Abstract
Purpose
To compare the measurement precision and related properties between the 5-level EuroQoL Group’s 5-dimension (EQ-5D-5L) questionnaire and the Functional Assessment of Cancer Therapy—Breast (FACT-B) questionnaire in assessing breast cancer patients.
Methods
An observational study of 269 Singaporean breast cancer patients. To compare discriminative ability and responsiveness, the effect sizes (in standard deviation) of the EQ-5D-5L and the FACT-B in relation to health indicators and the change in performance status or quality of life were estimated. Test–retest reliability was examined using the intraclass correlation (ICC).
Results
Using performance status, evidence of disease, and treatment status as the criteria, the differences (FACT-B minus EQ-5D-5L) in the effect size for discriminative ability were negative or closed to zero, and the 90 % confidence intervals totally fell within the zone that indicated the non-inferiority of the EQ-5D-5L. For responsiveness and test–retest reliability, the confidence intervals of the differences in effect size and ICC overlapped the non-inferiority margin; thus, non-inferiority in these two aspects could neither be confirmed nor rejected.
Conclusions
The EQ-5D-5L was non-inferior to the FACT-B in discriminating breast cancer patients with different health conditions cross-sectionally. The EQ-5D-5L serves as a reasonable alternative or supplementary instrument to the FACT-B in assessing breast cancer patients’ health outcomes.
Abbreviations
- EQ-5D:
-
EuroQoL group’s 5-dimension questionnaire
- VAS:
-
Visual analog scale
- EQ-5D-3L:
-
3-level EuroQoL group’s 5-dimension questionnaire
- EQ-5D-5L:
-
5-level EuroQoL group’s 5-dimension questionnaire
- FACT-B:
-
Functional Assessment of Cancer Therapy—Breast
- QoL:
-
Quality of life
- TOI:
-
Trial Outcome Index
- ICC:
-
Intraclass correlation
- CI:
-
Confidence interval
References
Bernhard, J., Cella, D. F., Coates, A. S., Fallowfield, L., Ganz, P. A., Moinpour, C. M., et al. (1998). Missing quality of life data in cancer clinical trials: serious problems and challenges. Statistics in Medicine, 17(5–7), 517–532.
Axelsson, B., & Sjoden, P. O. (1999). Assessment of quality of life in palliative care: psychometric properties of a short questionnaire. Acta Oncologica, 38(2), 229–237.
Ballatori, E. (2001). Unsolved problems in evaluating the quality of life of cancer patients. Annals of Oncology, 12(Suppl 3), S11–S13.
Kopec, J. A., & Willison, K. D. (2003). A comparative review of four preference-weighted measures of health-related quality of life. Journal of Clinical Epidemiol, 56(4), 317–325.
Janssen, M. F., Birnie, E., & Bonsel, G. J. (2008). Quantification of the level descriptors for the standard EQ-5D three-level system and a five-level version according to two methods. Quality of Life Research, 17(3), 463–473.
Janssen, M. F., Birnie, E., Haagsma, J. A., & Bonsel, G. J. (2008). Comparing the standard EQ-5D three-level system with a five-level version. Value Health, 11(2), 275–284.
Sullivan, P. W., & Ghushchyan, V. (2006). Preference-based EQ-5D index scores for chronic conditions in the United States. Medical Decision Making, 26(4), 410–420.
Gao, F., Ng, G. Y., Cheung, Y. B., Thumboo, J., Pang, G., Koo, W. H., et al. (2009). The Singaporean English and Chinese versions of the EQ-5D achieved measurement equivalence in cancer patients. Journal of Clinical Epidemiol, 62(2), 206–213.
Herdman, M., Gudex, C., Lloyd, A., Janssen, M., Kind, P., Parkin, D., et al. (2011). Development and preliminary testing of the new five-level version of EQ-5D (EQ-5D-5L). Quality of Life Research, 20(10), 1727–1736.
