Model Structuring for Economic Evaluations of New Health Technologies
In countries such as Australia, the UK and Canada, decisions on whether to fund new health technologies are commonly informed by decision analytic models. While the impact of making inappropriate structural choices/assumptions on model predictions is well noted, there is a lack of clarity about the definition of key structural aspects, the process of developing model structure (including the development of conceptual models) and uncertainty associated with the structuring process (structural uncertainty) in guidelines developed by national funding bodies. This forms the focus of this article. Building on the reports of good modelling practice, and recognising the fundamental role of model structuring within the model development process, we specified key structural choices and provided ideas about model structuring for the future direction. This will help to further standardise guidelines developed by national funding bodies, with potential impact on transparency, comprehensiveness and consistency of model structuring. We argue that the process of model structuring and structural sensitivity analysis should be documented in a more systematic and transparent way in submissions to national funding bodies. Within the decision-making process, the development of conceptual models and presentation of all key structural choices would mean that national funding bodies could be more confident of maximising value for money when making public funding decisions.
Compliance with Ethical Standards
HHAA conceptualised and drafted the manuscript, and all co-authors reviewed and suggested changes. All authors reviewed and approved the final draft.
The Alan Williams Fellowship Award (Centre for Health Economics, the University of York) received by Hossein Haji Ali Afzali contributed to the conceptualisation of this article. This study was also supported by the National Health and Medical Research Council (NHMRC) of Australia via funding provided for the Centre of Research Excellence in Frailty and Healthy Ageing.
Conflict of Interest
Hossein Haji Ali Afzali is a member of the Evaluation Sub-Committee of the Medical Services Advisory Committee and Jonathan Karnon is a member of the Economic Sub-Committee of the Pharmaceutical Benefits Advisory Committee. Laura Bojke has no conflicts of interest to declare.
- 4.Drummond MF, Sculpher MJ, Claxton K, et al. Methods for the economic evaluation of health care programmes. 4th ed. Oxford: Oxford University Press; 2015.Google Scholar
- 6.Tappenden P. Conceptual modelling for health economic model development. HEDS Discussion Paper 12/05. 2012. http://eprints.whiterose.ac.uk/74464/1/HEDSDP1205.pdf. Accessed 1 Dec 2015.
- 8.Andronis L, Barton P, Bryan S. Sensitivity analysis in economic evaluation: an audit of NICE current practice and a review of its use and value in decision-making. Health Technol Assess. 2009;13:iii, ix–xi, 1–61.Google Scholar
- 10.Draper D. Assessment and propagation of model uncertainty. J R Stat Soc Series B Stat Methodol. 1995;57:45–97.Google Scholar
- 14.Frederix GWJ, van Hasselt JGC, Schellens JHM, Hovels A, Raaijmakers JAM, Huitema ADR, et al. The impact of structural uncertainty on cost-effectiveness models for adjuvant endocrine breast cancer treatments: the need for disease-specific model standardization and improved guidance. Pharmacoeconomics. 2014;32:47–61.CrossRefPubMedGoogle Scholar
- 20.Kaltenthaler E, Tappenden P, Paisley S, Squires H. Identifying and reviewing evidence to inform the conceptualisation and population of cost-effectiveness models. NICE DSU Technical Support Document 13. Sheffield: School of Health and Related Research, University of Sheffield; 2011 [December 2015]. http://www.nicedsu.org.uk. Accessed 9 May 2018.
- 21.Claxton K, Palmer S, Longworth L, Bojke L, Griffin S, McKenna C, et al. Informing a decision framework for when NICE should recommend the use of health technologies only in the context of an appropriately designed programme of evidence development. Health Technol Assess. 2012;16:1–323.CrossRefPubMedGoogle Scholar
- 24.Briggs AH, Claxton K, Sculpher MJ. Decision modelling for health economic evaluation. Oxford: Oxford University Press; 2006.Google Scholar
- 25.Gray AM, Clarke PM, Wolstenholme JL, et al. Applied methods of cost effectiveness analysis in health care. New York: Oxford University Press; 2011.Google Scholar
- 26.Gold MR. Cost-effectiveness in health and medicine. New York: Oxford University Press; 1996.Google Scholar
- 28.Kaltenthaler E, Tappenden P, Paisley S, Squires H. NICE DSU Technical Support Document 13: identifying and reviewing evidence to inform the conceptualisation and population of cost-effectiveness models. NICE Decision Support Unit Technical Support Documents. London: NICE; 2011.Google Scholar
- 37.Wooldridge JM. Econometric analysis of cross section and panel data. 2nd ed. Cambridge (MA): MIT Press; 2010.Google Scholar
- 47.National Institute for Health and Care Excellence (NICE). Single technology appraisal: user guide for company evidence submission template. UK; 2015. https://www.nice.org.uk/process/pmg24/chapter/cost-effectiveness. Accessed 10 Apr 2018.
- 48.CADTH. Guidelines for the economic evaluation of health technologies: Canada 2017. https://www.cadth.ca/dv/guidelines-economic-evaluation-health-technologies-canada-4th-edition. Accessed 10 Apr 2018.
- 49.Pharmaceutical Benefits Advisory Committee (PBAC). Guidelines for preparing a submission to the Pharmaceutical Benefits Advisory Committee 2016. https://pbac.pbs.gov.au/information/printable-version-of-guidelines.html. Accessed 10 Apr 2018.
- 50.Haute Autorité de Santé (HAS). Choices in methods for economic evaluation. Saint-Denis La Plaine: Department of Economics and Public Health Assessment (HAS); 2012.Google Scholar
- 51.Latimer N. Survival analysis for economic evaluations alongside clinical trials—extrapolation with patient-level data. NICE DSU Technical Support Document 14. Sheffield: School of Health and Related Research, University of Sheffield; 2013 [December 2015]. http://www.nicedsu.org.uk. Accessed 9 May 2018.CrossRefPubMedGoogle Scholar