Psychometric evaluation of the Level of Personality Functioning Scale - Brief Form 2.0 in adults with chronic pain

Chronic pain and personality disorders frequently co-occur. This co-occurrence may pose challenges in pain management and should be addressed by clinicians to optimize outcomes. The Level of Personality Functioning Scale - Brief Form 2.0 (LPFS-BF) is a time-efficient screening tool for impairments in personality functioning based on the Alternative DSM-5 Model for Personality Disorders.

This cross-sectional study evaluates the psychometric properties of the LPFS-BF in a sample of adults with chronic pain. Data was retrieved from the Oslo University Hospital Pain Registry and includes 892 participants referred to outpatient pain management. The psychometric properties of the LPFS-BF were investigated in terms of factor structure, scale reliability, and concurrent validity with anxiety and depression, health-related quality of life, and past week usual pain intensity.

Mean age was 49 years and 64 % were female. A bifactor structure showed best model fit: Comparative fit index=0.995, Tucker-Lewis index=0.993, root mean square error of approximation=0.023, standardized root mean square residual=0.030. Scale reliability was good for the general factor (ω _t =0.89, ω _h =0.79), poor for the self domain (ω _t =0.25, ω _h =0.05), and questionable for the interpersonal domain (ω _t =0.68, ω _h =0.40). Explained common variance for the general factor was 68 % which supported essential unidimensionality. The magnitudes of the associations between the LPFS-BF and the investigated variables were comparable to previous research, thus supporting its concurrent validity.

The results suggest that the LPFS-BF is best viewed as a unidimensional scale in the current sample and support the LPFS-BF as a valid and reliable screening tool for impairments in personality functioning among individuals with chronic pain.