Mapping of the EQ-5D index from clinical outcome measures and demographic variables in patients with coronary heart disease

BackgroundThe EuroQoL 5D (EQ-5D) is a questionnaire that provides a measure of utility for cost-effectiveness analysis. The EQ-5D has been widely used in many patient groups, including those with coronary heart disease. Studies often require patients to complete many questionnaires and the EQ-5D may not be gathered. This study aimed to assess whether demographic and clinical outcome variables, including scores from a disease specific measure, the Seattle Angina Questionnaire (SAQ), could be used to predict, or map, the EQ-5D index value where it is not available.MethodsPatient-level data from 5 studies of cardiac interventions were used. The data were split into two groups - approximately 60% of the data were used as an estimation dataset for building models, and 40% were used as a validation dataset. Forward ordinary least squares linear regression methods and measures of prediction error were used to build a model to map to the EQ-5D index. Age, sex, a proxy measure of disease stage, Canadian Cardiovascular Society (CCS) angina severity class, treadmill exercise time (ETT) and scales of the SAQ were examined.ResultsThe exertional capacity (ECS), disease perception (DPS) and anginal frequency scales (AFS) of the SAQ were the strongest predictors of the EQ-5D index and gave the smallest root mean square errors. A final model was chosen with age, gender, disease stage and the ECS, DPS and AFS scales of the SAQ. ETT and CCS did not improve prediction in the presence of the SAQ scales. Bland-Altman agreement between predicted and observed EQ-5D index values was reasonable for values greater than 0.4, but below this level predicted values were higher than observed. The 95% limits of agreement were wide (-0.34, 0.33).ConclusionsMapping of the EQ-5D index in cardiac patients from demographics and commonly measured cardiac outcome variables is possible; however, prediction for values of the EQ-5D index below 0.4 was not accurate. The newly designed 5-level version of the EQ-5D with its increased ability to discriminate health states may improve prediction of EQ-5D index values.

[1]  pectoris: prospective observational study decisions on alternative treatments for angina Cost effectiveness of clinically appropriate , 2007 .

[2]  R. Rabin,et al.  EQ-SD: a measure of health status from the EuroQol Group , 2001, Annals of medicine.

[3]  G. Bonsel,et al.  Comparing the standard EQ-5D three-level system with a five-level version. , 2008, Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research.

[4]  John Brazier,et al.  A review of the use of health status measures in economic evaluation. , 1999, Health technology assessment.

[5]  L. Sharples,et al.  Cost-effectiveness of functional cardiac testing in the diagnosis and management of coronary artery disease: a randomised controlled trial. The CECaT trial. , 2007, Health technology assessment.

[6]  L. Sharples,et al.  Cost-effectiveness of ventricular assist device use in the United Kingdom: results from the evaluation of ventricular assist device programme in the UK (EVAD-UK). , 2006, The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation.

[7]  P. Dolan,et al.  Modeling valuations for EuroQol health states. , 1997, Medical care.

[8]  L. Sharples,et al.  Trial-based cost-utility comparison of percutaneous myocardial laser revascularisation and continued medical therapy for treatment of refractory angina pectoris , 2005, The European Journal of Health Economics.

[9]  K. Eagle,et al.  Validation of the EQ‐5D in patients with a history of acute coronary syndrome* , 2005, Current medical research and opinion.

[10]  R. Tio,et al.  An open label, single-centre, randomized trial of spinal cord stimulation vs. percutaneous myocardial laser revascularization in patients with refractory angina pectoris: the SPiRiT trial: reply , 2006 .

[11]  Paul Kind,et al.  UK population norms for EQ-5D , 1999 .

[12]  P. Dolan,et al.  The time trade-off method: results from a general population study. , 1996, Health economics.

[13]  H Hemingway,et al.  Cost effectiveness of clinically appropriate decisions on alternative treatments for angina pectoris: prospective observational study , 2007, BMJ : British Medical Journal.

[14]  A. Kasuya.  EuroQol--a new facility for the measurement of health-related quality of life. , 1990, Health policy.

[15]  R. Bruce,et al.  Stress testing in screening for cardiovascular disease. , 1969, Bulletin of the New York Academy of Medicine.

[16]  Oliver Rivero-Arias,et al.  Estimating the Association between SF-12 Responses and EQ-5D Utility Values by Response Mapping , 2006, Medical decision making : an international journal of the Society for Medical Decision Making.

[17]  H. Hahmann,et al.  Validation of the EuroQol questionnaire in cardiac rehabilitation , 2005, Heart.

[18]  L. Sharples,et al.  A UK trial-based cost--utility analysis of transmyocardial laser revascularization compared to continued medical therapy for treatment of refractory angina pectoris. , 2001, European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery.

[19]  A. Williams.  EuroQol : a new facility for the measurement of health-related quality of life , 1990 .

[20]  J. Brazier,et al.  Deriving preference-based single indices from non-preference based condition-specific instruments: converting AQLQ into EQ5D indices , 2002 .

[21]  John E. Brazier,et al.  Comparison of the minimally important difference for two health state utility measures: EQ-5D and SF-6D , 2005, Quality of Life Research.

[22]  L. Lindamer.  Measuring Health: A Guide to Rating Scales and Questionnaires, 2nd Edition , 1998 .

[23]  I. McDowell,et al.  Measuring health: A guide to rating scales and questionnaires, 3rd ed. , 2006 .

[24]  Martin J Buxton,et al.  A review of health utilities using the EQ-5D in studies of cardiovascular disease , 2010, Health and quality of life outcomes.

[25]  I. Mcdowell.  General Health Status and Quality of Life , 2006 .

[26]  A Simon Pickard,et al.  Psychometric Comparison of the Standard EQ-5D to a 5 Level Version in Cancer Patients , 2007, Medical care.

[27]  Mark Sculpher,et al.  Estimating utility data from clinical indicators for patients with stable angina , 2005, The European Journal of Health Economics.

[28]  L. Sharples,et al.  The influence of demographic factors and health-related quality of life on treatment satisfaction in patients with gastroesophageal reflux disease treated with esomeprazole , 2005, Health and quality of life outcomes.

[29]  Aki Tsuchiya,et al.  A review of studies mapping (or cross walking) non-preference based measures of health to generic preference-based measures , 2010, The European Journal of Health Economics.