Measurement invariance on two self-report instruments for men and women with borderline personality disorder.

Background: In clinical practice and research, self-report instruments are frequently used for assessing the severity of borderline personality disorder (BPD) symptomatology experienced by men and women. Men with BPD are often underrepresented in samples used to evaluate self-report questionnaires. Measurement invariance (MI) is used to examine whether self-report questionnaires determine the same latent construct across groups or varying conditions (e.g., measurement occasions).

Methods: The present study investigated measurement invariance for two self-report measures of BPD features: the Borderline Symptom List (BSL-23) and the Impulsivity and Emotion Dysregulation Scale (IES-27). An inpatient sample of N = 3507 individuals (n = 560 males) was used to test for measurement variance between males and females, and over time from pre- to post-treatment.

Results: Confirmatory factor analysis results supported a unidimensional structure for the BSL-23 and a three-factor model for the IES-27. Both instruments were found to be measurement invariant with regard to sex and time.

Conclusions: The results suggest that the BSL-23 and IES-27 can be used to assess BPD symptoms in men and women, as well as to assess treatment effects at admission and at the end of treatment.