This study aims to validate the Arabic adaptation of the Naturalistic Observation Diagnostic Assessment (NODA), a telehealth tool designed to help diagnose Autism Spectrum Disorder (ASD) in young children. NODA guides parents to record home videos of their child in specific everyday situations, which are then reviewed remotely by trained clinicians. The study will compare the results from NODA video assessments to gold-standard in-person diagnostic evaluations. By testing the accuracy and feasibility of Arabic NODA in Saudi Arabia, this research may help improve access to early ASD diagnosis, especially for families in remote or underserved areas.

This cross-sectional diagnostic validation study evaluates the Arabic adaptation of the Naturalistic Observation Diagnostic Assessment (NODA), a smartphone-based telehealth diagnostic tool for Autism Spectrum Disorder (ASD). The study employs a systematic cultural adaptation methodology including forward translation, expert panel review, back-translation, cognitive interviewing, and pilot testing to ensure cultural appropriateness for Saudi populations.

The validation phase involves 200 children (100 with confirmed ASD diagnoses, 100 typically developing controls, ages 6 months to 6 years) recruited from autism centers and pediatric clinics in Riyadh, Saudi Arabia. Caregivers use the Arabic NODA smartphone application to record four standardized behavioral scenarios in their home environment: family mealtime, play with others, play alone, and parent-reported concerns.

Two licensed clinicians, blinded to participant diagnostic status, independently review all video submissions through a secure web portal and provide diagnostic determinations based on DSM-5 criteria. Primary analysis compares NODA-based diagnoses to gold-standard clinical evaluations established through comprehensive in-person assessments using standardized tools (ADOS-2, ADI-R). Statistical analysis includes calculation of sensitivity, specificity, predictive values, inter-rater reliability, and receiver operating characteristic curves to establish diagnostic accuracy metrics and assess clinical utility for telehealth ASD diagnosis in Arabic-speaking populations.

Inclusion Criteria:

• Age between 6 months and 6 years old
• For ASD group: Confirmed diagnosis of Autism Spectrum Disorder (ASD) based on DSM-5 criteria established through comprehensive clinical evaluation including standardized assessments (ADOS-2, ADI-R)
• For typically developing group: No developmental, behavioral, or academic concerns reported by parents or teachers; negative screening for ASD using Arabic Social Communication Questionnaire (SCQ)
• Parent or primary caregiver fluent in Arabic language
• Access to a smartphone with internet connectivity
• Ability to complete all four NODA video recording scenarios using the Arabic smartphone application

Exclusion Criteria:

• Significant visual or hearing impairments that would interfere with video-based behavioral assessment
• Major motor impairments that significantly limit the child's ability to interact socially or participate in video recording tasks
• Diagnosed genetic syndromes or neurological conditions unrelated to ASD
• Non-Arabic speaking household
• Inability to complete the required video recording protocol after training and support

Children aged 6 months to 6 years, including those with confirmed Autism Spectrum Disorder and typically developing controls. Participants are recruited from clinical autism centers, general pediatric clinics, and community settings in Riyadh, Saudi Arabia.

Individual participant data (IPD) will not be shared due to the sensitive nature of the data, which includes video recordings of young children in home environments. These materials are difficult to fully de-identify and are subject to strict ethical and privacy protections under local regulations and IRB oversight.