INCLEN Diagnostic Tool for Autism Spectrum Disorder (INDT-ASD): development and validation

Area of Science:

• Pediatric Neurology
• Developmental Pediatrics
• Psychometrics

Background:

• Autism Spectrum Disorder (ASD) diagnosis in children requires validated tools for early intervention.
• Existing diagnostic methods may have limitations in accessibility or accuracy in diverse settings.

Purpose of the Study:

• To develop and validate the INCLEN Diagnostic Tool for Autism Spectrum Disorder (INDT-ASD).
• To assess the psychometric properties of INDT-ASD for diagnosing ASD in children aged 2-9 years.

Main Methods:

• Cross-sectional diagnostic test evaluation conducted in four tertiary pediatric neurology centers in India.
• INDT-ASD and Childhood Autism Rating Scale (CARS) administered by trained psychologists, with expert evaluation using DSM-IV-TR criteria as the gold standard.
• Analysis of diagnostic accuracy, validity (construct, criterion, convergent), and internal consistency.

Main Results:

• The INDT-ASD showed high diagnostic accuracy (AUC=0.97) and validity (sensitivity 98%, specificity 95%) compared to expert diagnosis.
• Excellent concordance between INDT-ASD and expert diagnosis (Cohen's k=0.89).
• High internal consistency (0.96), significant convergent validity with CARS (r=0.73), and divergent validity with intelligence tests (r=-0.37).

Conclusions:

• INDT-ASD is a validated tool with high diagnostic accuracy for identifying Autism Spectrum Disorder.
• The tool exhibits adequate content validity, good internal consistency, and high criterion validity.
• INDT-ASD demonstrates robust 4-factor construct validity, making it suitable for clinical use in diagnosing ASD.