Development and validation of a preference based measure derived from the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) for use in cost utility analyses

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Abstract

Background:
Pulmonary Hypertension is a severe and incurable disease with poor prognosis. A suite of new disease-specific measures ├óÔé¼ÔÇ£ the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) ├óÔé¼ÔÇ£ was recently developed for use in this condition. The purpose of this study was to develop and validate a preference ased measure from the CAMPHOR that could be used in cost-utility analyses.

Methods:
Items were selected that covered major issues covered by the CAMPHOR QoL scale (activities, travelling, dependence and communication). These were used to create 36 health states that were valued by 249 people representative of the UK adult population, using the time trade-off (TTO) technique. Data from the TTO interviews were analysed using both aggregate and individual level modelling. Finally, the original CAMPHOR validation data were used to validate the new preference based model.

Results:
The predicted health state values ranged rom 0.962 to 0.136. The mean level model selected for analyzing the data had good explanatory power (0.936), did not systematically over- or underestimate the observed ean health state values and showed no evidence of auto correlation in the prediction errors. The value of less than 1 reflects a background level of ill health in state 1111, as udged by the respondents. Scores derived from the new measure had excellent test-retest reliability (0.85) and construct validity. The CAMPHOR utility score appears better ble to distinguish between WHO functional classes (II and III) than the EQ- 5D and SF-6D.

Conclusions:
The tariff derived in this study can be sed o classify an individual into a health state based on their responses to the CAMPHOR. The results of this study widen the evidence base for conducting economic evaluations of nterventions designed to improve QoL for patients with PH.

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References
  1. Rubin LJ. Primary pulmonary hypertension. N Engl J Med 1997; 336: 111-7.
  2. Gibbs JSR, Higgenbottam TW. Recommendations on the management of pulmonary hypertension in clinical practice. Heart 2001; 86 (Suppl): i1-i13.
  3. Galie N, Manes A, Branzi A. Prostanoids for pulmonary arterial hypertension. Am J Respir ed. 2003; 2(2): 123-37.
  4. Scottish Medicines Consortium 2005. Review of Iloprost, November (219/05).
  5. Canadian Agency for Drugs and Technologies in ealth. Common drug review submission guidelines for Manufacturers 2007. Ottowa Canada. [http://cadth.ca/media/cdr/process/cdr_submission_Guidelines_2007-Oct1_e....
  6. Australian Government Department of Health and Ageing [http://health.gov.au/internet/wcms/publishing.nsf/Content/pbacguidelines... pbacguidelines-part2]
  7. National Institute for Clinical Excellence (NICE) (2004). Guide to the Methods of Technology Appraisal. National Health Service, London. 1-54.
  8. Brooks R, Rabin R, De Charro F. The Measurement and Valuation of Health status Using EQ-5D: A European Perspective. London: Kluwer Academic publishers, 2004.
  9. Brazier J, Roberts J, Deverill M. The estimation of a preference based single index measure for health from the SF-36. J Health Econ 2002; 21: 271-92.
  10. Feeny DH, Furlong WJ, Torrance GW, Goldsmith CH, Zhu Z, DePauw S, Denton M, Boyle l. Multiattribute and single attribute utility function ├óÔé¼ÔÇ£ the health utility index mark 3 system. Med Care 2002; 40: 113-28.
  11. Brazier JE, Severill M, Harper R, Booth A. A review of the use of health status measures in economic evaluation. Health Technology and Assessment 3 (9), 1999.
  12. Guyatt GH, King DR, Feeny DH, Stubbing D, oldstein RS. Generic and specific measurement of health-related quality of life in a clinical trial of respiratory rehabilitation. J Clin Epidemiol. 1999 Mar;52(3):187-92.
  13. McTaggart-Cowan HM, Marra CA, Yang Y, Brazier JE, Kopec JA, Fitzgerald JM, Anis AH, Lynd LD. The validity of generic and condition-specific preferencebased instruments: the ability to discriminate asthma control status. Qual Life Res. 2008 Apr;17(3):453-62.
  14. Krahn M, Bremner KE, Tomlinson G, Ritvo P, Irvine J, Naglie . responsiveness of disease-specific and generic utility instruments in prostate cancer patients. Qual Life Res. 2007 Apr;16(3):509-22.
  15. McKenna SP, Doughty N, Meads DM, oward LC, Pepke-Zaba J. The Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR): A measure of healthrelated quality of life and quality of life for patients with ulmonary hypertension. Qual Life Res 2006; 15: 103-15.
  16. Rasch, G. On general laws and the meaning of measurement in psychology. In J. Neyman (Ed). Proceedings of he Fourth Berkeley Symposium on Mathematical Statistics and Probability. IV, 321-334, Berkeley CA: University of California Press, 1961.
  17. Brazier JE, Czoski-Murray C, oberts J, Brown M, Symonds T, Kelleher C. Estimation of a preference-based index from a condition specific measure: the King™s Health Questionnaire. Med Decis aking, 2008; 28: 113 - 126.
  18. MVH Group. The measurement and valuation of health: Final report on the modelling of valuation tariffs. Centre for Health Economics, niversity of York, 1995.
  19. Dolan P. Modeling valuations for EuroQoL health states. Medical Care, 1997; 35(11):1095-1108.
  20. Keogh AM, McNeil KD, Wlodarczyk J, abbay E, Williams TJ. Quality of life in pulmonary arterial hypertension: improvement and maintenance with bosentan. J Heart Lung Transplant. 2007 Feb;26(2):181-7.
  21. owie J. Decision validity should determine whether a generic or condition specific HRQOL measure is used in health care decisions. Health Econ 2002; 11: 1-8.
  22. . Stolk EA, usschbach JJV. Validity and feasibility of the use of condition specific utcome measures in economic evaluation. Qual Life Res 2003; 12: 363-71.
  23. Revicki DA, Leidy NK, rennan-Diemer F, Sorensen S, Togias A. Integrating patients preferences into health outcomes assessment: the multiattribute asthma symptom utility index. Chest 1998; 14: 98-1007.
  24. Claxton K, Ginnelly L, Sculpher M, Philips Z, Palmer S. A pilot study on the use of decision theory and value of information analysis as part of the NHS Health Technology Assessment programme. Health Technol Assess. 2004 Jul;8(31):1-103, iii.
  25. Brazier J, Tsuchiya A, Busschbach J, Stolk E. Issues in estimating a preference ased index for condition specific measures. Presentation at the International Health Economics Association meeting, San Francisco, USA, 2002.
  26. Insinga RP, Fryback DG Understanding differences between self-ratings and population ratings for health in the EuroQOL. Qual Life Res. 2003 Sep;12(6):611-9.
  27. Brazier J, Roberts J, Deverill M. he estimation of a preference-based measure of health from the SF-36. J Health Econ. 2002 Mar;21(2):271-92.