Comparison of Self-Report and Structured Clinical Interview Scores for the Assessment of the Level of Personality Functioning Scale.

This study addresses the need for an examination of the criterion validity of a highly popular self-report instrument which is used to gain a quick first impression of personality dysfunction: the Level of Personality Functioning Scale-Brief Form 2.0 (LPFS-BF 2.0). To this end, the relationship between LPFS-BF 2.0 scores and SCID-5-AMPD-I scores rated by trained clinicians was investigated in a clinical Norwegian sample (N = 155). Moreover, we investigated the relationship between the Norwegian version of the LPFS-BF 2.0 and other self-report instruments (the WSAS, GAD-7, and PHQ-9). Correlations, a linear regression model, as well as sensitivity and specificity for cut-off values proposed in the literature, were estimated. The results of the linear regression analysis with SCID-5-AMPD-I scores as the dependent variable, showed a strong and significant relationship between LPFS-BF 2.0 scores and SCID-5-AMPD-I scores, also when controlling for other variables. The LPFS-BF 2.0 showed moderate to high correlations with all other instruments. The sensitivity values for cut-off scores suggested in the literature for the LPFS-BF 2.0 were too low. In sum, we found support for the concurrent and criterion validity of the LPFS-BF 2.0. Additionally, we tentatively suggest that the cut-off values currently in use may need to be lowered.