Development and psychometric evaluation of the Personality Disorder Severity ICD‐11 (PDS‐ICD‐11) Clinician‐Rating Form

Abstract

AbstractNo clinician‐rating tool has formally been developed to assess the ICD‐11 model of personality disorder (PD) severity. We therefore developed and evaluated the 14‐item personality disorder Severity ICD‐11 (PDS‐ICD‐11) Clinician‐Rating Form. A combined sample of 195 patients was rated by mental health professionals or clinical research assistants in New Zealand using the PDS‐ICD‐11 Clinician‐Rating Form. Responses were subjected to item‐response theory analysis and confirmatory factor analysis. In a subsample, we examined interrater reliability and convergence with self‐ and informant‐reported measures of personality impairment, dysfunction in various psychopathology domains, and traditional PD symptoms. Item‐response theory and confirmatory factor analyses supported the item functioning and unidimensionality, respectively, of the PDS‐ICD‐11 Clinician‐Rating Form. The interrater reliability was very promising (intraclass correlation coefficient = 0.94, p < 0.001). PDS‐ICD‐11 Clinician‐Rating Form scores were associated with established measures of personality dysfunction at large effect sizes. This initial development study suggests that the PDS‐ICD‐11 Clinician‐Rating Form constitutes a psychometrically sound instrument that provides a clinically based impression of the severity of personality dysfunction according to the official ICD‐11 description. More research is needed to corroborate its validity and utility, and a structured interview is warranted for diagnostic purposes. The final PDS‐ICD‐11 Clinician‐Rating Form is included as online supporting information.