Abstract
A comorbidity is defined as the presence of at least one additional health condition co-occurring with a primary health condition. Decision analytic models in healthcare depict the typical clinical pathway of patients in general clinical practice and frequently include health states defined to represent comorbidities such as sequelae or adverse events. Health state utility values (HSUVs) are often not available for these and analysts generally estimate them. This article provides a summary of the methodological literature on estimating methods frequently used together with worked examples. The three main methods used (minimum, multiplicative and additive) can produce a wide range in the values estimated. In general, the minimum method overestimates observed HSUVs and the magnitude of error tends to increase as the observed values decrease. Conversely, the additive and multiplicative methods generally underestimate observed values and the magnitude of the errors is generally greater for the additive method. HSUVs estimated using the multiplicative method tend to decrease for lower HSUVs and the largest errors are in observed HSUVs >0.6. Differences in estimated values can produce substantial differences in the resulting incremental cost effectiveness ratio. Based on the current evidence, the multiplicative method is advocated but additional research is required to determine appropriate methods when estimating values for additional comorbidities.
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References
Fu AZ, Kattan MW. Utilities should not be multiplied: evidence from the preference-based scores in the United States. Med Care. 2008;46(9):984–90.
Hu B, Fu AZ. Predicting utility for joint health states: a general framework and a new nonparametric estimator. Med Decis Mak. 2010;30(5):E29–39.
Ara R, Brazier J. Comparing EQ-5D scores for comorbid health conditions estimated using five different methods. Med Care. 2012;50(5):452–9.
Ara R, Brazier J. Estimating health state utility values for comorbid health conditions using SF-6D data. Value Health. 2011;14(7):740–5.
Janssen M, Bonsel G. Estimating preference weights for chronic multimorbidity: don’t add, multiply. In: Proceedings of the EuroQol Group 2008. http://www.euroqol.org/uploads/media/CH02-Janssen.pdf. Accessed 11 Sept 2016.
Flanagan W, McIntosh CN, Le Petit C, Berthelot JM. Deriving utility scores for co-morbid conditions: a test of the multiplicative model for combining individual condition scores. Popul Health Metr. 2006;4:13. doi:10.1186/1478-7954-4-13.
Ara R, Brazier JE. Populating an economic model with health state utility values: moving toward better practice. Value Health. 2010;13(5):509–18.
Ara R, Wailoo AJ. Estimating health state utility values for joint health conditions: a conceptual review and critique of the current evidence. Med Decis Mak. 2013;33(2):139–53.
Ara R, Wailoo A. NICE DSU Technical Support Document 12: the use of health state utility values in decision models. National Health Service, 2011. http://www.nicedsu.org.uk. Accessed 11 Sept 2016.
Acknowledgements
The authors would like to thank Prof. Jon Karnon, PhD, of The University of Adelaide and Dr Andrew Lloyd, PhD, of Bladen Associates Ltd for their editorial review.
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RA reviewed the literature, wrote the first draft of the manuscript and made edits on the final draft. JEB made significant edits to the first and final draft of the manuscript. IAZ made significant edits to the first and final draft of the manuscript.
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This article is published in a special edition journal supplement wholly funded by Takeda Pharmaceutical International AG, Zurich, Switzerland.
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This study was funded by an unrestricted grant from Takeda Pharmaceuticals International AG.
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Roberta Ara has no conflicts of interest. John Brazier has no conflicts of interest.
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Ara, R., Brazier, J. Estimating Health State Utility Values for Comorbidities. PharmacoEconomics 35 (Suppl 1), 89–94 (2017). https://doi.org/10.1007/s40273-017-0551-z
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DOI: https://doi.org/10.1007/s40273-017-0551-z