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Health Inequities in Cancer Incidence According to Economic Status and Regions Are Still Existed Even under Universal Health Coverage System in Korea: A Nationwide Population Based Study Using the National Health Insurance Database

Article information

Cancer Res Treat. 2024;56(2):380-403
Publication date (electronic) : 2023 December 6
doi : https://doi.org/10.4143/crt.2023.650
Youngs Chang1orcid_icon, Soo-Hee Hwang2orcid_icon, Sang-A Cho2, Hyejin Lee3, Eunbyul Cho3, Jin Yong Lee1,2,4orcid_icon
1Department of Health Policy and Management, Seoul National University College of Medicine, Seoul, Korea
2HIRA Research Institute, Health Insurance Review & Assessment Service, Wonju, Korea
3Department of Family Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
4Public Healthcare Center, Seoul National University Hospital, Seoul, Korea
Correspondence: Jin Yong Lee, Public Healthcare Center, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 03080, Korea Tel: 82-2-2072-4293 Fax: 82-2-762-5278 E-mail: jylee2000@gmail.com
*Youngs Chang and Soo-Hee Hwang contributed equally to this work.
Received 2023 May 10; Accepted 2023 December 5.

Abstract

Purpose

The purpose of this study is to determine the level of health equity in relation to cancer incidence.

Materials and Methods

We used the National Health Insurance claims data of the National Health Insurance Service between 2005 and 2022 and annual health insurance and medical aid beneficiaries between 2011 and 2021 to investigate the disparities of cancer incidence. We calculated age-sex standardized cancer incidence rates by cancer and year according to the type of insurance and the trend over time using the annual percentage change. We also compared the hospital type of the first diagnosis by cancer type and year and cancer incidence rates by cancer type and region in 2021 according to the type of insurance.

Results

The total cancer incidence increased from 255,971 in 2011 to 325,772 cases in 2021. The absolute difference of total cancer incidence rate between the NHI beneficiaries and the medical aid (MA) recipients increased from 510.1 cases per 100,000 population to 536.9 cases per 100,000 population. The odds ratio of total cancer incidence for the MA recipients increased from 1.79 (95% confidence interval [CI], 1.77 to 1.82) to 1.90 (95% CI, 1.88 to 1.93). Disparities in access to hospitals and regional cancer incidence were profound.

Conclusion

This study examined health inequities in relation to cancer incidence over the last decade. Cancer incidence was higher in the MA recipients, and the gap was widening. We also found that regional differences in cancer incidence still exist and are getting worse. Investigating these disparities between the NHI beneficiaries and the MA recipients is crucial for implementing of public health policies to reduce health inequities.

Keywords: Health inequities; Cancer incidence; National Health Programs; Korea

Introduction

Despite of substantial advancements in the diagnosis and treatment technologies for cancer, cancer remains a prominent global burden, ranking among the most severe chronic illnesses worldwide. The global burden of disease study revealed that, in 2013, there were 14.9 million reported cancer incidence cases and 8.2 million cancer-related fatalities on a global scale [1]. In South Korea, in 2016, approximately 220,000 individuals were newly diagnosed with cancer, and around 78,000 died from cancer [2].

Several studies reported that there is socioeconomic inequity not only in the treatment of cancer but also in its incidence [3-10]. Several research conducted in Europe have indicated that individuals with low socioeconomic status tend to exhibit higher cancer incidence compared to individuals with high socioeconomic status [6-8].

South Korea is a nation with relatively low financial burdens regarding cancer diagnosis and treatment. The National Health Insurance (NHI) mandates that all citizens enroll in health insurance and provides financial assistance through the medical aid (MA) for those unable to afford medical insurance premiums, Consequently, South Korea achieved universal health coverage (UHC) [11]. Both the NHI and the MA in South Korea are encouraged to get regular cancer screening every 2 years. The out-of-pocket expenses for cancer screening are minimal, with the NHI covering up to 10% of the cost, and the MA offering screening at no cost to promote early cancer detection. Once a cancer diagnosis is confirmed, individuals with cancer are only required to bear 5% of their medical expenses.

The National Cancer Registry is very efficient and provides national cancer statistics. The National Cancer Registry provides highly accurate and detailed information on cancer incidence, mortality, and survival rates by cancer type, age group, sex, and region, including personal information such as patient’s social security number, address, and occupation, as well as various clinical information such as surveillance, epidemiology, and end results stage, metastasis, and differentiation, as well as date and cause of death and type of treatment.

However, this data does not include a variable to categorize the income level of patients, making it difficult to identify differences by economic level, which is one of the important factors in cancer incidence and mortality. The NHI claims data contains information on healthcare utilization related to the occurrence of cancer diseases and information on the type of health insurance coverage, which may indirectly reflect the income of cancer patients. Although more sophisticated results can be obtained by combining the National Cancer Registry data and the NHI claims data through additional work, we utilized the NHI claims data for efficient production of data and securing recent information. Because of the high correlation between the National Cancer Registry data and the NHI claims data on cancer incidence, the NHI claims data can be used to compare health disparities between the NHI beneficiaries and the MA recipients.

In previous studies utilizing the National Cancer Registry in South Korea, the nationwide cancer incidence is well-documented, but there is a lack of data regarding the socioeconomic status. Therefore, we aim to investigate the impact of socioeconomic status on cancer incidence using the NHI claims data. This study aims to investigate under the UHC whether: (1) there exists inequality in cancer incidence based on socioeconomic status, particularly insurance types and geographic regions; (2) whether such inequality is increasing; and (3) whether inequality exists in cancer treatment facilities based on socioeconomic status.

Materials and Methods

1. Data sources

To define patients with newly diagnosed cancer between 2011 and 2021, we used the NHI claims data of the National Health Insurance Service from 2005 through 2022, with a washout period of 5 years and a subsequent 1-year follow-up period to define episodes for patients in 2021. The NHI claims data contains information about patients (age, sex, type of insurance, diagnosis and treatment history, etc.) This is representative of data from almost all citizens, including the NHI and the MA patients [12,13].

