Further Reliability, Convergent and Discriminant Validity of Overall Defensive Functioning.

The reliability, convergent and discriminant validity of the Defensive Functioning Scale (DFS) and the overall defensive functioning score (ODF) has been previously examined. This study aims to address gaps in the literature as well as to replicate and extend the initial positive clinical validity data emerging on the DFS ( Blais et al., 1996; Hoglend and Perry, 1998; Lingiardi et al., 1999; Perry 2001; Perry and Hoglend, 1998; Perry et al., 1998). Fifty-three outpatient clients were rated by clinicians trained on the DFS. The relationship between the ODF with both clinician-rated and self-report measures of psychopathology was examined. The mean interrater reliability for the DFS levels rated in this study was found to be moderate to high, and reliability for the ODF score was found to be excellent. Coefficient alpha of individual defense levels as well as across the entire DFS indicated high levels of internal consistency. Factor analysis revealed that the ODF represents a construct different from various aspects of patient self-report and clinician ratings of psychopathology. These results provide further support for the clinical application and relevance of the DFS system.