IDEAS home Printed from https://ideas.repec.org/a/wly/hlthec/v8y1999i3p203-211.html
   My bibliography  Save this article

Sample size and power issues in estimating incremental cost‐effectiveness ratios from clinical trials data

Author

Listed:
  • Andrew R. Willan
  • Bernie J. O'Brien

Abstract

It is becoming increasingly more common for a randomized controlled trial of a new therapy to include a prospective economic evaluation. The advantage of such trial‐based cost‐effectiveness is that conventional principles of statistical inference can be used to quantify uncertainty in the estimate of the incremental cost‐effectiveness ratio (ICER). Numerous articles in the recent literature have outlined and compared various approaches for determining confidence intervals for the ICER. In this paper we address the issue of power and sample size in trial‐based cost‐effectiveness analysis. Our approach is to determine the required sample size to ensure that the resulting confidence interval is narrow enough to distinguish between two regions in the cost‐effectiveness plane: one in which the new therapy is considered to be cost‐effective and one in which it is not. As a result, for a given sample size, the cost‐effectiveness plane is divided into two regions, separated by an ellipse centred at the origin, such that the sample size is adequate only if the truth lies on or outside the ellipse. Copyright © 1999 John Wiley & Sons, Ltd.

Suggested Citation

  • Andrew R. Willan & Bernie J. O'Brien, 1999. "Sample size and power issues in estimating incremental cost‐effectiveness ratios from clinical trials data," Health Economics, John Wiley & Sons, Ltd., vol. 8(3), pages 203-211, May.
    • Handle: RePEc:wly:hlthec:v:8:y:1999:i:3:p:203-211
    DOI: 10.1002/(SICI)1099-1050(199905)8:3<203::AID-HEC413>3.0.CO;2-7
    as

    Download full text from publisher

    File URL: https://doi.org/10.1002/(SICI)1099-1050(199905)8:33.0.CO;2-7
    Download Restriction: no
    File URL: https://libkey.io/10.1002/(SICI)1099-1050(199905)8:3<203::AID-HEC413>3.0.CO;2-7?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    References listed on IDEAS

