Normative data for the LPFS-BF 2.0 derived from the Danish general population and relationship with psychosocial impairment

The Level of Personality Functioning Scale-Brief Form 2.0 is a frequently used self-report inventory that may be used to screen for self- and interpersonal dysfunction according to the DSM-5 Alternative Model for Personality Disorders (AMPD) and the ICD-11 Classification of Personality Disorders. Nevertheless, reliable norms and cut-off scores to aid interpretation and clinical decision making are still lacking. The LPFS-BF and relevant impairment measures were administered to a sociodemographically stratisfied sample of 2,002 adults from the general Danish population of whom 713 individuals eventually delivered data for inclusion in the present study. The unidimensionality of the LPFS-BF scores was established using Confirmatory Factor Analysis (CFA). Item-Response Theory (IRT) analysis indicated satisfactory item functioning for all 12 items and suggested normative observed score thresholds at different latent severity levels. Meaningful associations were found between the LPFS-BF norm-based cut-off scores, quality of life, and social and occupational functioning. This study presented the first normative data for LPFS-BF, which specifically applies to Denmark but likely also other socioeconomically comparable Nordic and Western societies. These results allow for interpretation of LPFS-BF scores and clinical decision-making. Future research should corroborate these findings and compare them to scores obtained in other general population samples.