Face and Content Validation of the Childhood Autism Prognosis (CAP) Score: A Novel Quality-of-Life Assessment Tool for Indian Children with Autism Spectrum Disorder

Background: Autism Spectrum Disorder (ASD) affects ~1 in 100 Indian children, but culturally relevant tools to monitor treatment-related Quality-of-Life (QoL) outcomes are scarce. Existing scales focus on diagnosis or symptom severity rather than longitudinal functional change. The Childhood Autism Prognosis (CAP) Score is a 34-item QoL tool designed for use by clinicians, therapists and caregivers in Indian settings. This study reports its face and content validity. Methods: A multidisciplinary panel of six ASD experts (developmental paediatricians, paediatric neurologist, clinical psychologists) evaluated the CAP Score. Face validity was assessed for clarity, relevance and language using a 4-point Likert scale. Item-Level Face Validity Index (I-FVI) and Scale-Level Face Validity Index (S-FVI) were calculated. Content validity was assessed for item relevance and essentiality via Item-Level Content Validity Index (I-CVI), Scale-Level CVI (S-CVI/Ave, S-CVI/UA) and Content Validity Ratio (CVR) using Lawshe’s method. Results: Face validity was excellent (S-FVI = 0.92); 82.35% of items had I-FVI = 1.00. Content validity indices were outstanding (mean I-CVI = 0.993, S-CVI/Ave ≥ 0.90). All items exceeded CVR thresholds (mean CVR = 0.971). No items were removed; minor wording refinements were suggested. Experts rated the tool highly feasible for quarterly administration in outpatient or community settings. Conclusion: The CAP Score demonstrates excellent clarity, relevance and cultural suitability for monitoring QoL in Indian children with ASD. These results support advancing to reliability, construct validity and responsiveness testing to establish it as a robust longitudinal outcome measure in autism care.