Patient and Caregiver Health State Utilities in Tuberous Sclerosis Complex

Abstract

Background Tuberous sclerosis complex (TSC) is a rare multisystem disorder often associated with treatment-resistant epilepsy. Cost-effectiveness analysis for new antiseizure medications typically requires health state utilities (HSUs) that reflect the burden of a given condition. Objective This study aimed to estimate HSUs, with a focus on valuing the impact of seizure type and seizure frequency on health-related quality of life (HRQL) for patients with TSC and their caregivers. Methods A targeted literature review and qualitative research with healthcare professionals and caregivers informed the development of health state vignettes describing the experience of living with TSC or caring for a child with TSC. Vignettes were evaluated in interviews with the UK general population using the time trade-off (TTO) method. Results Sixteen vignettes were developed describing patient HRQL ( n = 8) and caregiver HRQL ( n = 8). Two hundred interviews were conducted via online video calls due to COVID-19 pandemic restrictions. Two hundred participants evaluated the patient ( n = 100) and caregiver ( n = 100) health state vignettes. Estimated utility scores varied consistently according to seizure type and seizure frequency. Patient TTO utility scores ranged between −0.234 (highest seizure frequency and multiple seizure types) and 0.725 (seizure-free state). Caregiver TTO utility scores ranged from 0.221 to 0.905. Conclusions Findings highlight the substantial burden of living with TSC and caring for a child with TSC. Patient and caregiver burden was greater for generalised versus focal seizures. The burden was greatest for a combination of both seizure types and worsened with increasing seizure frequency. Supplementary Information The online version contains supplementary material available at 10.1007/s41669-021-00296-1.

A Cost-Utility Analysis of Add-On Cannabidiol Versus Usual Care Alone for the Treatment of Seizures Associated with Tuberous Sclerosis Complex in England and Wales

“…EQ-5D) do not strongly correlate with disease-specific measures for epilepsy [ 82 ]. To generate HRQL data for the model population, we conducted a vignette study in the general population using TTO methodology to elicit patient and caregiver HRQL, and the ICER was robust to scenario analysis using alternative sources of patient HRQL [ 22 , 48 , 70 ].…”

“…Categories for HCRU and HRQL were derived during the Delphi panel survey [ 45 ] (see Online Resource 1 in the ESM) and a vignette study (involving consultation with clinicians and caregivers), respectively (see Online Resource 2, Online Resource Tables 2–4 and Online Resource Figs. 1–3 in the ESM) [ 48 ].

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“…To calculate the QALYs associated with treatment, a vignette study using time trade-off (TTO) methods, valued by the UK general public, was conducted to generate utility weights for patients and their caregivers [ 48 ]. Vignette descriptions were designed to reflect the HRQL profile of people with TSC-associated epilepsy and their caregivers, and the TTO weights used are published elsewhere [ 48 ].…”

“…To calculate the QALYs associated with treatment, a vignette study using time trade-off (TTO) methods, valued by the UK general public, was conducted to generate utility weights for patients and their caregivers [ 48 ]. Vignette descriptions were designed to reflect the HRQL profile of people with TSC-associated epilepsy and their caregivers, and the TTO weights used are published elsewhere [ 48 ]. This analysis assumed an average of 1.8 caregivers per patient (with the exception of institutionalized patients where 1 caregiver per patient was assumed), consistent with the preferred assumptions in the economic appraisal of cannabidiol in TSC [ 33 ].…”