Furthermore, we used the National Health Insurance Service’s annual health insurance and medical aid beneficiaries from 2011 to 2021. These statistics include the number of beneficiaries for the NHI and the MA by province, age, and sex at the end of each year [14].

2. Definitions

All inpatient and outpatient claim with a primary diagnosis of C00-C96 according to the Korean Standard Classification of Diseases and Causes of Death-8 (KCD-8) and a special benefit code for registered cancer patients (V193) were extracted and considered as medical utilization due to cancer. All cancers were categorized as the 10 most diagnosed cancers in Korea based on the National Cancer Registry Statistics 2019, and the rest were categorized as other cancers. The 10 cancers included thyroid cancer (C73), lung cancer (C33-C34), colorectal cancer (C18-C20), stomach cancer (C16), breast cancer (C50), prostate cancer (C61), liver cancer (C22), pancreatic cancer (C25), gallbladder and biliary tract cancer (C23-C24), and kidney cancer (C64) [15].

We constructed episodes of patients’ healthcare use with data classified by cancer type to define a newly diagnosed cancer case. The first episode by year established between 2011 and 2021 was defined as a newly diagnosed cancer case (new claim for major diagnosis of C code and V193; special certification for cancer) in the year if there was no healthcare use due to the same cancer in the previous 5 years.

The hospital type of the first diagnosis was defined as the type of hospital used by the patient in the first episode of healthcare use due to specific cancer. It was classified into tertiary hospitals, general hospitals, hospitals, and clinics.

Geographic regions were defined based on the residence of patients diagnosed with new cancer and categorized into 17 provinces according to the administrative divisions of the Korean Ministry of the Interior and Safety.

3. Statistical analysis

General characteristics and the hospital type of the first diagnosis are presented as mean and standard deviation or number and percentage. The age-sex standardized cancer incidence rates by cancer type and year according to the type of insurance and the age-sex standardized cancer incidence rate by cancer type and province in 2021 according to the type of insurance were presented as the number of diagnosed cancer cases per 100,000 population of beneficiaries. Age standardization was performed using 10-year age groups, except that age standardization by region was done for those under age 60 and over age 60 due to few occurrences per cell. To determine the trend in cancer incidence over time by a different type of insurance, a log-linear Poisson regression model was used to compare the annual percentage change (APC). The odds ratio (OR) with 95% confidence intervals was also calculated using the NHI group as a reference to compare the risk of new cancer incidence between two health insurance types. The statistical significance level was set to 0.05. All statistical analyses in this study were calculated using SAS software ver. 9.4 (SAS Institute Inc., Cary, NC).

Results

1. General characteristics of cancer patients in Korea

The trend of total cancer incidence increased from 255,971 cases in 2011 to 325,772 cases in 2021. The cancers that have increased the most are, in order, breast cancer, prostate cancer, lung cancer, colorectal cancer, pancreatic cancer, kidney cancer, and gallbladder cancer. Cancers whose incidence has plateaued or declined are thyroid cancer, stomach cancer, and liver cancer. Breast cancer cases were 18,362 and 32,541 in 2011 and 2021, lung cancer cases were 22,166 and 31,637 in 2011 and 2021, and colorectal cancer cases were 28,905 and 35,258 in 2011 and 2021. Among total cancer cases, thyroid cancer had the highest incidence and decreasing trend, with 41,700 cases in 2011 to 37,166 cases in 2021. Stomach cancer cases were 33,368 and 31,517 in 2011 and 2021, and liver cancer cases were 18,455 and 17,668 in 2011 and 2021.

By age group, the number and proportion of total cancer cases were prominent in 50-59 years, 60-69 years, and 70-79 years age group, while the proportion of total cancer cases was less than 2% in the ≤ 29 years age group. In addition, the proportion of sex was similar between male and female, about 95% of total cancer cases were covered by the NHI, and about 5% were the MA recipients. The general characteristics of the study subjects are shown in Tables 1, 2 and S1 Table.

General characteristics of study subjects (thyroid cancer, lung cancer, colorectal cancer, stomach cancer, breast cancer, and prostate cancer): year 2011-2016

General characteristics of study subjects (thyroid cancer, lung cancer, colorectal cancer, stomach cancer, breast cancer, and prostate cancer): year 2017-2021

2. Age-sex standardized total cancer incidence by insurance type

As shown in Fig. 1 and S2 Table, The total cancer incidence rate showed an increasing trend, as did the NHI and the MA group. The gap between the NHI group and the MA group has widened from 2011 to 2021. The gap was lowest in 2012, with 434.1 cases per 100,000 population, and highest in 2016 at 550.1 cases per 100,000 population. By insurance type, the MA group had the higher cancer incidence rate than the NHI group. The total incidence rate of the NHI decreased from 652.0 cases per 100,000 population in 2011 to 600.4 cases per 100,000 population, whereas the total incidence rate of the MA decreased from 1,162.1 cases per 100,000 population in 2011 to 1,137.3 cases per 100,000 population. The absolute difference of total cancer incidence rate was 510.1 cases per 100,000 population in 2011 and 536.9 cases per 100,000 population in 2021. The APC in total cancer in total population was –1.06%-point, with –1.12%-point, and –0.02%-point in the NHI and the MA groups. The incidence of all types of cancer was higher in the MA group, except thyroid cancer. The incidence of liver cancer and stomach cancer was in a decreasing pattern in the NHI group, –3.88%-point and –4.44%-point, respectively.

Fig. 1.

Yearly age-sex standardized cancer incidence rates by cancer type (Units: cases per 100,000 population). APC, annual percentage change; MA, medical aid; NHI, National Health Insurance. *p < 0.05.

