Age-neutrality of the trait facets proposed for personality disorders in DSM-5: A DIFAS analysis of the PID-5.

An age-neutral measurement system is one of the basic conditions for an accurate personality assessment across the lifespan, both longitudinally and cross-sectionally. In this study the age-neutrality of the Personality Inventory for DSM-5 (PID-5; Krueger et al., 2012) was investigated. Potential Differential Item Functioning (DIF) was examined for the 25 trait facets in older versus younger adults. Overall, 33 items displayed large DIF, according to the adjusted Bonferroni corrected cutoffs (Mantel Chi-square, Liu-Agresti Cumulative Common Log-Odds Ratio [L-A LOR], and Cox's Noncentrality Parameter Estimator [Cox's B]). In a next step, the implications of the item level DIF across age groups was investigated on scale (i.e., facet) level. These Differential Test Functioning (DTF) analyses revealed large DTF for four of the 25 PID-5 facets (i.e., Withdrawal, Attention Seeking, Rigid Perfectionism and Unusual Beliefs). Current initial results show that most PID-5 traits are measured equally well across age, however, further research is needed to further refine this instrument and make it entirely age-neutral.