The Incidence of Thyroid Cancer Is Affected by the Characteristics of a Healthcare System

The aim of this study was to investigate the associations between the incidence of thyroid cancer and the characteristics of healthcare systems in OECD countries and to demonstrate that the increasing incidence of thyroid cancer is mainly due to overdiagnosis. We used a random effects panel model to regress the incidence of thyroid cancer on the characteristics of healthcare systems (i.e., share of public expenditure on health, mode of health financing, existence of referral system to secondary care, mode of payment to primary care physicians), controlling for macro context variables (i.e., GDP per capita, educational level) on a country level. Data were derived from 34 OECD countries for 2002 and 2008. The share of public expenditure on health was negatively associated with the incidence of thyroid cancer. However, it had no statistically significant effect on the mortality of thyroid cancer and on the incidence of stomach and lung cancer. In the case of colorectal cancer, it had a positive effect on the incidence rate. The upward trend of the incidence of thyroid cancer is closely related to the healthcare system that permits overdiagnosis. Increases in the proportion of public financing may help reduce the overdiagnosis of thyroid cancer.