**9. Healthcare Structure and the Growing Cost of Care**

Healthcare is funded differently around the world. A broadly speaking socialised healthcare model where treatment is free at the point of access dominates in most of Northern Europe and hybrid schemes with co-payment exist through most of the European Union. Private insurance-based models or self-funded healthcare exists elsewhere. In other words, providing a health episode in some contexts is a societal burden and others an item of service that is associated with a fee and therefore potential profit. The epidemic in thyroid cancer may therefore be seen as a health economic crisis or a wealth opportunity depending on the context in which medicine is practiced.

Studies to explore the economics of the increase in thyroid cancer diagnosis and the associated increase in thyroidectomy rates depending on the health model can be difficult to interpret. In general, cost-effectiveness analyses are hypothetical and present inherent limitations with reproducibility, mainly because of changes in values (probability and cost) over time and the varying model designs [48].

Existing studies on thyroid cancer cost rarely provide a holistic view of the different factors associated with the excess expenditures. Calculations are not contextualised with other cancers and offer an annual estimate of expenditure, without considering the effect of concurrent medical conditions, mental health, and functional status on healthcare expenditures that are paramount to develop future solutions [89,90].

A recent SEER-database study projects the estimated lifetime cost for a hypothetical cohort of individuals with thyroid cancer to be £24,981 per patient, ranging from £24,074 to £42,201 for those with local or metastatic disease respectively. The total cost for an incident cohort of thyroid cancer diagnosed in 2010 was approximately £1 billion and projected to increase to more than £1.7 billion for the 2019 cohort. The total medical cost including diagnosis, treatment, and management for the cohorts diagnosed between 2010 and 2019 is approximately £13.4 billion [91]. Based on the SEER/Medicare data, Boltz et al. estimated the first-year cost for non-metastatic DTC of £12,744 per patient [92]. Berger et al. analysed 183 metastatic thyroid cancers (2003–2005) using a US health insurance claim database estimating the first-year costs to be £43,416 per patient [93]. Another recent study used different US data sources including Medical Expenditure Panel Survey (MEPS) data to estimate the annual direct spending for thyroid cancer to be £3.9 billion in the United States [94]. Lubitz et al, again using the SEER data, conducted a stacked cohort cost analysis from 1985–2013 to estimate current and future healthcare expenditures attributable to well-differentiated thyroid cancer. The current societal costs were estimated to be £1.1 billion in 2013 and predicted to be £2.5 billion in 2030 based on present thyroid cancer incidence trends. The problem is not confined to the US healthcare model.

In Brazil, thyroid cancer increased in incidence from 1.51/100,000 to 4.57/100,000 between 2008 and 2018 with an almost unchanged mortality rate (0.30 to 0.36) [14]. A significant increase in the number of thyroid investigation tools (US, FNA) and treatment/followup procedures (surgery, low dose RAI, US) was noted in all geographic regions during the same period. However, procedures related to more aggressive thyroid cancers (neck dissection, high dose RAI) decreased. Costs of thyroid US increased by 91%, FNA costs by 128%, treatment-related costs by 120%. This resulted in immediate costs to the Brazilian public health system of £29.5 million over 8 years. A similar picture has been highlighted in Australia where the estimated economic burden of "excess" thyroidectomies in New South Wales has been demonstrated as significant [95]. The incidence of DTC and total thyroidectomy both doubled between 2003 and 2012, while the mortality rate remained unchanged. The projected increase of 2196 thyroidectomy procedures translated into an additional cost of over £10 million in surgery-related healthcare expenditure alone over a decade. A similar picture has been found in Hong Kong where numbers of thyroidectomies for cancer increased even excluding incidental PTMC [96] with the associated cost implications of £8334 per patient in the first year.

There are of course large differences in healthcare costs in different countries and comparing different healthcare and reimbursement systems is challenging [97]. One study performed a cost-analysis of thyroid cancer care between the United States and France identifying that the US healthcare system spends nearly £7200 more per patient for initial 1-year management of PTC than in France. The main components contributing to this cost disparity were hospital facility (70%) and nuclear medicine (19%) reimbursements, despite a lesser duration of stay and lower use of RAI in the United States. Most studies, unfortunately, fail to consider the costs of lifelong thyroid substitution and monitoring of long-term follow-up. It is indeed probable that the annual follow-up cost matches the original larger outlay of surgery as previously suggested. In a publicly funded healthcare system, this substantial cost impacts the funds available for the care of other pathologies [83].

An American study calculated the excess healthcare expenditures of the communitydwelling thyroid cancer patients compared to non-cancer controls in a propensity scorematched analysis [98]. The yearly average total healthcare expenditures among adults with thyroid cancer were significantly higher compared to propensity score-matched controls (£6896 vs £4194, *p* = <0.001). Similar observations were found in terms of inpatient and outpatient expenditures.
