Disparities in Overall Survival Rates for Cancers across Income Levels in the Republic of Korea.

BACKGROUND: The overall survival rates among cancer patients have been improving. However, the increase in survival is not uniform across socioeconomic status. Thus, we investigated income disparities in the 5-year survival rate (5YSR) in cancer patients and the temporal trends. METHODS: This study used a national cancer cohort from 2002 to 2018 that was established by linking the Korea Central Cancer Registry and the National Health Insurance Service (NHIS) claim database to calculate the cancer survival rate by income level in the Republic of Korea. Survival data were available from 2002 onward, and the analysis was based on the actuarial method. We compared the survival of the earliest available 5-year period of 2002-2006 and the latest available 5-year period of 2014-2018, observing until 31 December 2021. Income level was classified into six categories: Medical Aid beneficiaries and five NHIS subtypes according to insurance premium. The slope index of inequality (SII) and relative index of inequality were used to measure absolute and relative differences in 5YSR by income, respectively. RESULTS: The 5YSR between the 2002-2006 and 2014-2018 periods for all cancers improved. A significant improvement in 5-year survival rates (5YSR) over the study period was observed in lung, liver, and stomach cancer. The SII of survival rates for lung (17.5, 95% confidence interval (CI) 7.0-28.1), liver (15.1, 95% CI 10.9-19.2), stomach (13.9, 95% CI 3.2-24.7), colorectal (11.4, 95% CI 0.9-22.0), and prostate (10.7, 95% CI 2.5-18.8) cancer was significantly higher, implying higher survival rates as income levels increased. The SII for lung, liver, and stomach cancer increased, while that of thyroid, breast, cervical, prostate, and colorectal cancer decreased over the study period. CONCLUSIONS: Although substantial improvement in the 5YSR was observed across cancer types and income levels from 2002 to 2018, this increase was not uniformly distributed across income levels. Our study revealed persistent income disparities in the survival of cancer patients, particularly for lung and liver cancer.

Trends in Cancer-screening Rates in Korea: Findings from the National Cancer Screening Survey, 2004-2023.

Purpose: This study aimed to report the overall national trends in the rates of cancer screening based on recommendations and provide insights into the changing trends of these rates across different demographics. Materials and Methods: This study used data from the Korean National Cancer Screening Survey (KNCSS), which surveys nationwide cancer-screening rates and includes 4,500 individuals meeting the Korean National Cancer Screening Program (NCSP) protocol age criteria. Cancer-screening rates were assessed using structured questionnaires; yearly trends were analyzed for both lifetime cancer-screening rates and rates of screening based on recommendations, and subgroup analyses were performed based on age and sex. Results: The rates of cancer screening based on recommendations showed significant increments: the stomach cancer-screening rate increased from 39.2% in 2004 to 77.5% in 2023 (3.50% per year), the liver cancer-screening rate increased from 20.0% to 48.8% (4.30% per year), and the colorectal cancer, increased from 19.9% to 70.7% (5.15% per year). The breast cancer-screening rate increased from 33.2% to 72.7% (2.88% per year), and the cervical cancer, increased from 58.3% to 70.2% (1.08% per year). Despite some differences, particularly in relation to sociodemographic factors, screening rates increased significantly for all cancer types. Conclusion: Cancer-screening rates in Korea increased consistently from 2004 to 2023, demonstrating the effectiveness of the national cancer-screening program. However, the increments in breast, cervical and lung cancer-screening rates were relatively lower, indicating the need for additional efforts and strategies.

Factors Associated With Continuous Use of a Cancer Education Metaverse Platform: Mixed Methods Study.

BACKGROUND: Early detection of cancer and provision of appropriate treatment can increase the cancer cure rate and reduce cancer-related deaths. Early detection requires improving the cancer screening quality of each medical institution and enhancing the capabilities of health professionals through tailored education in each field. However, during the COVID-19 pandemic, regional disparities in educational infrastructure emerged, and educational accessibility was restricted. The demand for remote cancer education services to address these issues has increased, and in this study, we considered medical metaverses as a potential means of meeting these needs. In 2022, we used Metaverse Educational Center, developed for the virtual training of health professionals, to train radiologic technologists remotely in mammography positioning. OBJECTIVE: This study aims to investigate the user experience of the Metaverse Educational Center subplatform and the factors associated with the intention for continuous use by focusing on cases of using the subplatform in a remote mammography positioning training project. METHODS: We conducted a multicenter, cross-sectional survey between July and December 2022. We performed a descriptive analysis to examine the Metaverse Educational Center user experience and a logistic regression analysis to clarify factors closely related to the intention to use the subplatform continuously. In addition, a supplementary open-ended question was used to obtain feedback from users to improve Metaverse Educational Center. RESULTS: Responses from 192 Korean participants (male participants: n=16, 8.3%; female participants: n=176, 91.7%) were analyzed. Most participants were satisfied with Metaverse Educational Center (178/192, 92.7%) and wanted to continue using the subplatform in the future (157/192, 81.8%). Less than half of the participants (85/192, 44.3%) had no difficulty in wearing the device. Logistic regression analysis results showed that intention for continuous use was associated with satisfaction (adjusted odds ratio 3.542, 95% CI 1.037-12.097; P=.04), immersion (adjusted odds ratio 2.803, 95% CI 1.201-6.539; P=.02), and no difficulty in wearing the device (adjusted odds ratio 2.020, 95% CI 1.004-4.062; P=.049). However, intention for continuous use was not associated with interest (adjusted odds ratio 0.736, 95% CI 0.303-1.789; P=.50) or perceived ease of use (adjusted odds ratio 1.284, 95% CI 0.614-2.685; P=.51). According to the qualitative feedback, Metaverse Educational Center was useful in cancer education, but the experience of wearing the device and the types and qualities of the content still need to be improved. CONCLUSIONS: Our results demonstrate the positive user experience of Metaverse Educational Center by focusing on cases of using the subplatform in a remote mammography positioning training project. Our results also suggest that improving users' satisfaction and immersion and ensuring the lack of difficulty in wearing the device may enhance their intention for continuous use of the subplatform.