3. The OR of cancer incidence by insurance type

As Fig. 2 and S3 Table show the OR of cancer incidence by insurance type, the risk of total cancer incidence raised from 2011 to 2021. The OR of total cancer incidence showed an increasing pattern, with 1.79 (95% confidence interval [CI], 1.77 to 1.82), and 1.90 (95% CI, 1.88 to 1.93) in 2011 and 2021, respectively. The risk of all types of cancer incidence except thyroid cancer was significantly higher in the MA group than in the NHI group which is the reference. Cancers that have shown an increasing trend of the OR were lung cancer, colorectal cancer, stomach cancer, liver cancer, pancreatic cancer, gallbladder cancer, and kidney cancer. The OR of liver cancer was the highest among 10 types of cancer, 2.43 (95% CI, 2.31 to 2.54) in 2011 and 2.76 (95% CI, 2.61 to 2.92) in 2021. A decreasing trend of the OR was shown in breast cancer and prostate cancer. The OR of breast cancer was 1.32 (95% CI, 1.23 to 1.41), 1.18 (95% CI, 1.11 to 1.25) in 2011 and 2021. Only the OR of thyroid cancer incidence was less than 1. The OR was 0.67 (95% CI, 0.63 to 0.72) and 0.68 (95% CI, 0.63 to 0.73) in 2011 and 2021, respectively.

Fig. 2.

Yearly odds ratio of cancer incidence by cancer type with 95% confidence interval (ref: the National Health Insurance).

4. Disparities in hospital type of first diagnosis in cancer

In the MA group, the proportion of general hospitals was higher than the proportion of tertiary hospitals, with 61.4% of general hospitals and 28.5% of tertiary hospitals in 2011. However, the gap between general hospitals and tertiary hospitals has narrowed, with 38.7% of general hospitals and 54.0% of tertiary hospitals in 2021. Fig. 3 and S4-S6 Tables show the proportion of the type of hospital where patients were first diagnosed with cancer. The proportion was highest in tertiary hospitals, followed by general hospitals, hospitals, and local clinics in the NHI group. The sum of proportion of hospitals and local clinics was less than 10% in both groups. Since 2017, the proportion of tertiary hospitals for the first cancer diagnosis in the MA group has increased, however, it is still approximately 10% different from the NHI group.

Fig. 3.

Hospital types at the first diagnosis of cancer by year (Units: %). MA, medical aid; NHI, National Health Insurance.

5. Regional disparities in cancer incidence by insurance type

All regions showed differences in cancer incidence by insurance type. The cancer incidence rate was higher in the MA group than in the NHI group in every province. Fig. 4 and S7 Table show the regional disparities in cancer incidence by insurance type in 2021. Nationwide total cancer incidence rates were 605.4 cases per 100,000 population. Nationwide cancer incidence rates in the NHI and the MA groups were 589.9 cases per 100,000 population and 1,133.1 cases per 100,000 population. Disparities between insurance types also vary by region, with most provinces showing gap of approximately two-to-one between the NHI and the MA groups, while some provinces showed a smaller gap. Busan had the highest overall cancer rate at 646.1 cases per 100,000 population, while Jeju had the lowest overall cancer rate at 570.4 cases per 100,000 population.

Fig. 4.

Age-sex standardized cancer incidence rates by region and insurance type in 2021 (Units: cases per 100,000 population). MA, medical aid; NHI, National Health Insurance.

Discussion

This study is the first paper to examine health inequities in relation to cancer incidence between the NHI beneficiaries and the MA recipients over the last decade in Korea. Cancer incidence has increased overall, and this trend was found in both the NHI group and the MA group. However, we found that cancer incidence was higher in the MA group than in the NHI group, and that the gap was widening. We also found that regional differences in cancer incidence still exist and are getting worse.

In addition, the risk of cancer incidence showed the same pattern as cancer incidence rates. The OR was higher in the MA group than in the NHI group. The OR of total cancer incidence was 1.79 (95% CI, 1.77 to 1.82) and 1.90 (95% CI, 1.88 to 1.93) in 2011 and 2021. Only the OR for thyroid cancer was conversely lower in the MA group, at 0.67 (95% CI, 0.63 to 0.72) and 0.68 (95% CI, 0.63 to 0.73) in 2011 and 2021, respectively. The reason why thyroid cancer tended to be different from other cancers is due to specific characteristic of thyroid cancer and thyroid cancer patients. Mortality of thyroid cancer is exceptionally low compared to other cancers, and thyroid cancer is known to be more affected by high socioeconomic factors such as income. People with high income tend to use more medical services than people with low income and are more at risk of overutilization [16-19]. High-income patients tend to be screened with more sensitive tests, and such tendency may lead to earlier diagnosis, increasing the possibility of overdiagnosis [19-21]. Such characteristics of thyroid cancer patients may have influenced the results that thyroid cancer has the highest number of patients of all cancers.

Assuming that even within the same region there are differences in the choice of higher level of care for socioeconomic reasons, we analyzed whether there were differences by type of initial diagnosis. The proportion of the type of hospital where patients were first diagnosed with cancer was different between the NHI and the MA groups. More than 60% of cancer incidence in the NHI beneficiaries was diagnosed at tertiary hospitals and around 30% at general hospitals. On the other hand, general hospitals were where ≥ 60% of cancer cases of the MA recipients were diagnosed between 2011 and 2016. This represents that the NHI beneficiaries could afford to pay more medical expenses while the MA recipients are financially vulnerable. However, in the MA group, the proportion of cancer diagnosis at tertiary hospitals increased from 28.5% in 2011 to 54.0% in 2021, while the proportion at general hospitals decreased from 61.4% in 2011 to 38.7% in 2021. These changes have been significant since 2017 for most cancers. We could possibly interpret this result as enhanced cancer coverage by the NHI. Under the health insurance coverage enhancement policy implemented since 2017, the upper limit of health insurance deductibles paid by the lowest 50% of income earners was reduced to 10% of their annual income. In addition to expanding rebates for low-income earners, the catastrophic medical expense support program, which covers therapeutic out-of-pocket medical expenses, was expanded from four serious diseases to all diseases, and the maximum amount of support was raised from KRW 20 million to KRW 30 million (USD 15,000 to USD 24,000).

