TO THE EDITOR—We thank Dr Robinson for her letter on our study that evaluated the cost-effectiveness of treatments for Clostrioides difficile infection, as recommended by the Infectious Diseases Society of America guidelines. There is no single threshold that can capture society’s evolving willingness to pay for an intervention; $50 000 per quality-adjusted life year (QALY) is a round number yet arbitrary. As Dr Robinson astutely noted, the $50 000 threshold was developed in the 1990s, although its origins are likely from the 1970s when the United States decided that Medicare must cover dialysis for patients with end-stage renal disease [1]. A society’s willingness to pay has likely progressed from 1970 through 1990 and into 2020, if for no other reason other than inflation. The World Health Organization previously recommended costing thresholds based on 2–3 times a nation’s gross domestic product [2]. For the United States, this would result in a minimal threshold of $120 000 to $180 000 per QALY. Thus, our chosen threshold of $100 000 per QALY is conservative.
The cost of a therapy will always need to be interpreted in the context of resources, available budget, and the medical benefits of a therapy to an individual. What is cost-effective is not necessarily affordable. Rising medical costs are clearly of concern, especially in the United States, but a single cutoff can never delineate what is truly cost effective. Regardless, using a threshold of $50 000 per QALY would not change the results of our study.
Notes
Financial Support. R. R. reports grants from National Institute of Allergy and Infectious Diseases (K23AI 138851), during the conduct of the study.
Potential Conflicts of Interest. E. E. reports personal fees from ViiV, outside the submitted work. B. V. reports personal fees from Abbvie and grants from Roche, Takeda, Celgene, and Diasorin, outside the submitted work. R. R. has no potential conflicts to disclose. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.
References
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