What does better look like in individuals with severe neurodevelopmental impairments? A qualitative descriptive study on SCN2A-related developmental and epileptic encephalopathy.

Purpose: There are limited psychometric data on outcome measures for children with Developmental Epileptic Encephalopathies (DEEs), beyond measuring seizures, and no data to describe meaningful change. This study aimed to explore parent perceptions of important differences in functional abilities that would guide their participation in clinical trials.

Methods: This was a descriptive qualitative study. Semi-structured one-on-one interviews were conducted with 10 families (15 parent participants) with a child with a SCN2A-DEE [8 male, median (range) age 7.5 (4.5-21)] years. Questions and probes sought to understand the child's functioning across four domains: gross motor, fine motor, communication, and activities of daily living. Additional probing questions sought to identify the smallest differences in the child's functioning for each domain that would be important to achieve, if enrolling in a traditional therapy clinical trial or in a gene therapy trial. Data were analyzed with directed content analysis.

Results: Expressed meaningful differences appeared to describe smaller developmental steps for children with more limited developmental skills and more complex developmental steps for children with less limited skills and were different for different clinical trial scenarios. Individual meaningful changes were described as important for the child's quality of life and to facilitate day-to-day caring.

Conclusion: Meaningful change thresholds have not been evaluated in the DEE literature. This study was a preliminary qualitative approach to inform future studies that will aim to determine quantitative values of change, applicable to groups and within-person, to inform interpretation of specific clinical outcome assessments in individuals with a DEE.