In Korea, when a person is diagnosed with cancer of any type, the NHI covers 95% of medical expenses. Cancer patients pay only 5% of total cancer treatment expenses regardless of their health coverage. Cancer patients burden 5% of treatment expenses from out-of-pocket, therefore we may assume that cancer patients in the MA group feel less burdened by treatment costs, resulting in an increased proportion of tertiary hospitals in the first diagnosis of cancer. Despite an increase in the proportion of the MA patients diagnosed with cancer at tertiary hospitals, it was still about 10% lower than in the NHI group, and disparity still existed.

This study has some limitations. First, we used only cancer incidence as the outcome variable in this study. Health inequity would be ideal if it did not exist. However, unfortunately, inequity exists in the real world. Accurately measuring the magnitude of inequity is important. Therefore, choosing appropriate health inequity indicators is inevitable to measure health inequity. Four perspectives are considered when conducting research regarding cancer: treatment, mortality, screening, and stage. In this study, we could not afford to take cancer treatment, cancer mortality, and stage as outcome variables due to data structure. However, cancer incidence may be appropriate outcome variable in Korea. As stated above, with the low cost of treatment, there would be less reason for newly diagnosed cancer patients not to have medical treatment. Further research would be necessary to evaluate health disparities in cancer using other outcome variables such as treatment, mortality, stage, etc. Second, our results cannot provide information regarding the impact of coronavirus disease 2019 (COVID-19) on cancer patients in 2020 and 2021. As no conclusive evidence of carcinogenesis of COVID-19 has been established, we ruled out the risk of COVID-19. Third, while it is common to use cancer registry data to study cancer incidence or mortality, we were unable to use a variable for type of health insurance, which is the minimum variable to distinguish the economic level that is the main interest of this study. Instead, we used health insurance claims data, which can be used to manipulatively define new cancers through healthcare use by the total population. By using the primary diagnosis and a special benefit code for cancer, the accuracy of the data can be improved and considered reliable. Seo et al. [22] investigated that cancer incidence rates between the National Cancer Registry and the NHI claims data were very similar, with 363.1 cases per 100,000 population in the NHI claims data and 361.9 cases per 100,000 population in the National Cancer Registry data from 2005-2008.

In terms of future policy recommendations, it would be ideal if the National Cancer Registry data included an indicator of income. Currently, there are no income indicators in the National Cancer Registry data, so we are forced to use the NHI claims data. If it is not possible to add an income indicator to the National Cancer Registry data, it is essential to cooperate with relevant organizations to link the NHI claims data.

In conclusion, this study investigated that socioeconomic disparities in cancer incidence have worsened by health coverage, region, and over the study period. Nevertheless, increased health coverage may have influenced the proportion of tertiary hospitals in the MA group. Understanding these disparities is crucial for implementing of public health policies to reduce health inequality.

Electronic Supplementary Material

Supplementary materials are available at Cancer Research and Treatment website (https://www.e-crt.org).

Notes

Ethical Statement

This study was reviewed and approved by the institutional review board (IRB) of Seoul National University Bundang Hospital (IRB No. X-2304-820-902). Informed consent was waived as we used anonymized data.

Author Contributions

Conceived and designed the analysis: Chang Y, Hwang SH, Lee H, Lee JY.

Collected the data: Hwang SH, Cho SA, Lee JY.

Contributed data or analysis tools: Hwang SH, Cho SA, Lee JY.

Performed the analysis: Hwang SH, Cho SA.

Wrote the paper: Chang Y, Hwang SH.

Review and Interpretation: Chang Y, Hwang SH, Cho SA, Lee H, Cho E, Lee JY.

Conflicts of Interest

Conflict of interest relevant to this article was not reported.

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Article information Continued

Copyright © 2024 by the Korean Cancer Association

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Fig. 1.

Fig. 1.

Yearly age-sex standardized cancer incidence rates by cancer type (Units: cases per 100,000 population). APC, annual percentage change; MA, medical aid; NHI, National Health Insurance. *p < 0.05.

Fig. 2.

Fig. 2.

Yearly odds ratio of cancer incidence by cancer type with 95% confidence interval (ref: the National Health Insurance).

Fig. 3.

Fig. 3.

Hospital types at the first diagnosis of cancer by year (Units: %). MA, medical aid; NHI, National Health Insurance.

Fig. 4.

Fig. 4.

Age-sex standardized cancer incidence rates by region and insurance type in 2021 (Units: cases per 100,000 population). MA, medical aid; NHI, National Health Insurance.

Table 1.

General characteristics of study subjects (thyroid cancer, lung cancer, colorectal cancer, stomach cancer, breast cancer, and prostate cancer): year 2011-2016

