Development and Content Validation of ISARA: An Indian Scale for Assessment of (Sensory) Reactivity in Autism Spectrum Disorder

Introduction: Children with autism spectrum disorder (ASD) often exhibit atypical sensory responses, including hyper-reactivity, hypo-reactivity, and sensory-seeking behaviors. Assessing the severity of these patterns is essential for early identification, individualized intervention, and progress monitoring. Although several international measures exist, culturally relevant and context-specific tools are necessary for accurate assessment in the Indian context. This study aimed to develop and conduct content validation of the Indian Scale for Assessment of Sensory Reactivity in Autism (ISARA). Materials and Methods: A two-phase mixed-method design was employed. An in-depth interview (IDI) guide was developed through a literature review and reference to existing sensory reactivity scales. It was refined with expert input from psychiatrists, child psychologists, speech-language pathologists, and occupational therapists experienced in ASD care. IDIs were conducted with parents ( n = 20), audio-recorded, transcribed, and translated from Hindi to English. Manual coding and thematic analysis identified emerging sensory reactivity patterns. Experts evaluated face validity, followed by qualitative feedback to refine items. Item-level content validity ratio (I-CVR), Domain-level Content Validity Index (D-CVI) and Scale-level Content Validity Index (S-CVI) were computed for content validation. Results: Thematic analysis yielded four domains: sensory hyper-reactivity, sensory hypo-reactivity, sensory-seeking, and attentional and socio-emotional response. Sixty-three items (I-CVR = 0.8–1.0) were retained. D-CVI ranged from 0.83 to 0.92, indicating good to excellent validity, with an overall S-CVI of 0.86. Discussion: ISARA demonstrated strong content validity and cultural relevance for assessing sensory reactivity in Indian children with ASD, providing a foundation for further psychometric validation in larger samples. Future research will focus on establishing the psychometric robustness of ISARA.