Medical travel patterns for hepatocellular carcinoma treatment in South Korea: National Health Insurance data from 2013 to 2021

Table 2 Factors affecting initial treatment at hospitals outside of residential regions

Factors	aOR	95%CI
		Low	High
Age in years
00-39	Reference
40-49	0.733	0.661	0.812
50-59	0.649	0.589	0.715
60-69	0.598	0.542	0.659
70-79	0.484	0.438	0.535
≥ 80	0.343	0.304	0.387
Sex
Male	Reference
Female	1.008	0.971	1.047
Residential regions
Seoul	Reference
Busan	15.926	14.189	17.875
Daegu	8.861	7.779	10.093
Incheon	18.344	16.236	20.725
Gwangju	77.516	65.581	91.622
Daejeon	18.307	15.737	21.295
Ulsan	24.560	20.935	28.812
Chungcheong	102.079	90.350	115.330
Gyeonggi	29.790	26.829	33.078
Gangwon	49.107	43.005	56.074
Jeolla	46.179	41.247	51.700
Gyeongsang	110.994	99.196	124.194
Jeju	40.759	34.865	47.650
Year of diagnosis
2013	Reference
2014	1.038	0.973	1.107
2015	1.036	0.972	1.105
2016	0.993	0.931	1.059
2017	0.981	0.920	1.046
2018	0.996	0.934	1.063
2019	0.949	0.889	1.012
2020	0.934	0.875	0.997
2021	0.935	0.874	1.000
CCI
1-2	Reference
3-4	0.936	0.888	0.986
≥ 5	0.819	0.778	0.862
Income level, quintiles
Medicare	Reference
1 (low income)	1.693	1.571	1.825
2	1.66	1.537	1.793
3	1.762	1.635	1.899
4	2.007	1.864	2.161
5 (high income)	2.329	2.166	2.504
Liver cirrhosis
Yes	Reference
No	1.099	1.055	1.145
Extrahepatic metastasis
Yes	Reference
No	1.011	0.964	1.062

aOR: Adjusted odds ratio; CCI: Charlson comorbidity index; CI: Confidence interval.