2011
 2012
 2013
 2014
 2015
 2016
No. or Mean % or SD No. or Mean % or SD No. or Mean % or SD No. or Mean % or SD No. or Mean % or SD No. or Mean % or SD
Total insurance
 Total 50,908,646 51,169,141 51,448,491 51,757,146 52,034,424 52,272,755
 NHI beneficiaries 49,299,165 96.8 49,662,097 97.1 49,989,620 97.2 50,316,384 97.2 50,490,157 97.0 50,763,283 97.1
 MA recipients 1,609,481 3.2 1,507,044 2.9 1,458,871 2.8 1,440,762 2.8 1,544,267 3.0 1,509,472 2.9
Total cancer (sum)
 Total N
  No. of patients 255,971 260,617 264,890 260,175 256,986 280,040
 Age (yr)
  Age_Mean 59.9 15.0 60.2 14.9 60.6 14.9 61.3 14.9 62.0 14.9 62.3 14.9
 Age group (yr)
  < 20 2,326 0.9 1,975 0.8 1,811 0.7 1,841 0.7 1,804 0.7 1,905 0.7
  20-29 4,146 1.6 4,076 1.6 4,071 1.5 3,933 1.5 3,465 1.3 4,110 1.5
  30-39 16,566 6.5 16,518 6.3 16,447 6.2 14,527 5.6 13,009 5.1 13,896 5.0
  40-49 37,725 14.7 37,336 14.3 38,108 14.4 34,903 13.4 32,661 12.7 34,412 12.3
  50-59 60,150 23.5 61,325 23.5 61,226 23.1 58,470 22.5 56,044 21.8 59,569 21.3
  60-69 58,483 22.8 58,318 22.4 58,480 22.1 58,790 22.6 60,658 23.6 67,651 24.2
  70-79 56,319 22.0 59,179 22.7 60,835 23.0 61,356 23.6 60,693 23.6 65,246 23.3
  ≥ 80 20,256 7.9 21,890 8.4 23,912 9.0 26,355 10.1 28,652 11.1 33,251 11.9
 Sex
  Male 129,084 50.4 130,245 50.0 132,956 50.2 133,727 51.4 134,494 52.3 145,340 51.9
  Female 126,887 49.6 130,372 50.0 131,934 49.8 126,448 48.6 122,492 47.7 134,700 48.1
 Insurance
  NHI beneficiaries 242,583 94.8 248,441 95.3 252,499 95.3 247,269 95.0 244,031 95.0 265,411 94.8
  MA recipients 13,388 5.2 12,176 4.7 12,391 4.7 12,906 5.0 12,955 5.0 14,629 5.2
Thyroid
 Total N
  No. of patients 41,700 45,915 44,456 33,512 26,066 27,704
 Age (yr)
  Age_Mean 48.6 12.0 49.0 12.2 48.7 12.3 48.7 12.5 48.6 12.8 48.7 13.1
 Age group (yr)
  < 20 168 0.4 165 0.4 172 0.4 180 0.5 156 0.6 148 0.5
  20-29 1,900 4.6 1,992 4.3 2,079 4.7 1,758 5.2 1,433 5.5 1,713 6.2
  30-39 7,711 18.5 8,273 18.0 8,201 18.4 6,031 18.0 4,840 18.6 5,236 18.9
  40-49 12,218 29.3 12,817 27.9 12,842 28.9 9,509 28.4 7,397 28.4 7,661 27.7
  50-59 12,302 29.5 13,875 30.2 12,986 29.2 9,719 29.0 7,179 27.5 7,302 26.4
  60-69 5,295 12.7 6,253 13.6 5,753 12.9 4,435 13.2 3,561 13.7 3,856 13.9
  70-79 1,890 4.5 2,261 4.9 2,130 4.8 1,626 4.9 1,255 4.8 1,464 5.3
  ≥ 80 216 0.5 279 0.6 293 0.7 254 0.8 245 0.9 324 1.2
 Sex
  Male 7,261 17.4 8,281 18.0 8,726 19.6 6,643 19.8 5,562 21.3 5,832 21.1
  Female 34,439 82.6 37,634 82.0 35,730 80.4 26,869 80.2 20,504 78.7 21,872 78.9
 Insurance
  NHI beneficiaries 40,787 97.8 45,091 98.2 43,646 98.2 32,856 98.0 25,553 98.0 27,104 97.8
  MA recipients 913 2.2 824 1.8 810 1.8 656 2.0 513 2.0 600 2.2
Lung
 Total N
  No. of patients 22,166 22,618 23,719 24,631 24,887 27,093
 Age (yr)
  Age_Mean 67.9 11.4 68.3 11.2 68.5 11.3 68.9 11.3 69.0 11.3 69.1 11.3
 Age group (yr)
  < 20 12 0.1 14 0.1 17 0.1 8 0 15 0.1 19 0.1
  20-29 52 0.2 38 0.2 46 0.2 46 0.2 43 0.2 48 0.2
  30-39 240 1.1 215 1.0 223 0.9 245 1.0 221 0.9 219 0.8
  40-49 1,101 5.0 1,028 4.5 1,019 4.3 1,031 4.2 1,005 4.0 1,037 3.8
  50-59 3,574 16.1 3,567 15.8 3,736 15.8 3,686 15.0 3,674 14.8 3,962 14.6
  60-69 6,236 28.1 6,115 27.0 6,284 26.5 6,483 26.3 6,749 27.1 7,633 28.2
  70-79 7,855 35.4 8,292 36.7 8,783 37.0 9,065 36.8 8,885 35.7 9,224 34.0
  ≥ 80 3,096 14.0 3,349 14.8 3,611 15.2 4,067 16.5 4,295 17.3 4,951 18.3
 Sex
  Male 15,470 69.8 15,577 68.9 16,467 69.4 17,091 69.4 17,375 69.8 18,536 68.4
  Female 6,696 30.2 7,041 31.1 7,252 30.6 7,540 30.6 7,512 30.2 8,557 31.6
 Insurance
  NHI beneficiaries 20,635 93.1 21,122 93.4 22,195 93.6 23,031 93.5 23,242 93.4 25,296 93.4
  MA recipients 1,531 6.9 1,496 6.6 1,524 6.4 1,600 6.5 1,645 6.6 1,797 6.6
Colon and rectum
 Total N
  No. of patients 28,905 29,550 29,198 28,801 28,517 30,498
 Age (yr)
