title: Concordance between personality disorder assessment methods.
abstract: BACKGROUND
  Studies have criticized the low level of agreement between the various methods of personality disorder (PD) assessment. This is an important issue for research and clinical purposes.
  
  
  METHODS
  Seven hundred and forty-two participants in the Hopkins Epidemiology of Personality Disorders Study (HEPS) were assessed on two occasions using the Personality Disorder Schedule (PDS) and the International Personality Disorder Examination (IPDE). The concordance between the two diagnostic methods for all DSM-IV PDs was assessed using standard methods and also two item response analytic approaches designed to take account of measurement error: a latent trait-based approach and a generalized estimating equations (GEE)-based approach, with post-hoc adjustment.
  
  
  RESULTS
  Raw criteria counts, using the intraclass correlation coefficient (ICC), κ and odds ratio (OR), showed poor concordance. The more refined statistical methods showed a moderate to moderately high level of concordance between the methods for most PDs studied. Overall, the PDS produced lower prevalences of traits but higher precision of measurement than the IPDE. Specific criteria within each PD showed varying endorsement thresholds and precision for ascertaining the disorder.
  
  
  CONCLUSIONS
  Concordance in the raw measurement of the individual PD criteria between the two clinical methods is lacking. However, based on two statistical methods that adjust for differential endorsement thresholds and measurement error in the assessments, we deduce that the PD constructs themselves can be measured with a moderate degree of confidence regardless of the clinical approach used. This may suggest that the individual criteria for each PD are, in and of themselves, less specific for diagnosis, but as a group the criteria for each PD usefully identify specific PD constructs.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. gnestadt@jhmi.edu
authors.forename: G
authors.initials: G
authors.lastname: Nestadt
authors.forename: C
authors.initials: C
authors.lastname: Di
authors.forename: J F
authors.initials: JF
authors.lastname: Samuels
authors.forename: Y-J
authors.initials: YJ
authors.lastname: Cheng
authors.forename: O J
authors.initials: OJ
authors.lastname: Bienvenu
authors.forename: I M
authors.initials: IM
authors.lastname: Reti
authors.forename: P
authors.initials: P
authors.lastname: Costa
authors.forename: W W
authors.initials: WW
authors.lastname: Eaton
authors.forename: K
authors.initials: K
authors.lastname: Bandeen-Roche
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007406:Interview, Psychological / Q000592:standards*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D010552:Personality Assessment / Q000592:standards; D010554:Personality Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D011594:Psychometrics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index