Development and Validation of the Autism Behavior Assessment Scale (ABAS)

Area of Science:

• Neurodevelopmental Disorders
• Psychometrics
• Clinical Psychology

Background:

• Autism Spectrum Disorder (ASD) presents diverse neurodevelopmental challenges.
• Timely ASD diagnosis in Türkiye is hindered by a lack of culturally relevant assessment tools.
• Existing tools may not possess adequate psychometric properties for the Turkish population.

Purpose of the Study:

• To develop and validate the Autism Behavior Assessment Scale (ABAS) for individuals aged 3-24 years in Türkiye.
• To establish ABAS as a reliable and culturally adapted instrument for assessing ASD-related behaviors.
• To provide a psychometrically robust tool to aid in early ASD detection and intervention planning.

Main Methods:

• A nine-step scale development framework was utilized, involving 1275 informants across 14 Turkish provinces.
• The Autism Behavior Assessment Scale (ABAS) consists of 36 items across four subscales: RRBSS, SI, SC, and NDS.
• Psychometric validation included exploratory/confirmatory factor analysis, reliability testing, and comparison with established instruments like GARS-2-TV and U-ODKL.

Main Results:

• Confirmatory factor analysis confirmed a robust four-factor structure for the ABAS.
• The scale demonstrated excellent internal consistency (α = 0.91-0.96) and strong test-retest reliability (r = 0.83).
• High criterion validity (r = 0.93 with GARS-2-TV; r = 0.84 with U-ODKL) and discriminant validity (AUC = 0.99) were observed, differentiating ASD from ID and hearing impairments.

Conclusions:

• The Autism Behavior Assessment Scale (ABAS) is a psychometrically sound and culturally adapted instrument for ASD assessment in Türkiye.
• ABAS is developmentally sensitive, suitable for identifying and monitoring ASD-related behaviors in individuals aged 3-24 years.
• This validated scale is expected to enhance early ASD detection and inform educational and clinical interventions within the Turkish context.