Value-Based Assessment of Clinical Trial Outcomes: A Hypothetical Example Using the Childhood Autism Rating Scale in Autism Spectrum Disorder
Durno N1, Heisen M2, Penton H2, Schmid R3, Ethgen O4, Szilvasy Z5, Friedel E6, Wong O7, Charman T8, San José Cáceres A9, Mühlbacher AC10, Van Hout BA11, Brazier JE11, Stolk E12
1OPEN Health Evidence & Access, Oxford, UK, 2OPEN Health Evidence & Access, Rotterdam, Netherlands, 3Les Laboratoires Servier, Suresnes, France, 4University of Liège, Liège, Belgium, 5Autism-Europe, Budapest, Hungary, 6Autism-Europe, Paris, France, 7Medi-Qualité Omega, Paris, France, 8King’s College London, London, UK, 9Instituto de Investigación Sanitaria del Hospital General Universitario Gregorio Marañón, Madrid, Spain, 10Hochschule Neubrandenburg, Neubrandenburg, Germany, 11University of Sheffield, Sheffield, UK, 12EuroQol Research Foundation, Rotterdam, Netherlands
OBJECTIVES: This research explores the application of patient preferences, as estimated by a discrete choice experiment (DCE), to hypothetical clinical trial results in childhood autism spectrum disorder (ASD), as measured by (between-group) changes from baseline. In childhood ASD, the Childhood Autism Rating Scale–2nd edition (CARS2) instrument is used to assess severity and change.
METHODS: A DCE was conducted, estimating the value of improvements within the standard version of CARS2, i.e. CARS2-ST. Caregivers were asked to participate, expressing preferences from the perspective of the child. As such, “utility” values were obtained for CARS2-ST-based profiles. Subsequently, hypothetical changes in CARS2-ST were simulated, as if measured in a trial, and the corresponding results in terms of “utility” were analysed: (1) A 3-point improvement was applied to a single patient; (2) A 3-point average group improvement was simulated under 3 conditions, wherein the improvement was derived randomly across the CARS2-ST, derived from the 6 attributes with the greatest preferences, and derived from the 6 attributes with the lowest preferences.
RESULTS: For one patient, a 3-point improvement in the CARS2-ST, increased the CARS2-ST numeric score by 6.5%; however, the latent utility function increased by 21% when this concerned the attributes with highest preference weights; and 6.3% when this concerned the attributes with the lowest preference weights. Using simulated trial data, the three scenarios resulted in very different impacts on latent utility. Depending on the source of CARS2-ST improvement, there was substantial variation in the value to patients.
CONCLUSIONS: The assessment of clinical trial measures should, where possible, account for the preferences of relevant groups, e.g., patients, caregivers and clinicians. Conclusions made from non-preference-based scoring alone can hide meaningful information on how a treatment will affect a patient’s health-related quality of life.
Conference/Value in Health Info
Value in Health, Volume 25, Issue 12S (December 2022)
Patient-reported Outcomes & Quality of Life Outcomes, Stated Preference & Patient Satisfaction