Impacts of the preceding cancer-specific health-related quality of life instruments on the responses to the subsequent EQ-5D-5L

Shoki Izumi; Yasuhiro Hagiwara; Yutaka Matsuyama; Takeru Shiroiwa; Naruto Taira; Takuya Kawahara; Keiko Konomura; Shinichi Noto; Takashi Fukuda; Kojiro Shimozuma

doi:10.1186/s12955-022-02085-8

Impacts of the preceding cancer-specific health-related quality of life instruments on the responses to the subsequent EQ-5D-5L

Health Qual Life Outcomes. 2023 Jan 17;21(1):3. doi: 10.1186/s12955-022-02085-8.

Authors

Affiliations

¹ Biostatistics and Bioinformatics Course, Graduate School of Interdisciplinary Information Studies, The University of Tokyo, Tokyo, Japan.
² Department of Biostatistics, School of Public Health, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. hagiwara@epistat.m.u-tokyo.ac.jp.
³ Department of Biostatistics, School of Public Health, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
⁴ Center for Outcomes Research and Economic Evaluation for Health, National Institute of Public Health, Wako, Japan.
⁵ Department of Breast and Endocrine Surgery, Okayama University Hospital, Okayama, Japan.
⁶ Clinical Research Promotion Center, The University of Tokyo Hospital, Tokyo, Japan.
⁷ Center for Health Economics and QOL Research, Niigata University of Health and Welfare, Niigata, Japan.
⁸ Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan.

Abstract

Background: In clinical studies, the EQ-5D-5L is often employed with disease-specific health-related quality of life instruments. The questions in the former are more general than the latter; however, it is known that responses to general questions can be influenced by preceding specific questions. Thus, the responses to the EQ-5D-5L have the possibility of being influenced by the preceding disease-specific health-related quality of life instruments. This may lead to bias in the cost-effectiveness analysis results. Therefore, this study aimed to evaluate the impact of the preceding cancer-specific health-related quality of life instruments on the EQ-5D-5L responses.

Methods: We prepared questionnaire booklets containing the EQ-5D-5L, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, and the Functional Assessment of Cancer Therapy General with different orders. Using a quasi-randomized design, they were distributed to the patients undergoing drug therapy for advanced cancer, who were classified into three groups: Groups 1, 2, and 3 (the EQ-5D-5L placed first, second, and last, respectively). We compared the EQ-5D-5L index and the missingness of EQ-5D-5L among the groups.

Results: The mean EQ-5D-5L index was 0.796, 0.760, and 0.789 for groups 1 (n = 300), 2 (n = 306), and 3 (n = 331), respectively. The difference between Groups 2 and 1 was - 0.036 (95% CI - 0.065 to - 0.007; p = 0.015). The proportion of patients with an incomplete EQ-5D-5L was 0.11, 0.11, and 0.05 for Groups 1, 2, and 3, respectively. The difference of the proportions between group 3 and 1 and between 3 and 2 was - 0.06 (95% CI - 0.10 to - 0.02; p = 0.003) and - 0.06 (95% CI - 0.10 to - 0.02; p = 0.003), respectively.

Conclusions: Although the EQ-5D-5L index differed according to the instrument orders, the difference size would not be considerably larger than the minimally important difference. The patients tended to complete the EQ-5D-5L when they were placed at the end of the questionnaire.

Keywords: Cost-effectiveness analysis; EORTC QLQ-C30; EQ-5D-5L; FACT-G; Health-related quality of life; Order effect.

Publication types

Randomized Controlled Trial

MeSH terms

Humans
Neoplasms*
Quality of Life*
Reproducibility of Results
Surveys and Questionnaires*