  Age_Mean 64.2 12.4 64.4 12.5 64.8 12.6 65.2 12.7 65.7 12.7 66.0 12.8
 Age group (yr)
  < 20 16 0.1 15 0.1 9 0 9 0 10 0 18 0.1
  20-29 109 0.4 108 0.4 82 0.3 119 0.4 101 0.4 119 0.4
  30-39 708 2.4 753 2.5 750 2.6 654 2.3 632 2.2 654 2.1
  40-49 2,598 9.0 2,613 8.8 2,526 8.7 2,380 8.3 2,199 7.7 2,272 7.4
  50-59 6,682 23.1 6,729 22.8 6,605 22.6 6,426 22.3 6,098 21.4 6,383 20.9
  60-69 8,148 28.2 7,941 26.9 7,614 26.1 7,479 26.0 7,542 26.4 8,226 27.0
  70-79 7,801 27.0 8,232 27.9 8,123 27.8 8,021 27.8 7,937 27.8 8,127 26.6
  ≥ 80 2,843 9.8 3,159 10.7 3,489 11.9 3,713 12.9 3,998 14.0 4,699 15.4
 Sex
  Male 17,528 60.6 17,761 60.1 17,588 60.2 17,166 59.6 16,924 59.3 18,102 59.4
  Female 11,377 39.4 11,789 39.9 11,610 39.8 11,635 40.4 11,593 40.7 12,396 40.6
 Insurance
  NHI beneficiaries 27,307 94.5 28,057 94.9 27,712 94.9 27,270 94.7 26,949 94.5 28,691 94.1
  MA recipients 1,598 5.5 1,493 5.1 1,486 5.1 1,531 5.3 1,568 5.5 1,807 5.9
Stomach
 Total N
  No. of patients 33,368 32,234 31,686 31,426 30,791 32,743
 Age (yr)
  Age_Mean 63.3 12.6 63.7 12.6 64.2 12.6 64.4 12.6 64.7 12.6 65.2 12.4
 Age group (yr)
  < 20 8 0 6 0 5 0 2 0 4 0 4 0
  20-29 128 0.4 107 0.3 88 0.3 86 0.3 62 0.2 75 0.2
  30-39 999 3.0 897 2.8 823 2.6 731 2.3 701 2.3 670 2.0
  40-49 3,639 10.9 3,251 10.1 3,159 10.0 3,158 10.0 2,933 9.5 2,899 8.9
  50-59 7,846 23.5 7,472 23.2 7,212 22.8 6,996 22.3 6,762 22.0 7,067 21.6
  60-69 8,931 26.8 8,458 26.2 8,286 26.2 8,304 26.4 8,411 27.3 9,130 27.9
  70-79 8,777 26.3 8,931 27.7 8,783 27.7 8,555 27.2 8,132 26.4 8,599 26.3
  ≥ 80 3,040 9.1 3,112 9.7 3,330 10.5 3,594 11.4 3,786 12.3 4,299 13.1
 Sex
  Male 22,486 67.4 21,815 67.7 21,237 67.0 21,163 67.3 20,682 67.2 22,075 67.4
  Female 10,882 32.6 10,419 32.3 10,449 33.0 10,263 32.7 10,109 32.8 10,668 32.6
 Insurance
  NHI beneficiaries 31,674 94.9 30,713 95.3 30,189 95.3 29,844 95.0 29,321 95.2 31,156 95.2
  MA recipients 1,694 5.1 1,521 4.7 1,497 4.7 1,582 5.0 1,470 4.8 1,587 4.8
Breast
 Total N
  No. of patients 18,362 18,441 19,472 20,600 21,774 25,014
 Age (yr)
  Age_Mean 51.8 11.3 52.3 11.4 52.3 11.4 52.7 11.5 53.0 11.5 53.5 11.7
 Age group (yr)
  < 20 7 0 5 0 4 0 4 0 4 0 3 0
  20-29 175 1.0 176 1.0 167 0.9 163 0.8 163 0.7 187 0.7
  30-39 1,975 10.8 1,782 9.7 1,834 9.4 1,899 9.2 1,808 8.3 2,085 8.3
  40-49 6,259 34.1 6,252 33.9 6,680 34.3 6,894 33.5 7,197 33.1 8,071 32.3
  50-59 5,851 31.9 5,783 31.4 6,183 31.8 6,591 32.0 6,897 31.7 7,758 31.0
  60-69 2,611 14.2 2,751 14.9 2,799 14.4 3,040 14.8 3,575 16.4 4,227 16.9
  70-79 1,211 6.6 1,393 7.6 1,459 7.5 1,584 7.7 1,668 7.7 2,050 8.2
  ≥ 80 273 1.5 299 1.6 346 1.8 425 2.1 462 2.1 633 2.5
 Sex
  Male 130 0.7 109 0.6 96 0.5 112 0.5 116 0.5 115 0.5
  Female 18,232 99.3 18,332 99.4 19,376 99.5 20,488 99.5 21,658 99.5 24,899 99.5
 Insurance
  NHI beneficiaries 17,584 95.8 17,804 96.5 18,827 96.7 19,907 96.6 21,024 96.6 24,134 96.5
  MA recipients 778 4.2 637 3.5 645 3.3 693 3.4 750 3.4 880 3.5
Prostate
 Total N
  No. of patients (yr) 9,621 9,777 10,145 10,406 10,691 12,447
 Age
  Age_Mean 70.5 8.4 70.8 8.5 70.6 8.4 70.9 8.4 71.1 8.5 71.2 8.5
 Age group (yr)
  < 20 3 0 3 0 - 0 2 0 2 0 - 0
  20-29 1 0 1 0 2 0 1 0 3 0 2 0
  30-39 10 0.1 5 0.1 3 0 1 0 4 0 2 0
  40-49 77 0.8 69 0.7 80 0.8 72 0.7 59 0.6 91 0.7
  50-59 867 9.0 897 9.2 947 9.3 953 9.2 945 8.8 1,049 8.4
  60-69 3,200 33.3 3,029 31.0 3,147 31.0 3,202 30.8 3,405 31.8 3,980 32.0
  70-79 4,234 44.0 4,403 45.0 4,632 45.7 4,674 44.9 4,615 43.2 5,344 42.9
  ≥ 80 1,229 12.8 1,370 14.0 1,334 13.1 1,501 14.4 1,658 15.5 1,979 15.9
 Sex
  Male 9,621 100 9,777 100 10,145 100 10,406 100 10,691 100 12,447 100
 Insurance
  NHI beneficiaries 9,157 95.2 9,415 96.3 9,742 96.0 9,999 96.1 10,248 95.9 11,940 95.9
  MA recipients 464 4.8 362 3.7 403 4.0 407 3.9 443 4.1 507 4.1

