Cost-effective strategies in the follow-up of people with confirmed colorectal adenomas for the prevention and early detection of colorectal cancer in the National Health Insurance, South Korea.

Colorectal cancer (CRC) is the third most common cancer amongst South Koreans. Indirect evidence suggested CRC can be prevented, if not cured through the early detection and the subsequent removal of the precursor of CRC using colonoscopy (COL), the colorectal adenoma (polypectomy). The main aim of this thesis is to identify cost-effective strategies in the follow-up of people with confirmed colorectal adenomas (COL surveillance) for the prevention and early detection of colorectal cancer in the colorectal cancer screening (CRCS), National Health Insurance in Korea. To fulfil the main aim of this study, the following specific objectives were carried out: Estimation of adenoma recurrence post-polypectomy, identification of resources used in the CRCS and CRC treatment and the mapping of common pathways in the CRCS – this was achieved through a collaboration with a researcher in Korea by constructing a CRC cohort utilising the NHI data (2009-2012); Examination of the relevant cost-effectiveness evidence of COL surveillance in individuals with adenomas – this was achieved by conducting a review of the cost-effectiveness evidence in the prevention and early detection of CRC; A literature review of the Health State Utility Values (HSUVs) was conducted to identify methodologically robust HSUVs with health states of interest, this information was used for economic evaluation of COL surveillance; Identification of cost-effective strategies for COL surveillance utilising the findings from previous objectives. Results from a de novo cost-utility analysis indicated that a 0LR3HR (a COL 3 years post- polypectomy for high-risk) strategy is expected to be the most cost-effective in the follow-up of people with confirmed adenomas in the CRCS, NHI. The findings of this study will inform the COL surveillance policy in the CRCS, NHI. Approaches taken in this study and the findings can provide a foundation for further comparative policy analyses in other Asian countries where similar rates of CRC are observed.