Does the Introduction of the Ranking Task in Valuation Studies Improve Data Quality and Reduce Inconsistencies? The Case of the EQ-5D-5L.
BACKGROUND
Time trade-off (TTO)-based valuation studies for the three-level version of the EuroQol five-dimensional questionnaire (EQ-5D) typically started off with a ranking task (ordering the health states by preference). This was not included in the protocol for the five-level EQ-5D (EQ-5D-5L) valuation study.


OBJECTIVE
To test whether reintroducing a ranking task before the composite TTO (C-TTO) could help to reduce inconsistencies in C-TTO responses and improve the data quality.


METHODS
Respondents were randomly assigned to three study arms. The control arm was the present EQ-5D-5L study protocol, without ranking. The second arm (ranking without sorting) preceded the present protocol by asking respondents to rank the target health states using physical cards. The states were then valued in random order using C-TTO. In the third arm (ranking and sorting), the ranked states remained visible through the C-TTO tasks and the order of valuation was determined by the ranking. The study used only 10 EQ-5D-5L health states. We compared the C-TTO-based inconsistent pairs of health states and ties.


RESULTS
The final sample size was 196 in the control arm, 205 in the ranking without sorting arm, and 199 in the ranking and sorting arm. The percentages of ties by respondents were 15.1%, 12.5%, and 12.6% for the control arm, the ranking without sorting arm, and the ranking and sorting arm, respectively. The extra cost for adding the ranking task was about 15%.


CONCLUSIONS
The benefit does not justify the effort involved in the ranking task. For this reason, the addition of the ranking task to the present EQ-5D-5L valuation protocol is not an attractive option.
EuroQol Research Foundation, Rotterdam, The Netherlands; Research Network on Health Services in Chronic Diseases, (REDISSEC), Madrid, Spain. Electronic address: juamanuel.ramosgoni@gmail.com.
Juan M
JM
Ramos-Goñi
Department of Health Management and Health Economics, University of Oslo, Oslo, Norway; Health Services Research Centre, Akershus University Hospital, Lørenskog, Norway.
Kim
K
Rand-Hendriksen
Economics Department, University of Navarra, Pamplona, Spain; Glasgow Caledonian University, Glasgow, Lanarkshire, UK.
Jose Luis
JL
Pinto-Prades
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D004185:Disability Evaluation; D005260:Female; D006304:Health Status; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D018434:Sickness Impact Profile; D013030:Spain; D011795:Surveys and Questionnaires; D055815:Young Adult
health related quality of life; ranking, EQ-5D-5L; time trade off; valuation