Health utilities of patients with epilepsy in a Canadian population.

Objective: Health state utilities are required to obtain quality adjusted life years, a common metric that informs clinical decision-making at individual, group, and health policy levels. Health state utilities are different from health-related quality of life, and their distribution across patients with epilepsy, as well as the factors that impact them, have not been studied in depth. We aimed to describe the distribution of health state utilities in people with epilepsy and the impact of different combinations of clinical and demographic factors on health state evaluation.

Methods: We performed a retrospective analysis of patients' data prospectively collected in the Calgary Comprehensive Epilepsy Program registry. Patient-reported health state utilities were measured using the 5-level EuroQol 5-Dimension scale (EQ-5D-5L) completed at their initial assessment. EQ-5D-5L index scores were derived via the time trade-off approach based on Canadian norms, and their distribution across different health states and patient characteristics was obtained. The Tobit regression model was used to evaluate the determinants of EQ-5D-5L index scores.

Results: Of 1446 patients included in this analysis, 724 (50.5%) were female. The median (interquartile range) Canada-normed EQ-5D-5L index score was .87 (.71-.91). Patients with significantly lower health utilities were more likely to be female (p = .008), to be older (p = .034), to be unmarried (p = .013), to have failed to achieve 1-year seizure freedom (p < .001), to have no postsecondary education (p = .028), to be depressed (p < .001), to have antiseizure medication side effects (p = .001), to be unemployed (p < .001), and to be unable to drive (p < .001). A look-up table of health utilities based on combinations of clinical-demographic characteristics was produced.

Significance: Health utility estimates for combinations of different health states in people with epilepsy attending specialty clinics are now available. These can help guide clinical decision-making in routine clinical practice, economic evaluations of treatment interventions, and health care policies.