The impact of seizure frequency on quality of life in patients with Lennox-Gastaut syndrome or Dravet syndrome.

OBJECTIVES

Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are rare treatment-resistant epileptic encephalopathies with limited data describing the relationship between seizures and quality of life (QoL). The objective of this cross-sectional pilot study was to assess the impact on QoL of seizures and seizure-free days for the generation of utility values.

METHODS

Surveys were conducted in the UK and France, whereby patients and/or caregivers of patients with LGS, DS, or other epilepsies were asked to score health state vignettes for a hypothetical patient with LGS or DS. Respondents evaluated QoL for health states based on the number of seizures and seizure-free days per month, using a visual analog scale (VAS). Visual analog scale scores were converted to the 0-1 scale as a proxy estimate for utility values. Surveys were pilot tested and respondents were recruited from October 2018 to August 2019.

RESULTS

Patient respondents were mainly treatment-responsive (n = 43/55) whereas caregiver respondents mainly cared for patients with treatment-resistant epilepsy (n = 38/43). Most respondents and patients were aged ≥18 years. Results from LGS and DS surveys in the UK (n = 58) and France (n = 40) suggested that health states with fewer seizures and more seizure-free days had higher QoL scores for hypothetical patients. For DS, QoL scores for patient health states ranged from 0.20 (32 convulsive seizures and 4 seizure-free days/month, UK) to 0.92 (seizure-free, France). For LGS, scores ranged from 0.14 (130 drop seizures and 1 seizure-free day/month, France) to 0.83 (seizure-free, UK). In all surveys, seizure-free days had a greater impact on QoL than seizure frequency (P < 0.001).

CONCLUSIONS

Fewer seizures and additional seizure-free days improved QoL in patients with LGS or DS; seizure-free days had the greatest impact on QoL.