A comparison of six approaches for measuring utility values among patients with locally advanced cervical cancer

ABSTRACT

Background

Several instruments are available to measure health utility values. However, limited studies have not yet comprehensively assessed the agreement among these instruments. This study therefore aimed to investigate the performance and agreement of six instruments for utility measures: EQ-5D-3L, EQ-5D-5L (cTTO model), EQ-5D-5L (DCE model), EQ-5D-5L (Hybrid model), TTO, and VAS, among locally advanced cervical cancer (LACC) patients in Thailand.

Methods

We compared utility scores derived from six approaches using Friedman's test. We also assessed the agreement of utility scores between each pairwise comparison by intraclass correlation coefficient (ICC) and Bland–Altman plot.

Results

The mean (SD) utility values derived from six approaches were as follows: 0.755 ± 0.248 (EQ-5D-3L), 0.801 ± 280 (TTO), 0.806 ± 0.156 (VAS), 0.871 ± 0.184 (cTTO model), 0.875 ± 0.168 (Hybrid model), and 0.900 ± 0.142 (DCE model). Significant differences across six approaches were found in Friedman's test. The ICC showed high agreement between EQ-5D-5L and EQ-5D-3L, and very high agreement between all three models of EQ-5D-5L. The Bland-Altman plots showed wide limit of agreement, except the pairwise comparison, between each model of the EQ-5D-5L.

Conclusion

TTO, VAS, EQ-5D-3L and EQ-5D-5L could not be used interchangeably in LACC patients. The impact of using different instruments on economic evaluation findings warrants further investigation.

KEYWORDS:

• Cervical cancer
• utility
• agreement
• EQ-5D
• TTO
• VAS

Reviewer disclosure

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.

Authors’ contributions

All authors contributed to the study conception and design. Data collection was conducted by KK. Data analysis was conducted by KK and MT. The first draft of the manuscript was written by KK. All authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Data availability statement

The datasets generated during and/or analyzed during this study are available from the corresponding author, MT, upon reasonable request.

Ethics approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the responsible committee on human experimentation and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standard. The study was approved by the Mahidol University Institutional Review Board (MU-IRB 2019/030.1705), the Institutional Review Board of the Faculty of Medicine Vajira Hospital (IRB COA 039/62) and Research Committee of National Cancer Institute of Thailand (EC COA 044/2019). Participants’ identity was concealed in the publication. Data present in the publication are anonymous.

Acknowledgments

This study was a part of a PhD thesis of the first author at the Social, Economic and Administrative Pharmacy (SEAP) Graduate Program, Faculty of Pharmacy, Mahidol University. We would like to express our thanks to the EuroQoL group for allowing us to use the EQ-5D questionnaires. We thank all members of the Radiation Oncology at the Faculty of Medicine Vajira Hospital and the National Cancer Institute of Thailand for their contribution to the parts of the medical record service. Special thanks also to all patients who participated in the data collection process.

Disclosure statement

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This paper was not funded.