for measures of convergent validity. Multigroup confirmatory factor analysis was performed to test measurement invariance of the theoretical constructs of DAPOS.
  
  
  RESULTS
  Internal consistency was good for all 3 constructs, and correlations concerned with convergent validity were found to be acceptable to good. With regard to cross-validation, the 3 constructs of DAPOS were strictly measurement invariant with respect to sex. Across diagnostic groups, the constructs of anxiety and positive outlook were almost strictly measurement invariant, although there were some restrictions of measurement invariance for the construct of depression.
  
  
  CONCLUSIONS
  To be able to rely on an instrument with as few items as DAPOS, the cross-validation of its constructs for sex and diagnostic groups is a valuable information, particularly when investigated in patients with musculoskeletal pain. Based on these results, we recommend that DAPOS could replace longer and more time-consuming screening tests in clinical settings.
authors.affiliation: Department of Occupational Orthopedics, Sahlgrenska University Hospital, Per Dubbsgatan 14, Gothenburg, Sweden. patricia.olaya@orthop.gu.se
authors.forename: Patricia
authors.initials: P
authors.lastname: Olaya-Contreras
authors.forename: Jorma
authors.initials: J
authors.lastname: Styf
authors.forename: Mari
authors.initials: M
authors.lastname: Lundberg
authors.forename: Bengt
authors.initials: B
authors.lastname: Jansson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology*; D016009:Chi-Square Distribution; D002908:Chronic Disease; D003863:Depression / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000150:complications; D010146:Pain / Q000150:complications; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000379:methods*; D015203:Reproducibility of Results; D012737:Sex Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult