Epidemiology and Burden of Illness of Lennox-Gastaut Syndrome in Taiwan: A Retrospective Cohort Study

Purpose: Examine the epidemiology and burden of illness of patients with Lennox-Gastaut syndrome (LGS) in Taiwan. Methods: The National Health Insurance Database (NHID) was used, complemented by the Chang Gung Research Database (CGRD). Confirmed LGS was defined by International Classification of Diseases-10 (ICD-10) LGS codes or ≥1 rufinamide prescription; probable LGS was defined as patients aged ≤10 years when receiving ≥3 antiseizure medications (ASMs), with ICD-9/10 codes for developmental delay. Independent clinical review/validation of all LGS cases in the CGRD was conducted. Prevalence, incidence, time to treatment/LGS diagnosis, hospitalizations, costs (US dollars), ASM usage, and mortality were assessed. For the NHID, a positive predicted value (PPV) was calculated from the CGRD validation step to adjust prevalence/incidence estimates. Results: In the NHID, 190 patients with confirmed LGS were identified. In 2018, PPV-adjusted prevalence was 2.4, 0.6, and 10.2 per 100,000 people and PPV-adjusted incidence was 0.6, 0.2, and 2.4 per 100,000 person-years in the total, adult, and pediatric populations, respectively. Of 92 (48%) hospitalized patients, 22 (24%) had ≥3 hospitalizations/year. Mean (standard deviation [SD]) time to treatment and LGS diagnosis were 12.3 (26.5) and 110.1 (54.7) months. Mean length of stay was around 12 days. Most hospitalizations (96%) were epilepsy related. Mean (SD) hospitalization cost was $237 ($216) per day. Mean (SD) total inpatient and outpatient costs were $5800 ($817) and $2667 ($132), respectively, per patient per year (PPPY); medication in hospital and ASM costs were $1910 ($108) and $1614 ($93) PPPY. Most prescribed ASMs were valproate (89%), levetiracetam (83%), clonazepam (69%), clobazam (68%), and topiramate (65%). Mortality was 0.01 deaths per 100,000 people in 2018. Conclusion: Although prevalence and incidence of LGS in Taiwan were lower than in other countries, the multifaceted burden of illness in LGS is highlighted herein. Reduced hospitalizations through better epilepsy control may reduce LGS expenditure.