Abstracts

Rationale: Focal epilepsy (FE) can be a debilitating condition that negatively impacts a person’s health-related quality of life (HRQoL).  Several studies have been published on HRQoLin people with FE (PWFE) however the determinants of HRQoL have not been comprehensively examined.  This systematic literature review (SLR) queries the existing literature to identify aspects associated with HRQoL in PWFE.  One objective is to identify modifiable determinants to inform potential measure selection for medical and non-medical interventions.

Methods: The SLR was conducted in accordance with PRISMA guidelines, including the application of PICOS criteria.  Searches were conducted in PubMed and Google Scholar for articles reporting on the association between HRQoL or employability and a range of demographic, psychosocial, or epilepsy-related factors and medical comorbidities in PWFE.  A total of 879 abstracts were retrieved and screened by two independent reviewers.  After full review of 126 manuscripts, 48 were selected for inclusion.  Studies that quantified the relationship between HRQoL and the variable of interest by multivariate (N=25) or univariate (N=22) methods were included; one study examined the relationship between employability and seizure type.  The reported findings herein are limited to the 25 multivariate models examining HRQoL.

Results: Overall, the studies examined a broad range of determinant of HRQoL.  These included mood (depression, anxiety), epilepsy-related factors (seizure frequency, number of anti-seizure medications used, adverse event burden, disease duration, age of onset) and cognition.   Unique topics were also explored in individual studies, such as religion or stigma.  The Quality of Life in Epilepsy-31 (QOLIE-31) was the most frequently used HRQoL measure (N=19/25 studies); temporal lobe epilepsy (TLE) the most common subset of FE studied.   Depression was the most frequently studied determinant, examined in N=14 of 25 studies and associated with lower HRQoL 86% of the time (N=12 studies).  Anxiety was another frequently reported determinant, examined in 8 studies and significantly associated with lower HRQoL in 7 of them.  Employment was identified as an important consideration for HRQoL, with significance in all studies where it was examined (N=5).  Seizure burden was frequently examined (N=14/25 studies).  However only when dichotomized into seizure freedom vs experiencing seizures (by Engel class I vs II, III and IV) did it reach significance, notably every time (N=4 studies).  When seizure burden was examined as a continuous variable (N=10/25 studies) it was rarely significant (N=1 study). The relationship between depression and HRQoL was the strongest among those assessed in a majority of the studies.

Conclusions: Comprehensive understanding of the modifiable determinants of HRQoL is relevant to patient health and well-being and can inform everyday clinical care, interventional and observational studies.

Funding: Study was funded by Biohaven Pharmaceuticals, Inc.