Item Response Theory Analyses, Factor Structure, and External Correlates of the Italian Translation of the Personality Inventory for DSM

To assess the psychometric properties of the Italian translation of the 100-item short form of the Personality Inventory for DSM-5 (PID-5-SF), 2,143 community-dwelling adults (59.6% female), and 706 adult clinical participants (52.4% female) were administered the Italian translation of the PID-5. Clinical participants were also administered the Structured Clinical Interview for DSM-IV (SCID-II), and the Personality Diagnostic Questionnaire-4+ (PDQ-4+). Item response theory analysis showed that all proposed PID-5-SF items showed adequate item discrimination parameters in both community-dwelling adults and clinical adults. All PID-5-SF trait scales showed satisfactory internal consistency estimates. PID-5-SF five-factor structure closely matched the factor structure of the PID-5 in both community-dwelling participants and clinical participants and was invariant across the two samples that participated in this study. Moreover, the factor structure of the PID-5-SF closely replicated the factor of the PID-5-SF that was originally reported in Maples et al.’s study. In our clinical sample, dominance analysis results showed that PID-5-SF scales explained a nonnegligible and significant amount of variance in both SCID-II and PDQ-4+ ratings of selected DSM-5 Section II personality disorder, and the use of the PID-5-SF did not result in a substantial loss of information as compared with the original PID-5