COMPARATIVE STUDY OF TTO-BASED, HYBRID, AND DCE WITH DURATION VALUE SETS FOR EQ-5D-5L IN QATAR
Author(s)
Bram Roudijk, PhD1, Anas Hamad, MSc, PhD2, Dina Abushanab, PhD3, Daoud Al-Badriyeh, PhD4, Samar Farid, PhD5, Caline Saade, PharmD6, Fatima Al Sayah, PhD6, Marcel Jonker, PhD7.
1EuroQol Research Foundation, Rotterdam, Netherlands, 2Drug Supply Department, Hamad Medical Corporation, Doha, Qatar, 3Office of Vice President for Medical and Health Sciences, QU Health, Qatar University, Doha, Qatar, 4College of Pharmacy, QU Health, Qatar University, Doha, Qatar, 5Cairo University, Cairo, Egypt, 6Center of Clinical, Health Economics and Outcomes Research, Dubai, United Arab Emirates, 7Erasmus School of Health Policy & Management, Rotterdam, Netherlands.
1EuroQol Research Foundation, Rotterdam, Netherlands, 2Drug Supply Department, Hamad Medical Corporation, Doha, Qatar, 3Office of Vice President for Medical and Health Sciences, QU Health, Qatar University, Doha, Qatar, 4College of Pharmacy, QU Health, Qatar University, Doha, Qatar, 5Cairo University, Cairo, Egypt, 6Center of Clinical, Health Economics and Outcomes Research, Dubai, United Arab Emirates, 7Erasmus School of Health Policy & Management, Rotterdam, Netherlands.
OBJECTIVES: This study aims to conduct a within-sample comparison of value sets derived from composite time-trade-off (cTTO)-based and discrete choice experiment with duration (DCEd) methodologies, in order to assess the consistency and agreement among these valuation approaches in generating value sets for the EQ-5D-5L instrument in Qatar.
METHODS: The study aims to recruit a sample of 1,000 adults residing in Qatar using an age and sex-based quota sampling strategy ensuring representation of both Qatari nationals and expatriates. The study follows a modified version of the EQ-VT valuation protocol, whereby DCEd replaced the traditional latent scale DCE. Each respondent completed a set of 10 cTTO tasks, 15 split triplet DCEd tasks where first choose between two health states of the same duration, followed by a choice between one of those two lives and being in full health for a shorter duration. The cTTO data were analyzed using a heteroskedastic Tobit model while the DCEd data were analyzed using a mixed logit model with exponential discounting. Agreement between the methods was assessed using Lin’s Concordance.
RESULTS: As of 26 June 2026, 444 participants have completed the interviews, with a mean (SD) age of 31.8 (10.9) years; 45.3% are female and 3.4% are Qatari nationals. Based on interim analysis, the correlation between the cTTO and DCEd estimates was high (r=0.977), while agreement was good (CCC=0.827). The ordering of dimensions was similar between the two methods, while the DCEd produced a longer scale range than cTTO (v(55555)=-0.973 in cTTO, while v(55555)=-1.5 in DCEd).
CONCLUSIONS: The study will add to the body of evidence on the comparative performance of the cTTO/EQ-VT approach vs. DCE with duration for generating a value set for the EQ-5D-5L, which will have significant implications of the valuation protocol in the future.
METHODS: The study aims to recruit a sample of 1,000 adults residing in Qatar using an age and sex-based quota sampling strategy ensuring representation of both Qatari nationals and expatriates. The study follows a modified version of the EQ-VT valuation protocol, whereby DCEd replaced the traditional latent scale DCE. Each respondent completed a set of 10 cTTO tasks, 15 split triplet DCEd tasks where first choose between two health states of the same duration, followed by a choice between one of those two lives and being in full health for a shorter duration. The cTTO data were analyzed using a heteroskedastic Tobit model while the DCEd data were analyzed using a mixed logit model with exponential discounting. Agreement between the methods was assessed using Lin’s Concordance.
RESULTS: As of 26 June 2026, 444 participants have completed the interviews, with a mean (SD) age of 31.8 (10.9) years; 45.3% are female and 3.4% are Qatari nationals. Based on interim analysis, the correlation between the cTTO and DCEd estimates was high (r=0.977), while agreement was good (CCC=0.827). The ordering of dimensions was similar between the two methods, while the DCEd produced a longer scale range than cTTO (v(55555)=-0.973 in cTTO, while v(55555)=-1.5 in DCEd).
CONCLUSIONS: The study will add to the body of evidence on the comparative performance of the cTTO/EQ-VT approach vs. DCE with duration for generating a value set for the EQ-5D-5L, which will have significant implications of the valuation protocol in the future.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
PCR212
Topic
Methodological & Statistical Research, Patient-Centered Research
Topic Subcategory
Patient-reported Outcomes & Quality of Life Outcomes
Disease
No Additional Disease & Conditions/Specialized Treatment Areas