Italian adaptation of the Beaumont Behavioral Inventory (BBI): psychometric properties and clinical usability

Objective. Up to 50% of patients affected by amyotrophic lateral sclerosis (ALS) show behavioral changes within the spectrum of frontotemporal degeneration (FTD). Behavioral dysfunctions in ALS patients negatively impact on management, prognosis and survival. It is, thus, crucial to develop ALS-specific psychometric tools for early detecting alterations in behavior. This study aimed at investigating psychometric properties and feasibility of the Beaumont Behavioral Impairment (BBI), a proxy-report questionnaire designed to screen for FTD-like behavioral symptoms in ALS patients. Methods. Ninety ALS patients were compared to 100 healthy participants (HPs) on the BBI. ALS patients underwent clinical, cognitive, mood/anxiety and further behavioral (Frontal System Behavior Scale, FrSBe; Frontal Behavioral Inventory, FBI) evaluation. Validity, reliability, sensitivity and specificity of the BBI were assessed. Results. The BBI was significantly related to FrSBe and FBI scores, whereas not to other measures. A Principal Component Analysis yielded a mono-component structure; Cronbach's alpha was .93. The BBI proved to be sensitive to changes in behavior as well as to discriminate between different degrees of dysfunction. By addressing the FrSBe as the gold standard, the BBI reached optimal sensitivity (85.7%) and specificity (79.7%) at a cutoff of 10.5. Moreover, the BBI proved to be more accurate than the FrSBe and the FBI in clinical classifications. Conclusion. The BBI showed high internal consistency, as well as good construct, convergent and divergent validity. Its clinical usability is encouraged in ALS patients as being able to sensitively and specifically detect FTD-like behavioral changes.