Abstract
This study estimated a model from which data routinely collected in clinical trials of angina patients can be mapped to a utility scale and used to estimate quality-adjusted life years (QALYs). Patients with stable angina attending four cardiac out-patient clinics in the UK were included in the study. Data collected included information on patients’ health-related quality of life (HRQL) using the EQ-5D, and severity of angina symptoms using two cardiac-specific measures [Breathlessness Grade and Canadian Cardiovascular Society (CCS) classification of angina]. Regression analysis was used to predict EQ-5D index values from the data. Data were obtained from 510 patients. For CCS grades, mean EQ-5D scores ranged from 0.36 (95% confidence interval 0.25–0.48) for grade 4 to 0.81 (0.77–0.85) for grade 0, and for breathlessness grades, EQ-5D scores ranged from 0.31 (0.06–0.55) for grade 0 to 0.84 (0.79–0.88) for grade 5. The final model used data on CCS grades, breathlessness grades, and patients’ current medications to predict EQ-5D scores. The model had an R2 value of 0.37, and predictions for less severe angina were considered more reliable than the estimates for severe angina. In the absence of utility data collected as part of a clinical trial it is possible to map HRQL utility data from samples of patients with similar characteristics to those in the original trial. The uncertainty surrounding the estimates should be considered when using the results to estimate QALYs for purposes of economic evaluation.
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References
Kind P (1996) The EuroQoL instrument: an index of health-related quality of life. In: Spilker B (1996) Quality of life and pharmacoeconomics in clinical trials. Lippincott-Raven, Philadelphia
Patrick DL, Erickson P (1993) Health status and health Policy. Allocating resources to health care. Oxford University Press, New York
Torrance GW, Feeny DH, Furlong WJ et al. (1996) Multiattribute utility function for a comprehensive health status classification system: Health Utilities Index Mark 2. Med Care 34:702–722
Brazier J, Roberts J, Deverill M (2002) The estimation of a preference-based measure of health from the SF-36. J Health Econ 21:271–292
Raftery J (2001) NICE: faster access to modern treatments? Analysis of guidance of health technologies. BMJ 323:1300–1303
National Institute for Clinical Excellence (2004) Guide to the methods of technology appraisals. Available at http://www.nice.org.uk; accessed 6 December 2004
Gold MR, Siegel JE, Russell LB et al. (1996) Cost-effectiveness in health and medicine. Oxford University Press: New York
Kinlay S (1996) Cost-effectiveness of coronary angioplasty versus medical treatment: the impact of cost-shifting. Aust N Z J Med 26:20–26
Mark D, Harrington RA, Lincoff MA et al. (2000) Cost-effectiveness of platelet glycoprotein Iib/IIIa inhibition with eptifibatide in patients with non-ST-elevation acute coronary syndromes. Circulation 101:366–371
Serruys PW, Unger F, Sousa JE et al. (2001) Comparison of coronary-artery bypass surgery and stenting for the treatment of multivessel disease. N Engl J Med 344:1117–1124
Meslop KA, Boothroyd DB, Hlatky M (2003) Quality of life and time trade-off utility measures in patients with coronary artery disease. Am Heart J 145:36–41
RITA-2 Trial Participants (1997) Coronary angioplasty versus medical therapy for angina: the second randomised intervention treatment of angina (RITA-2) trial. Lancet 350:461–468
Pocock SJ, Henderson RA, Clayton T et al. (2000) Quality of life after coronary angioplasty or continued medical treatment for angina: three year follow up in the RITA −2 trial. J Am Col Cardiol 34:907–914
Kirsch J, McGuire A (2000) establishing health state valuations for disease specific states: an example from heart disease. Health Econ 9:149–148
Martin AJ, Glasziou PP, Simes RJ et al. (1998) Predicting patients’ utilities from quality of life items: an improved scoring system for the UBQ-H. Qual Life Res 7:703–711
Nichol G, Llewellyn-Thomas HA, Theil EC et al. (1996) The relationship between cardiac functional capacity and patient’ symptom-specific utilities for angina. Med Decis Making 16:78–85
Campeau L (1976) Grading of angina pectoris. Circulation 54:522–523
Brooks R (1996) EQ-5D, the current state of play. Health Policy 37:53–72
Dolan P (1997) Modelling valuations for EuroQol health states. Med Care 35:1095–1108
Sculpher MJ, Seed P, Henderson RA et al. (1994) Health service costs of coronary angioplasty and coronary artery bypass surgery: the RITA trial. Lancet 344:927–930
Box GE, Cox D (1964) An analysis of transformations. J R Stat Soc Ser B 26:211–252
Dolan P, Gudex C, Kind P et al. (1996) The time trade-off method: results from a general population study. Health Econ 5:141–154
Briggs A, Clark T, Wolstenholme J et al. (2005) Missing...Presumed at random: cost-analysis of incomplete data. Health Econ 12:377–392
Nease RF Jr, Kneeland T, O’Connor GT et al. (1995) Variation in patient utilities for outcomes of the management of chronic stable angina. JAMA 273:1185–1190
Acknowledgements
We thank all of the patients who participated in this study. We acknowledge the RITA study team, particularly Tim Clayton, Rob Henderson, Rosemary Knight and Stuart Pocock. We also thank the research nurses and clinicians for their assistance in the data collection for this project: M. Marriott, K. Knowles, R. Henderson (Nottingham City Hospital); C. Davies, M. Preston, M. Rothman (London Chest Hospital); Sandra Brant, S. Lavender, C. Ilsley (Royal Brompton and Harefield Hospital); and A. MacDermott, D. Reid (Freeman Hospital, Newcastle). An earlier version of this study was presented at the Second ‘Developing Economic Evaluation Methods’ seminar at University of York, UK 2002. The authors thank Andrew Briggs and Tracey Young for helpful comments on the statistical analysis. Financial support for the project was received from the British Heart Foundation and the Department of Health as part of the ongoing RITA trials. The Health Economics Research Group receives funding from the Department of Health Policy Research Programme grant. M.S. is supported by a Career Scientist Award in Public Health funded by the NHS Research and Development Programme. L.L. is now employed by the National Institute for Health and Clinical Excellence, but the study was conducted whilst she was a researcher at Brunel University. The views expressed in this contribution and any errors or omissions are the responsibility of the authors.
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Longworth, L., Buxton, M.J., Sculpher, M. et al. Estimating utility data from clinical indicators for patients with stable angina. Eur J Health Econ 6, 347–353 (2005). https://doi.org/10.1007/s10198-005-0309-y
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DOI: https://doi.org/10.1007/s10198-005-0309-y