Mapping the Shah-modified Barthel Index to the Health Utility Index Mark III by the Mean Rank Method
To map the Shah-modified Barthel Index (SBI) to the Health Utility Index Mark III (HUI-3) in stroke patients, and to compare the performance of a recently developed method called the Mean Rank Method (MRM) against a popular method, the Ordinary Least Squares (OLS) method.
A cohort of 473 patients who had their first clinical stroke diagnosis and hospital admission and were assessed using the SBI and HUI-3 at 3 months and/or 12 months post-admission. Observations were split to form a training dataset (N = 473) and a validation dataset (N = 245).
In the training dataset, the MRM using SBI total score as the predictor produced a mapped utility distribution that closely resembled the observed utility distribution. It had almost no shrinkage of the standard deviation (P = 0.542), whereas the OLS using SBI total score and SBI item scores under-estimated the standard deviation by 28% and 26%, respectively (each P < 0.001). The MRM mapping gave better fit in terms of smaller mean absolute error and larger intra-class correlation than the two versions of OLS mapping, whereas the OLS gave smaller mean-squared errors than the MRM. Multivariate regression analysis showed that the use of OLS-mapped utilities tended to under-estimate both the mean utility of people who had no comorbidity and the utility-comorbidity association as compared to the observed utility-comorbidity pattern although the differences did not reach statistical significance (each P > 0.05). The MRM-mapped utility showed utility-comorbidity pattern more similar to the observed. Similar findings were obtained from the validation dataset.
The MRM performed well. Mapping functions are available to map the SBI to the HUI-3 Utility Index.
KeywordsActivities of daily living Barthel Index Health utility Health Utility Index Mark III Mapping Stroke
Conceptualization: YBC, NL, and HLW and GCHK. Data analysis: YBC and HXT. Writing, original draft: YBC and HXT. Writing, critical review and final version: HXT, YBC, NL, and HLW, GCHK.
Compliance with ethical standards
Conflict of interest
All authors declare that they have no potential conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (National University of Singapore Institutional Review Board S17-257E) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
- 4.Drummond, M. F., Sculpher, M. J., Claxton, K., et al. (2015). Methods for the economic evaluation of health care programmes. Oxford: Oxford University Press.Google Scholar
- 6.Fayers, P. M., & Machin, D. (2016). Quality of life: The assessment, analysis and reporting of patient-reported outcomes (3rd ed.). Oxford: Wiley.Google Scholar
- 7.National Institue for Health and Care Excellence. (2013). Guide to the Methods of Technology Appraisal. London: National Institute for Health and Care Excellence.Google Scholar
- 9.Agency for Care Effectiveness. (2018). Drug Evaluation Methods and Process Guide. Singapore: Agency for Care Effectiveness, Ministry of Health.Google Scholar
- 10.Singapore Ministry of Health. (2016). ElderShield Fast Facts. Singapore: Ministry of Health.Google Scholar
- 17.Wee, H. L., Yeo, K. K., Chong, K. J., Khoo, E. Y. H., & Cheung, Y. B. (2018). Mean rank, equipercentile and regression mapping of World Health Organization Qualty of Life Brief (WHOQOL-BREF) to EuroQoL 5 Dimensions 5 Levels (EQ-5D-5L) utilties. Medical Decision Making,38(3), 319–333.CrossRefGoogle Scholar
- 20.Cheung, Y. B., Luo, N., Ng, R., & Lee, C. F. (2014). Mapping the Functional Assessment of Cancer Therapy—Breast (FACT-B) to the 5-level EuroQoL Group’s 5-dimension questionnaire (EQ-5D-5L) utility index in a Multi-ethnic Asian Population. Health and Quality of Life Outcomes,12, 180.CrossRefGoogle Scholar
- 27.Lee, C. F., Ng, R., Luo, N., & Cheung, Y. B. (2018). Development of conversion functions mapping the FACT-B total score to the EQ-5D-5L utility value by three linking methods and comparison with the ordinary least square method. Applied Health Economics and Health Policy,16(5), 685–695.CrossRefGoogle Scholar
- 32.Greene, W. H. (2012). Econometric Analysis (7th ed.). Upper Saddle River: Prentice Hall.Google Scholar
- 33.Singapore Stroke Registry, Ministry of Health. (2015). Trends in Stroke in Singapore 2005-2015. Singapore Storke Registry Report No. 4. Singapore: National Registry of Disease Office, Ministry of Health.Google Scholar