Table 2 Overview of EQ-5D-Y valuation studies which are published, data collection completed, underway

Japan

Published—see Shiroiwa et al. [13]

cTTO designs with five blocks each with six health states; Same sample completed both DCE and cTTO tasks in face-to-face interviews

Mapping DCE data onto the cTTO data

Slovenia

Published—see Prevolnik-Rupel et al. [12]

Standard

DCE included an adolescent sample aged between 11 and 17 years [23]

Rescaling based on the single state “33333”

Spain

Published—see Ramos-Goni et al. [14]

cTTO tasks switched from face-to-face to online settings part-way through

DCE included an adolescent sample aged between 11 and 17 years [23]

Rescaling based on the single state “33333”

Germany

Published—see Kreimeier et al. [15]

cTTO tasks switched from face-to-face to online settings part-way through

DCE also included in cTTO interviews to compare interview-based and online DCE results; DCE included an adolescent sample aged between 11 and 17 years [23]

Mapping DCE data onto the cTTO data*

Belgium

Data collection completed

cTTO tasks switched from face-to-face to online settings part-way through

Additional DCE respondents were included, whom completed tasks from the perspective of a child (8–12 years old) and adolescents (13–18 years old)

Rescaling based on the single state “33333”*

China (Mainland)

Date collection completed

Expanded cTTO design to allow possibility of modelling cTTO-only value set (a small orthogonal design with 18 states + 10 from protocol)

Methods to be determined

Hong Kong

Date collection completed

both DCE and cTTO tasks administered in face-to-face CAPI

DCE and cTTO tasks using two perspectives: a child (10 year old) and adult’s own perspective

Methods to be determined

Hungary

Data collection completed

Standard

Additional four TTO tasks using adult’s own perspective

Rescaling based on the single state “33333”*

Indonesia

Data collection completed

Expanded TTO design (18 health states arranged orthogonal design + 5 suggested states + 2 states with higher level sum score)

Mapping DCE data onto the cTTO data*

Paper-and-pencil survey for DCE

Netherlands

Data collection completed

Expanded TTO design to allow possibility of modelling TTO-only value set (28 states divided into 3 blocks of 10 stats each; 33333 and at least one mild state in each block); cTTO tasks completed in online settings

An additional cTTO sample (n = 203) was collected, in which the cTTO task was framed asking respondents to indicate what they think a 10 year-old child would prefer

Different approaches used, including (1) Rescaling based on the single state “33333” and (2) mapping DCE data onto cTTO data

Australia

Underway

Expanded cTTO design to allow possibility of modelling cTTO-only value set; cTTO tasks planned in online settings

Additional DCE with duration and DCE with dead tasks

Different approaches planned:

(1) Rescaling based on the single state “33333”; and using other health states in cTTO as the sole anchor

(2) Mapping DCE data onto cTTO data

(3) using DCE with duration; (4) using DCE with dead questions

US

Underway

Preparatory work underway

Brazil

Underway

Preparatory work underway

Malaysia⁺

Underway

In all four cases, an expanded cTTO design to allow possibility of modelling cTTO-only value set (a small orthogonal design with 18 states + 10 from protocol)

A pilot DCE study of 400 individuals in each country/region, who will be randomised to the perspective of a hypothetical child from the following age groups: “5–7 years old”, “8–10 years old”, “11–13 years old” and “14–15 years old”

Different approaches planned:

Singapore⁺

Underway

Taiwan⁺

Underway

(1) Rescaling based on the single state “33333”

Vietnam⁺

Underway

(2) Mapping DCE data onto cTTO data

(3) a hybrid model