[The BSE2 scale : A new clinical tool for the diagnostic of ASD within NDDs]

The behavioral summarized evaluation scales, the BSE and its revised version the BSE-R, were developed and validated in the 1980-1990s. The BSE-R is still used daily by clinical teams in France and foreign countries, and it is recommended by the French Health Authority (2018). Having taken into account knowledge improvement in neurodevelopment and autism spectrum disorder (ASD) and the importance of observation by relatives in ecological context, the second version of the BSE was developed. This paper presents the construction and the validation study of the second version of the behavioral summarized evaluation scale, the BSE2 and the BSE2-P rated by parents.

Construct validity of the BSE2 scale has been studied in a population of 244 children and adolescents with ASD according to DSM-5 criteria, aged from 30 months to 18 years. Discriminant validity has been analyzed using a population of 86 patients of the same age, with neurodevelopmental disorder (NDD) without comorbidity of ASD.

BSE2 comprises 30 items and is a two-dimensional scale as was BSE-R. Both dimensions, labelled "Interaction" (11 items) and "Modulation" (11 items), accounted for 41.7 % of the total variance. They describe autism severity and are in accordance with the two DSM-5 dimensions. Internal consistency (0.927 and 0.850 respectively) and inter-rater reliability (0.932 and 0.897 respectively) are good or excellent for both dimensions. Sensibility and specificity (0.758 and 0.767 respectively) range BSE2 among the tools with good psychometric properties. The parent version, BSE2-P, dedicated to ecological context is easily rated by parents.

BSE2 scale for children and adolescents is a clinical tool with good psychometric properties. Its two-dimensional structure is in accordance with DSM-5 criteria. This scale covers all spectrum of ASD clinical forms in both children and adolescents. It can be used to identify ASD in complex neurodevelopmental disorders with several comorbidities and can help to distinguish autism symptomatology from other neurodevelopmental diagnoses. Furthermore, this scale allows to expand the rating context, involving parents to define and adjust the individualized therapeutic project. Thus the BSE2 is a valuable clinical tool for practitioners for both diagnosis and follow-up.