OBJECTIVES: Economic assessments of healthcare interventions for health technology assessments (HTAs) limit societal impact to productivity losses. Other societal impact has been highlighted by the Covid-19 pandemic that was associated with a severe impairment of the ability of the healthcare system to provide adequate and timely care to patients in many indications due to unprecedented increases in hospitalizations. The impact of healthcare interventions on health care system capacity and security has been identified as a priority value item for consideration by HTA recently. In imperfect markets with permanent excess demand, the accounting costs of resources underestimate their opportunity costs. Hence, reliance on accounting costs in economic evaluations of interventions that can avoid future demand for care leads to undervaluation of these interventions. Attempts have been made to evaluate the value of vaccines by accounting for their impact on health system capacity, through valuing bed-days used by patients with vaccine-preventable disease by their opportunity cost.

METHODS: We apply theoretical methods for calculating opportunity costs of services proposed by Sandmann et al. to interventions in a chronic disease. An example is shown for chronic kidney disease that has high and increasing prevalence, and an associated surge in the demand for renal care services, coupled with supply shortages of dialysis equipment and adequate workforce, creating a situation of permanent overdemand on the market of renal care services. The quantitative magnitude of the undervaluation of delaying dialysis and renal transplant is demonstrated by accounting for opportunity costs of resource use as opposed to valuing used resources on accounting price. Its potential impact on results of economic evaluations of CKD therapies and HTA decisions is shown in a simple model on eGFR slope, and methods are assessed and compared. We generalize our findings to other chronic therapies.