    as
    1. Andrew Briggs & Mark Sculpher & Martin Buxton, 1994. "Uncertainty in the economic evaluation of health care technologies: The role of sensitivity analysis," Health Economics, John Wiley & Sons, Ltd., vol. 3(2), pages 95-104, March.
    2. Daniel Polsky & Henry A. Glick & Richard Willke & Kevin Schulman, 1997. "Confidence Intervals for Cost–Effectiveness Ratios: A Comparison of Four Methods," Health Economics, John Wiley & Sons, Ltd., vol. 6(3), pages 243-252, May.
    3. Bernie O'Brien & Amiram Gafni, 1996. "When Do the "Dollars" Make Sense?," Medical Decision Making, , vol. 16(3), pages 288-299, August.
    4. Andrew H. Briggs & David E. Wonderling & Christopher Z. Mooney, 1997. "Pulling cost‐effectiveness analysis up by its bootstraps: A non‐parametric approach to confidence interval estimation," Health Economics, John Wiley & Sons, Ltd., vol. 6(4), pages 327-340, July.
    5. Alan Diener & Bernie O'Brien & Amiram Gafni, 1998. "Health care contingent valuation studies: a review and classification of the literature," Health Economics, John Wiley & Sons, Ltd., vol. 7(4), pages 313-326, June.
    6. Andrew H. Briggs & Alastair M. Gray, 1998. "Power and Sample Size Calculations for Stochastic Cost-Effectiveness Analysis," Medical Decision Making, , vol. 18(2_suppl), pages 81-92, April.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Michaël Schwarzinger & Jean‐Louis Lanoë & Erik Nord & Isabelle Durand‐Zaleski, 2004. "Lack of multiplicative transitivity in person trade‐off responses," Health Economics, John Wiley & Sons, Ltd., vol. 13(2), pages 171-181, February.
    2. Joseph C. Gardiner & Marianne Huebner & James Jetton & Cathy J. Bradley, 2000. "Power and sample assessments for tests of hypotheses on cost‐effectiveness ratios," Health Economics, John Wiley & Sons, Ltd., vol. 9(3), pages 227-234, April.
    3. Walters, SJ & Brazier, JE, 2002. "Sample sizes for the SF-6D preference based measure of health from the SF-36: a practical guide," MPRA Paper 29742, University Library of Munich, Germany.
    4. Andrew Willan, 2011. "Sample Size Determination for Cost-Effectiveness Trials," PharmacoEconomics, Springer, vol. 29(11), pages 933-949, November.
    5. Henry Glick, 2011. "Sample Size and Power for Cost-Effectiveness Analysis (Part 1)," PharmacoEconomics, Springer, vol. 29(3), pages 189-198, March.
    6. Martin W. McIntosh & Scott D. Ramsey & Kristin Berry & Nicole Urban, 2001. "Parameter solicitation for planning cost effectiveness studies with dichotomous outcomes," Health Economics, John Wiley & Sons, Ltd., vol. 10(1), pages 53-66, January.
    7. A. Gafni & S. D. Walter & S. Birch & P. Sendi, 2008. "An opportunity cost approach to sample size calculation in cost‐effectiveness analysis," Health Economics, John Wiley & Sons, Ltd., vol. 17(1), pages 99-107, January.
    8. Gafni, Amiram & Birch, Stephen, 2006. "Incremental cost-effectiveness ratios (ICERs): The silence of the lambda," Social Science & Medicine, Elsevier, vol. 62(9), pages 2091-2100, May.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Kobelt, G., 2013. "Health Economics: An Introduction to Economic Evaluation," Monographs, Office of Health Economics, number 000004.
    2. Laura J. Damschroder & Peter A. Ubel & Jason Riis & Dylan M. Smith, 2007. "An alternative approach for eliciting willingness-to-pay: A randomized Internet trial," Judgment and Decision Making, Society for Judgment and Decision Making, vol. 2, pages 96-106, April.
    3. Daniel F. Heitjan & Alan J. Moskowitz & William Whang, 1999. "Bayesian estimation of cost‐effectiveness ratios from clinical trials," Health Economics, John Wiley & Sons, Ltd., vol. 8(3), pages 191-201, May.
    4. Halkos, George, 2012. "The use of contingent valuation in assessing marine and coastal ecosystems’ water quality: A review," MPRA Paper 42183, University Library of Munich, Germany.
    5. Wim Groot & Henriëtte Maassen van den Brink & Erik Plug, 2004. "Money for health: the equivalent variation of cardiovascular diseases," Health Economics, John Wiley & Sons, Ltd., vol. 13(9), pages 859-872, September.
    6. Martin W. McIntosh & Scott D. Ramsey & Kristin Berry & Nicole Urban, 2001. "Parameter solicitation for planning cost effectiveness studies with dichotomous outcomes," Health Economics, John Wiley & Sons, Ltd., vol. 10(1), pages 53-66, January.
    7. Andrew R. Willan & Andrew H. Briggs & Jeffrey S. Hoch, 2004. "Regression methods for covariate adjustment and subgroup analysis for non‐censored cost‐effectiveness data," Health Economics, John Wiley & Sons, Ltd., vol. 13(5), pages 461-475, May.
    8. Stéphane Luchini & Christel Protière & Jean‐Paul Moatti, 2003. "Eliciting several willingness to pay in a single contingent valuation survey: application to health care," Health Economics, John Wiley & Sons, Ltd., vol. 12(1), pages 51-64, January.
    9. Demissie Alemayehu, 2014. "Methodological Considerations in Cost-Effectiveness Analysis," Proceedings of Economics and Finance Conferences 0401651, International Institute of Social and Economic Sciences.
    10. Stephen Palmer & Peter Smith, 1999. "Incorporating option values into the economic evaluation of health care technologies," Working Papers 166chedp, Centre for Health Economics, University of York.
    11. Tommi Härkänen & Timo Maljanen & Olavi Lindfors & Esa Virtala & Paul Knekt, 2013. "Confounding and missing data in cost-effectiveness analysis: comparing different methods," Health Economics Review, Springer, vol. 3(1), pages 1-11, December.
    12. Eulàlia Dalmau‐Matarrodona, 2001. "Alternative approaches to obtain optimal bid values in contingent valuation studies and to model protest zeros. Estimating the determinants of individuals' willingness to pay for home care services in," Health Economics, John Wiley & Sons, Ltd., vol. 10(2), pages 101-118, March.
    13. Joseph C. Gardiner & Marianne Huebner & James Jetton & Cathy J. Bradley, 2000. "Power and sample assessments for tests of hypotheses on cost‐effectiveness ratios," Health Economics, John Wiley & Sons, Ltd., vol. 9(3), pages 227-234, April.
    14. Raphaël Remonnay & Nathalie Havet & Magali Morelle & Marie-Odile Carrère, 2008. "Analyzing the determinants of willingness-to-pay values for testing the validity of the contingent valuation method. Application to home care compared to hospital care," Working Papers 0820, Groupe d'Analyse et de Théorie Economique Lyon St-Étienne (GATE Lyon St-Étienne), Université de Lyon.
    15. Garming, Hildegard & Waibel, Hermann, 2006. "Willingness To Pay To Avoid Health Risks From Pesticides, A Case Study From Nicaragua," 46th Annual Conference, Giessen, Germany, October 4-6, 2006 14968, German Association of Agricultural Economists (GEWISOLA).
    16. Andrew Briggs & Paul Fenn, 1998. "Confidence intervals or surfaces? Uncertainty on the cost‐effectiveness plane," Health Economics, John Wiley & Sons, Ltd., vol. 7(8), pages 723-740, December.
    17. repec:cup:judgdm:v:2:y:2007:i::p:96-106 is not listed on IDEAS
    18. Phil Shackley & Cam Donaldson, 2000. "Willingness to pay for publicly-financed health care: how should we use the numbers?," Applied Economics, Taylor & Francis Journals, vol. 32(15), pages 2015-2021.
    19. Nathalie Havet & Magali Morelle & Alexis Penot & Raphaël Remonnay, 2012. "The information content of the WTP-WTA gap : An empirical analysis among severely ill patients," Working Papers halshs-00697762, HAL.
    20. Daniel F. Heitjan & Huiling Li, 2004. "Bayesian estimation of cost‐effectiveness: an importance‐sampling approach," Health Economics, John Wiley & Sons, Ltd., vol. 13(2), pages 191-198, February.
    21. Joanne Lord & Maxwell A. Asante, 1999. "Estimating uncertainty ranges for costs by the bootstrap procedure combined with probabilistic sensitivity analysis," Health Economics, John Wiley & Sons, Ltd., vol. 8(4), pages 323-333, June.

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:wly:hlthec:v:8:y:1999:i:3:p:203-211. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Wiley Content Delivery (email available below). General contact details of provider: http://www3.interscience.wiley.com/cgi-bin/jhome/5749 .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.