MA, medical aid; NHI, National Health Insurance; SD, standard deviation.

Table 2.

General characteristics of study subjects (thyroid cancer, lung cancer, colorectal cancer, stomach cancer, breast cancer, and prostate cancer): year 2017-2021

2017
 2018
 2019
 2020
 2021
No. or Mean % or SD No. or Mean % or SD No. or Mean % or SD No. or Mean % or SD No. or Mean % or SD
Total insurance
 Total 52,426,625 52,556,653 52,880,293 52,870,968 52,928,662
 NHI beneficiaries 50,940,885 97.2 51,071,982 97.2 51,391,447 97.2 51,344,938 97.1 51,412,137 97.1
 MA recipients 1,485,740 2.8 1,484,671 2.8 1,488,846 2.8 1,526,030 2.9 1,516,525 2.9
Total cancer (sum)
 Total N
  No. of patients 282,134 287,489 300,433 293,644 325,772
 Age (yr)
  Age_Mean 62.7 14.9 62.8 14.9 63.1 14.9 63.3 15.0 63.1 15.1
 Age group (yr)
  < 20 1,629 0.6 1,529 0.5 1,503 0.5 1,522 0.5 1,570 0.5
  20-29 3,912 1.4 4,182 1.5 4,449 1.5 4,553 1.6 5,337 1.6
  30-39 13,840 4.9 14,479 5.0 14,615 4.9 14,116 4.8 16,257 5.0
  40-49 34,109 12.1 33,883 11.8 34,309 11.4 32,852 11.2 37,481 11.5
  50-59 57,889 20.5 57,917 20.1 59,192 19.7 55,682 19.0 60,268 18.5
  60-69 68,500 24.3 70,198 24.4 75,109 25.0 74,988 25.5 85,384 26.2
  70-79 66,736 23.7 67,711 23.6 70,431 23.4 68,482 23.3 73,180 22.5
  ≥ 80 35,519 12.6 37,590 13.1 40,825 13.6 41,449 14.1 46,295 14.2
 Sex
  Male 147,244 52.2 150,562 52.4 156,603 52.1 153,692 52.3 167,759 51.5
  Female 134,890 47.8 136,927 47.6 143,830 47.9 139,952 47.7 158,013 48.5
 Insurance
  NHI beneficiaries 267,448 94.8 272,481 94.8 284,681 94.8 278,149 94.7 308,526 94.7
  MA recipients 14,686 5.2 15,008 5.2 15,752 5.2 15,495 5.3 17,246 5.3
Thyroid
 Total N
  No. of patients 27,567 30,004 32,758 31,362 37,166
 Age (yr)
  Age_Mean 48.6 13.2 48.5 13.3 48.8 13.3 48.4 13.4 48.6 13.5
 Age group (yr)
  < 20 164 0.6 147 0.5 159 0.5 166 0.5 171 0.5
  20-29 1,710 6.2 1,976 6.6 2,152 6.6 2,264 7.2 2,602 7.0
  30-39 5,387 19.5 6,011 20.0 6,277 19.2 6,131 19.5 7,228 19.4
  40-49 7,518 27.3 8,109 27.0 8,730 26.6 8,324 26.5 9,839 26.5
  50-59 7,124 25.8 7,598 25.3 8,427 25.7 7,703 24.6 8,893 23.9
  60-69 3,923 14.2 4,214 14.0 4,767 14.6 4,783 15.3 6,013 16.2
  70-79 1,409 5.1 1,596 5.3 1,840 5.6 1,602 5.1 1,922 5.2
  ≥ 80 332 1.2 353 1.2 406 1.2 389 1.2 498 1.3
 Sex
  Male 6,216 22.5 6,966 23.2 7,909 24.1 7,748 24.7 9,111 24.5
  Female 21,351 77.5 23,038 76.8 24,849 75.9 23,614 75.3 28,055 75.5
 Insurance
  NHI beneficiaries 27,033 98.1 29,387 97.9 32,108 98.0 30,780 98.1 36,438 98.0
  MA recipients 534 1.9 617 2.1 650 2.0 582 1.9 728 2.0
Lung
 Total N
  No. of patients 28,010 29,323 30,302 29,494 31,637
 Age (yr)
  Age_Mean 69.5 11.1 69.7 11.1 69.9 11.0 70.1 11.0 70.2 11.0
 Age group (yr)
  < 20 6 0 5 0 7 0 7 0 3 0
  20-29 44 0.2 41 0.1 45 0.1 38 0.1 45 0.1
  30-39 185 0.7 221 0.8 232 0.8 212 0.7 235 0.7
  40-49 1,048 3.7 1,027 3.5 998 3.3 931 3.2 992 3.1
  50-59 3,917 14.0 3,903 13.3 3,825 12.6 3,538 12.0 3,733 11.8
  60-69 7,818 27.9 8,256 28.2 8,561 28.3 8,598 29.2 9,421 29.8
  70-79 9,718 34.7 10,149 34.6 10,470 34.6 10,077 34.2 10,581 33.4
  ≥ 80 5,274 18.8 5,721 19.5 6,164 20.3 6,093 20.7 6,627 20.9
 Sex
  Male 19,153 68.4 19,905 67.9 20,397 67.3 19,998 67.8 21,079 66.6
  Female 8,857 31.6 9,418 32.1 9,905 32.7 9,496 32.2 10,558 33.4
 Insurance
  NHI beneficiaries 26,072 93.1 27,322 93.2 28,242 93.2 27,383 92.8 29,397 92.9
  MA recipients 1,938 6.9 2,001 6.8 2,060 6.8 2,111 7.2 2,240 7.1
Colon and rectum
