Linking Health-Related Quality-of-Life Indicators to Large National Data Sets
Objective: This study investigated the feasibility and usefulness of linking algorithms for well known quality-of-life (QOL) indicators to large nationally representative databases.
Design and Setting: The National Medical Expenditure Survey (NMES) was utilised. We developed an algorithm to match the EuroQOL health indicator and drew on a previous match of the Health Utilities Index (HUI) in a companion paper. This process allowed the sensitivity and detail of health-related quality-of-life (HR-QOL) indicators to be combined with the benefits of large, nationally representative data sets.
Patients and participants: A total of 19 525 individuals aged 18 years and older (constituting a nationally representative sample of the non-institutionalised civilian population of the US contained within the 1987 NMES database) were investigated.
Interventions: Sensitivity analyses using several related specifications of each indicator were performed. We analysed the correlations of these alternatives for both the HUI and EuroQOL measures. Correlations between the HUI and EuroQOL measures were also examined. We investigated the construct validity by examining the performance of the HUI and EuroQOLs in empirical situations in which we had knowledge about the relationships (e.g. health decreases with age).
Main outcome measures and results: The benefits of HR-QOL measures can be achieved relatively cheaply and efficiently via linking rather than developing a large scale QOL survey. Although the NMES data allowed a good match with the EuroQOL and the HUI, the matches were not perfect. By examining the within-domain correlations and the between-domain correlations, we found that the alternate specifications within-domain were very similar and that the 2 HRQOL indicators were comparable in many (but not all) aspects.
Conclusions: The results of this study suggested good construct validity. Thus, linked HR-QOL measures of the types derived in this study may be useful in characterising the health of large populations, and in investigating the causes and consequences of health.
KeywordsAdis International Limited Ordinary Little Square Health Utility Index Linkage Algorithm National Medical Expenditure Survey
Unable to display preview. Download preview PDF.
- 1.Berthelot J-M, Roberge R, Wolfson M. The calculation of health-adjusted life expectancy for a Canadian province using a multi-attribute utility function: a first attempt. In: Robine JM, Mathers CD, Bone MR, et al., editors. Calculation of health expectancies: harmonization, consensus achieved and future perspectives. Montrouge, France: Colloque INSERM/John Libbey Eurotext Ltd., 1993; 226: 161–72Google Scholar
- 2.Schipper H, Clinch JJ, Olweny CL. Quality of life studies: definitions and conceptual issues. In: Spilker B, editor. Quality of life and pharmacoeconomics in clinical trials. Philadelphia (PA): Lipincott-Raven Publishers, 1996: 11–23Google Scholar
- 3.Wolfson MC. Health-adjusted life expectancy. Health Rep 1996; 6 (1): 41–6Google Scholar
- 4.Erickson P. Modelling health-related quality of life: the bridge between psychometric and utility-based measures. J Natl Cancer Inst 1996; 20: 17–22Google Scholar
- 9.Curtis L. Socioeconomic status and health [thesis]. West Hamilton (ON): Department of Economics, McMaster University, 1998Google Scholar
- 10.Dolan P, Gudex C, Kind P, et al. A social tariff for EuroQol: results from a UK general population survey. York: Centre for Health Economics, University of York, 1995. Discussion paper no.: 138Google Scholar
- 14.Keeney RL, Raiffa H. Decisions with multiple objectives: preferences and value tradeoffs. New York: Cambridge University Press, 1993Google Scholar
- 17.Feeny DH, Torrance GW, Furlong WJ. Health utilities index. In: Spilker B, editor. Quality of life and pharmacoeconomics in clinical trials. 2nd ed. Philadelphia (PA): Lippincott-Raven Press, 1996: 239–52Google Scholar
- 18.Drummond MF, O’Brien B, Stoddart GL, et al. Methods for the economic evaluation of health care programmes. 2nd ed. Oxford: Oxford University Press, 1997Google Scholar
- 19.Drummond MF, Stoddart GL, Torrance GW. Methods for the economic evaluations of health care programmes. Oxford: Oxford University Press, 1987Google Scholar