A Targeted Literature Review to Explore the Patient, Caregiver, and Family Member Experience of Dravet Syndrome and Lennox-Gastaut Syndrome

OBJECTIVES: A targeted literature review was conducted to identify published health utility data and explore symptoms and impacts of Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) on patients and caregivers/family members.

METHODS: Pre-defined search strategies, performed in Embase and MEDLINE databases, included searches for utility scores and qualitative/quantitative data focused on symptoms and impacts for patients and caregivers/family members. Searches for testimonials from patient advocacy groups describing DS or LGS experiences were also conducted.

RESULTS: Nine studies reported utility data for patients with DS or LGS (n=6) and/or caregivers (n=5). Most studies (7/9) used preference-based measures (EQ-5D-5L, EQ-5D-3L, Health Utilities Index [HUI]-2/3) rather than health states to derive DS population utility scores for patients (mean EQ-5D-5L, 0.33−0.72; overall HUI-2/3, 0.56/0.32) and caregivers (mean EQ-5D, 0.78−0.90). Two studies used vignette methods to derive utilities for health states in DS and LGS, which were rated using Time Trade Off and/or Visual Analogue Scale. Patient utility values ranged from 0.17−0.78 (DS) and -0.28−0.83 (LGS). Caregiver utility values ranged from 0.47−0.87 (DS) and -0.10−0.79 (LGS). Patient and caregiver utility values were lower with higher seizure frequency and fewer seizure-free days. Fifteen studies reported qualitative data and 38 reported quantitative data on patient symptoms (e.g., seizures, behavioural disturbance, motor dysfunction, cognitive impairment, communication issues, and sleep disturbance) and impacts (e.g., eating behaviour, emotional/psychological well-being, and social). Twelve studies reported qualitative data and 25 reported quantitative data on impacts on caregivers’ emotional/psychological well-being, work/finances, social life, family life, and relationships. Reported impacts aligned with findings from testimonials.

CONCLUSIONS: Patient and caregiver utility scores in DS and LGS were lower with increasing seizure frequency and decreasing seizure-free days, indicating substantial health-related quality-of-life impacts of DS and LGS. A variety of symptoms/impacts were identified, indicating significant burden of both conditions on patients’ and caregivers’ quality-of-life.