NDD-ECHO: A standardised digital assessment tool to capture early life environmental and inflammatory factors for children with neurodevelopmental disorders.

Neurodevelopmental disorders (NDDs), such as autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), and Tourette syndrome are highly prevalent in childhood and are influenced by both genetic and environmental factors. The maternal immune activation (MIA) hypothesis suggests that inflammation during pregnancy can increase the risk of NDDs in offspring. However, current practice focuses mainly on capturing family history of neurodevelopmental and psychiatric disorders. Beyond this, capturing detailed early life environmental data in clinical settings remains challenging. To address this, we developed NDD-ECHO (Neurodevelopmental Disorders-Environmental and Clinical History Online), a standardised digital assessment tool designed to systematically collect maternal and child environmental histories, alongside neurodevelopmental symptom profiles. NDD-ECHO is designed to collaboratively collect information from caregivers with clinician input, covering family medical history, maternal pregnancy history and environmental exposures, child's environmental exposures (including infection) and child's diagnosis, clinical course, and function. The survey, built on the REDCap platform, was piloted in a cohort of 161 children with complex NDDs referred to a tertiary neurodevelopmental clinic. Our results demonstrate that nearly 80 % of children experienced loss of developmental skills, and many had symptom exacerbations triggered by infections or stress, supporting the role of environmental factors in NDD symptomatology. NDD-ECHO, available for free download via the REDCap Shared Library, has clinical and research applications, enabling standardised identification of environmental triggers and exploration of gene-environment interactions. This tool advances research by improving data collection on environmental risk factors and enhances personalised care for children with NDDs. Limitations include reliance on retrospective caregiver reports and the pilot cohort's specialised clinical setting, which may limit generalisability.