Comparative Content Analysis of Self-Report Scales for Level of Personality Functioning

Content validity analyses of eight self-report instruments for assessing severity of personality disorder (PD), also known as Level of Personality Functioning (LPF), were conducted using the conceptual scheme of the Alternative Model for Personality Disorders (AMPD; APA, 2013). The item contents of these eight inventories were characterized for the LPF constructs of Identity (ID), Self-Direction (SD), Empathy (EM), and Intimacy (IN) along with the pathological personality trait domains of Negative Affectivity, Detachment, Antagonism, Disinhibition, and Psychoticism. Severity of pathology (SV) reflected in item content was also rated. Raters demonstrated robust agreement for AMPD and SV constructs across instruments. Similarity between instrument AMPD construct profiles was quantified by intraclass correlations (ICC). Results showed the instruments were generally similar in AMPD-construct coverage, but some important differences emerged. The subscales of the instruments also were characterized for the degree to which they reflect the four LPF (ID, SD, EM, IN) domain constructs. Collectively, these content validity comparisons clarify the equivalence of instruments for AMPD constructs and the relative proportions of construct coverage within instrument subscales. These results can inform future research with LPF self-report instruments and guide clinicians in selecting an LPF-related instrument for use in practice.