Long-Term Clinical Burden, Treatment Patterns, and Healthcare Utilization in Children with Lennox–Gastaut Syndrome and Infantile Epileptic Spasms Syndrome: A Nationwide Population-Based Claims Study

Purpose: Lennox-Gastaut syndrome (LGS) and infantile epileptic spasms syndrome (IESS) are severe developmental epileptic encephalopathies associated with substantial treatment burden and healthcare utilization.This study characterized clinical features, treatment burden, complications, and healthcare utilization in a nationwide cohort of patients with LGS and IESS and examined differences according to clinical severity.Methods: We retrospectively analyzed patients diagnosed with LGS or IESS between January 2009 and December 2021 using a nationwide insurance claims database.Clinical characteristics, treatment burden, complications, and healthcare utilization were examined according to recorded intellectual disability (ID) and the operational definition of intractable epilepsy.Results: The analysis included 4,124 patients with LGS or IESS; 64.1% had a recorded diagnosis of ID and 51.2% met the operational definition of intractable epilepsy.The absence of these conditions in some patients' records indicated variability in documented long-term disease burden.Patients with intractable epilepsy had greater treatment burden and healthcare utilization, including the use of more antiseizure medications, more frequent surgical interventions, and higher frequencies of hospitalization, intensive care unit admission, and medical complications.Polypharmacy and healthcare burden increased over time, particularly in these patients.Conclusion: In this nationwide cohort, children with LGS and IESS had substantial treatment burden and healthcare utilization, with differences according to clinical severity.These findings may inform risk stratification and long-term management.