Self-rated impulsivity in healthy individuals, substance use disorder and ADHD: psychometric properties of the Swedish Barratt impulsiveness scale.

ABSTRACT

BACKGROUND: Impulsivity is associated with several psychiatric disorders, including substance use disorders (SUD) and attention deficit hyperactivity disorder (ADHD). A widely used questionnaire to assess impulsivity is the Barratt Impulsiveness Scale (BIS), and the aim of the current study was to evaluate the psychometric properties of the Swedish version of the BIS (swe-BIS). METHODS: The original BIS was translated to Swedish and back-translated by an authorized translator. The swe-BIS was administered to healthy controls (n = 113), patients with alcohol use disorder (n = 97), amphetamine use disorder (n = 37) and attention deficit hyperactive disorder (ADHD; n = 26). A subset of subjects (n = 62) completed the swe-BIS twice within 1 week. Psychometric evaluation of the swe-BIS included assessment of different indices of reliability (internal consistency, test-retest and agreement) and validity (response processess, divergent and convergent). Confirmatory factor analyses (CFA) were performed to assess several indices of model fit in five different models based on previously suggested subscales. RESULTS: Cronbach's alpha for all swe-BIS items in the full sample was 0.89, ranging from 0.78-0.87 within the different subgroups. The Pearson test-retest correlation for total score was 0.78 (p < 0.001), with greater test-retest correlations within compared to across different subscales. The Bland-Altman plot indicated high level of agreement between test and retest. The healthy individuals had lower swe-BIS score compared to the patients (t(267.3) = - 8.6; p < 0.001), and the swe-BIS total score was also significantly different between each of the four participant groups (p < 0.01 for all group comparisons). Furthermore, swe-BIS had greater correlations with impulsivity related scales compared to non-impulsivity related scales. The CFA analyses indicated that while no suggested model showed an optimal fit, the best model fit indices was found for the 3-factor model. CONCLUSIONS: The swe-BIS was found to have good to excellent psychometric properties with respect to the assessed indices of reliability and validity, supporting use of the scale in clinical research in both healthy individuals and patients with SUD and ADHD.