Abstract C124: Past Medical Utilization Patterns as a Key Determinant of Hospital Choice for Cancer Patients in Non-Residential Areas: A National Health Insurance Database Study in Korea
Authors: Ahn Hyo-jeong , Seo Seung Hee , Choi Ji-sook 
Published: September 2024

Abstract
Background The healthcare system in South Korea is facing challenges due to an aging population, resulting in longer hospital stays and increased demand for healthcare services. This demographic shift has the potential to exacerbate healthcare disparities, particularly for cancer patients. This study aims to examine the factors influencing the choice of hospitals outside a cancer patient's residential area, focusing on their past medical utilization patterns. Methods The analysis utilized the claims database from 2018 to 2023 of the Health Insurance Review and Assessment. The study focused on newly diagnosed patients with five types of cancer in 2023: liver, colorectal, gastric, breast, and cervical. The patients' past medical utilization history from 2018 to 2022 was taken into consideration. The Relevance Index (RI) was calculated by dividing the healthcare utilization rate of those who used hospitals located in their residential area by the total healthcare utilization rate at their residence. The RI was then compared across different age groups and four geographical regions (Capital, Central, Southwestern, and Southeastern) using logistic regression. The clustering of past medical utilization patterns was analyzed using k-means clustering. Results The RI values for cancer care have been decreasing across all age groups over the past five years. Specifically, the RI for the under 20 years age group was 50.5% in 2023. When considering residential areas and past medical utilization patterns, the gap widens significantly, ranging from 33.4% to 99.4%. Among the patient’s residences, the central region had the lowest average RI at 71.8% in all age groups, and liver cancer had the highest regional outflow in medical utilization among the five cancer types. The logistic regression analysis identified age group, residence area, and insurance eligibility by household income as significant factors influencing hospital selection outside of the patient's residential area. In some age groups, cancer types were found to be nonsignificant. K-means clustering analysis revealed distinct three clusters of past medical utilization patterns, corresponding to patients with varied experiences at hospitals based on the severity of their disease. Conclusions The decrease in Relative Importance (RI) values across all age groups, especially among cancer patients under 20, highlights concerns about access to optimal cancer care in rural regions. Recognizing the impact of past medical experiences on hospital selection can help improve the accessibility and quality of cancer care in non-residential areas.
Citation Format: Hyo-jeong Ahn, Seung Hee Seo, Ji-sook Choi. Past Medical Utilization Patterns as a Key Determinant of Hospital Choice for Cancer Patients in Non-Residential Areas: A National Health Insurance Database Study in Korea [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C124.