Authors :
Presenting Author: Elizabeth Donner, MD, FRCPC – Comprehensive Epilepsy Program, Division of Neurology, Hospital for Sick Children
Tracy Dixon-Salazar, PhD – Lennox-Gastaut Syndrome (LGS) Foundation
Jaya Khushalani, MD, PhD – UCB
Daniel Lloyd, BS – UCB
Heidi Henninger, MD – UCB
Marcus Brunnert, PhD – UCB
Wesley Kerr, MD, PhD – University of Pittsburgh Neurology
Rationale:
Patients with LGS or DS are at risk of premature mortality. Previous studies have reported mortality rates in DS; however, there are limited mortality data in LGS. Here, we used US claims data linked with a mortality database to examine mortality rates and patient-related characteristics in patients with LGS or DS.Methods:
This retrospective study used the Komodo database from 1/1/2015–12/31/2024. Patients were included if they had ≥2 LGS (ICD-10, G40.81) or DS (ICD-10, G40.83) claims ≥1 month apart in the patient qualification period (1/1/2015–12/31/2023) and 12 months of pre-index data. The index date was 1/1/2018 or the second LGS or DS claim date (if claim date ≥30 days after first claim), whichever occurred later. Study exit date was date of death, last recorded claim, or study end date of 12/31/2024.
The primary objective was to evaluate LGS and DS mortality rates; the secondary objective was to evaluate demographic and clinical characteristics associated with mortality. LGS and DS mortality rates per 1000 person-years (PY) and standardized mortality ratios (SMRs) were stratified by age (pediatric vs adult) and healthcare resource utilization (HCRU) severity score. HCRU severity score is an unvalidated weighted composite score of several HCRU elements (emergency room visits, admissions, and others).
Kaplan–Meier survival analysis was used to describe age-related survival probability. A Cox proportional hazards model was used to evaluate the association between mortality and demographic and clinical characteristics.
Results:
Overall, 33,404 and 2781 patients with LGS and DS were identified, respectively. Mortality rates (95% CI) in LGS and DS were 14.2 (13.6; 14.8) and 7.3 (5.6; 9.4) per 1000 PY, respectively; SMRs were 7.5 (7.2; 7.8) and 7.8 (6.0; 10.1), respectively. In LGS, pediatric (< 18 years; n=16,984) and adult (≥18 years; n=16,420) rates were 12.1 (11.3; 12.9) and 16.3 (15.4; 17.2) per 1000 PY, respectively. In DS, pediatric (n=2045) and adult (n=736) rates were 6.7 (4.8; 9.1) and 9.1 (5.5; 14.2) per 1000 PY, respectively. In both LGS and DS, SMRs were higher in pediatric patients vs adults. A trend for higher mortality rates and SMRs was observed in patients with higher HCRU severity scores. Age-related survival probability is shown in Figure. For the total cohort including LGS and DS populations, the Cox model indicated associations with mortality (P< 0.05) for clinical characteristics such as sleep apnea, gastrointestinal issues, wheelchair use, cardiovascular/respiratory issues, Charlson and Germaine Smith Comorbidity Indices, and demographic characteristics such as Area Deprivation Index and certain races/ethnicities.