 Total N
  No. of patients 30,361 29,798 30,728 29,196 35,258
 Age (yr)
  Age_Mean 66.0 13.0 66.4 13.0 66.4 13.1 66.2 13.4 64.9 14.2
 Age group (yr)
  < 20 13 0 7 0 10 0 12 0 9 0
  20-29 122 0.4 108 0.4 131 0.4 136 0.5 275 0.8
  30-39 658 2.2 682 2.3 675 2.2 736 2.5 1,358 3.9
  40-49 2,348 7.7 2,199 7.4 2,217 7.2 2,242 7.7 3,450 9.8
  50-59 6,301 20.8 6,017 20.2 6,105 19.9 5,755 19.7 6,832 19.4
  60-69 7,986 26.3 7,840 26.3 8,315 27.1 7,894 27.0 9,486 26.9
  70-79 8,023 26.4 7,824 26.3 7,800 25.4 7,168 24.6 7,907 22.4
  ≥ 80 4,910 16.2 5,121 17.2 5,475 17.8 5,253 18.0 5,941 16.9
 Sex
  Male 17,980 59.2 17,743 59.5 18,135 59.0 17,277 59.2 20,678 58.6
  Female 12,381 40.8 12,055 40.5 12,593 41.0 11,919 40.8 14,580 41.4
 Insurance
  NHI beneficiaries 28,557 94.1 28,024 94.0 28,747 93.6 27,310 93.5 33,097 93.9
  MA recipients 1,804 5.9 1,774 6.0 1,981 6.4 1,886 6.5 2,161 6.1
Stomach
 Total N
  No. of patients 31,976 30,888 31,103 28,282 31,517
 Age (yr)
  Age_Mean 65.3 12.4 65.6 12.3 66.0 12.3 66.6 12.3 66.8 12.1
 Age group (yr)
  < 20 5 0 3 0 1 0 2 0 - 0
  20-29 59 0.2 60 0.2 70 0.2 54 0.2 62 0.2
  30-39 611 1.9 563 1.8 513 1.6 430 1.5 387 1.2
  40-49 2,748 8.6 2,519 8.2 2,335 7.5 1,982 7.0 2,134 6.8
  50-59 6,777 21.2 6,498 21.0 6,194 19.9 5,266 18.6 5,650 17.9
  60-69 9,054 28.3 8,824 28.6 9,084 29.2 8,436 29.8 9,951 31.6
  70-79 8,459 26.5 8,131 26.3 8,270 26.6 7,585 26.8 8,267 26.2
  ≥ 80 4,263 13.3 4,290 13.9 4,636 14.9 4,527 16.0 5,066 16.1
 Sex
  Male 21,531 67.3 20,983 67.9 20,989 67.5 18,983 67.1 20,970 66.5
  Female 10,445 32.7 9,905 32.1 10,114 32.5 9,299 32.9 10,547 33.5
 Insurance
  NHI beneficiaries 30,421 95.1 29,382 95.1 29,518 94.9 26,793 94.7 29,903 94.9
  MA recipients 1,555 4.9 1,506 4.9 1,585 5.1 1,489 5.3 1,614 5.1
Breast
 Total N
  No. of patients 25,981 26,874 28,361 28,327 32,541
 Age (yr)
  Age_Mean 54.0 11.7 54.2 11.7 54.5 11.7 54.8 11.8 55.2 12.0
 Age group (yr)
  < 20 6 0 1 0 5 0 6 0 2 0
  20-29 204 0.8 151 0.6 189 0.7 189 0.7 236 0.7
  30-39 2,046 7.9 2,055 7.6 2,135 7.5 2,010 7.1 2,116 6.5
  40-49 8,059 31.0 8,361 31.1 8,385 29.6 8,144 28.7 9,113 28.0
  50-59 7,964 30.7 8,249 30.7 8,614 30.4 8,621 30.4 9,793 30.1
  60-69 4,835 18.6 5,010 18.6 5,730 20.2 5,959 21.0 7,103 21.8
  70-79 2,183 8.4 2,282 8.5 2,503 8.8 2,527 8.9 3,047 9.4
  ≥ 80 684 2.6 765 2.8 800 2.8 871 3.1 1,131 3.5
 Sex
  Male 160 0.6 144 0.5 142 0.5 158 0.6 160 0.5
  Female 25,821 99.4 26,730 99.5 28,219 99.5 28,169 99.4 32,381 99.5
 Insurance
  NHI beneficiaries 25,079 96.5 25,990 96.7 27,450 96.8 27,396 96.7 31,445 96.6
  MA recipients 902 3.5 884 3.3 911 3.2 931 3.3 1,096 3.4
Prostate
 Total N
  No. of patients 13,706 15,587 17,461 17,889 19,581
 Age (yr)
  Age_Mean 71.5 8.5 71.5 8.5 71.6 8.4 72.1 8.4 72.1 8.5
 Age group (yr)
  < 20 2 0 1 0 - 0 1 0 1 0
  20-29 1 0 1 0 1 0 - 0 2 0
  30-39 8 0.1 7 0 9 0.1 4 0 8 0
  40-49 70 0.5 94 0.6 85 0.5 78 0.4 91 0.5
  50-59 1,111 8.1 1,199 7.7 1,236 7.1 1,190 6.7 1,198 6.1
  60-69 4,201 30.7 4,772 30.6 5,470 31.3 5,368 30.0 6,056 30.9
  70-79 5,969 43.6 6,797 43.6 7,552 43.3 7,713 43.1 8,270 42.2
  ≥ 80 2,344 17.1 2,716 17.4 3,108 17.8 3,535 19.8 3,955 20.2
 Sex
  Male 13,706 100 15,587 100 17,461 100 17,889 100 19,581 100
 Insurance
  NHI beneficiaries 13,131 95.8 14,955 95.9 16,749 95.9 17,102 95.6 18,652 95.3
  MA recipients 575 4.2 632 4.1 712 4.1 787 4.4 929 4.7

MA, medical aid; NHI, National Health Insurance; SD, standard deviation.