Janssen, M. F., Busschbach, J., Golicki, D., et al. (2011). Proceedings of the 28th Plenary Meeting of the EuroQol Group. Oxford: Said Business School.
Wan, C., Zhang, D., Yang, Z., Tu, X., Tang, W., Feng, C., et al. (2007). Validation of the simplified Chinese version of the FACT-B for measuring quality of life for patients with breast cancer. Breast Cancer Research and Treatment, 106(3), 413–418.
Brady, M., Cella, D., Mo, F., Bonomi, A. E., Tulsky, D. S., Lloyd, S. R., et al. (1997). Reliability and validity of the functional assessment of cancer therapy—breast quality-of-life instrument. Journal of Clinical Oncology, 15(3), 974–986.
Cheung, Y. B., Goh, C., Thumboo, J., Khoo, K. S., & Wee, J. (2005). Variability and sample size requirements of quality-of-life measures: a randomized study of three major questionnaires. Journal of Clinical Oncology, 23(22), 4936–4944.
Lee, C. F., Ng, R., Luo, N., Wong, N. S., Yap, Y. S., Lo, S. K., et al. (2012). The English and Chinese versions of the 5-level EuroQoL Group’s 5-dimension questionnaire (EQ-5D) were valid and reliable and provided comparable scores in Asian breast cancer patients. Supportive Care Cancer,. doi:10.1007/s00520-012-1512-x.
Rabin R., Oemar M., Oppe M., Janssen B., Herdman M., EuroQoL Group Executive Office. (2011). EQ-5D-5L user guide: Basic information on how to use the EQ-5D-5L instrument. EuroQoL Group 2011. Avalable at http://www.euroqol.org/fileadmin/user_upload/Documenten/PDF/Folders_Flyers/UserGuide_EQ-5D-5L.pdf. Assessed 2 July, 2011.
Tsuchiya, A., Ikeda, S., Ikegami, N., Nishimura, S., Sakai, I., Fukuda, T., et al. (2002). Estimating an EQ-5D population value set: the case of Japan. Health Economics, 11(4), 341–353.
Ng, R., Lee, C. F., Wong, N. S., Luo, N., Yap, Y. S., Lo, S. K., et al. (2012). Measurement properties of the English and Chinese versions of the functional assessment of cancer therapy—breast (FACT-B) in Asian breast cancer patients. Breast Cancer Research and Treatment, 131(2), 619–625.
Senn, S. (2007). Statistical issues in drug development. Chichester: Wiley.
Barnett, A. G., van der Pols, J. C., & Dobson, A. J. (2005). Regression to the mean: what it is and how to deal with it. International Journal of Epidemiol, 34(1), 215–220.
Cheung, Y. B., Thumboo, J., Goh, C., Khoo, K. S., Che, W., & Wee, J. (2004). The equivalence and difference between the English and Chinese versions of two major cancer-specific health-related quality of life questionnaires. Cancer, 101(12), 2874–2880.
Efron B., Tibshirani R. (1993). An Introduction to the Bootstrap. New York, NY, Chapman & Hall.
Cuzick, J. (1985). A Wilcoxon-type test for trend. Statistics in Medicine, 4(1), 87–90.
Fayers, P. M., & Machin, D. (2000). Quality of life: assessment. Chichester: Analysis and Interpretation.
Acknowledgments
This research was supported by the Singapore Ministry of Health’s National Medical Research Council under its Exploratory/Developmental Grant and Clinician-Scientist Award.
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Lee, C.F., Luo, N., Ng, R. et al. Comparison of the measurement properties between a short and generic instrument, the 5-level EuroQoL Group’s 5-dimension (EQ-5D-5L) questionnaire, and a longer and disease-specific instrument, the Functional Assessment of Cancer Therapy—Breast (FACT-B), in Asian breast cancer patients. Qual Life Res 22, 1745–1751 (2013). https://doi.org/10.1007/s11136-012-0291-7
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DOI: https://doi.org/10.1007/s11136-012-0291-7