Socioeconomic Disparities in Six Common Cancer Survival Rates in South Korea: Population-Wide Retrospective Cohort Study.

Background: In South Korea, the cancer incidence rate has increased by 56.5% from 2001 to 2021. Nevertheless, the 5-year cancer survival rate from 2017 to 2021 increased by 17.9% compared with that from 2001 to 2005. Cancer survival rates tend to decline with lower socioeconomic status, and variations exist in the survival rates among different cancer types. Analyzing socioeconomic patterns in the survival of patients with cancer can help identify high-risk groups and ensure that they benefit from interventions. Objective: The aim of this study was to analyze differences in survival rates among patients diagnosed with six types of cancer-stomach, colorectal, liver, breast, cervical, and lung cancers-based on socioeconomic status using Korean nationwide data. Methods: This study used the Korea Central Cancer Registry database linked to the National Health Information Database to follow up with patients diagnosed with cancer between 2014 and 2018 until December 31, 2021. Kaplan-Meier curves stratified by income status were generated, and log-rank tests were conducted for each cancer type to assess statistical significance. Hazard ratios with 95% CIs for any cause of overall survival were calculated using Cox proportional hazards regression models with the time since diagnosis. Results: The survival rates for the six different types of cancer were as follows: stomach cancer, 69.6% (96,404/138,462); colorectal cancer, 66.6% (83,406/125,156); liver cancer, 33.7% (23,860/70,712); lung cancer, 30.4% (33,203/109,116); breast cancer, 91.5% (90,730/99,159); and cervical cancer, 78% (12,930/16,580). When comparing the medical aid group to the highest income group, the hazard ratios were 1.72 (95% CI 1.66-1.79) for stomach cancer, 1.60 (95% CI 1.54-1.56) for colorectal cancer, 1.51 (95% CI 1.45-1.56) for liver cancer, 1.56 (95% CI 1.51-1.59) for lung cancer, 2.19 (95% CI 2.01-2.38) for breast cancer, and 1.65 (95% CI 1.46-1.87) for cervical cancer. A higher deprivation index and advanced diagnostic stage were associated with an increased risk of mortality. Conclusions: Socioeconomic status significantly mediates disparities in cancer survival in several cancer types. This effect is particularly pronounced in less fatal cancers such as breast cancer. Therefore, considering the type of cancer and socioeconomic factors, social and medical interventions such as early cancer detection and appropriate treatment are necessary for vulnerable populations.

Exploring age-standardized cancer incidence rates and regional disparities: A retrospective cohort study of 8 major cancers in South Korea.

BACKGROUND: We analyzed trends in cancer incidence and regional disparities of eight major types of cancer in Korea. METHODS: This retrospective cohort study used the data of 17 cities/provinces from the Korea Central Cancer Registry (1999-2020) in South Korea. Age-standardized incidence rates (per 100,000 person-years), between-group variance (per 100,000 person-years)2, and annual percentage changes ( %) were calculated for the eight most common malignancies. Joinpoint regression was utilized to identify the points at which significant changes occur in cancer incidence or regional disparity trends over time to characterize these trends. RESULTS: The incidence of stomach cancer decreased as regional disparity decreased and that of colorectal cancer initially increased but recently declined, showing fluctuations in regional disparity. The incidence and regional disparity in liver cancer decreased. The incidence of lung cancer remained stable, with reduced regional disparities. The incidence of breast cancer rose with increasing regional disparity, whereas the incidence of cervical cancer decreased, accompanied by decreased regional disparity. A significant increase in prostate cancer was found, with initially reduced regional disparities but later showed a resurgence. The incidence of thyroid cancer fluctuated alongside variations in regional disparities. CONCLUSION: This study revealed cancer incidence and regional variations in each cancer type in Korea. More studies are needed to understand the underlying factors and potential interventions for reducing cancer incidence and addressing regional disparity.

Geographic Progression of Infant Respiratory Syncytial Virus Associated Bronchiolitis Across the United States Before and Since the Onset of COVID-19: Results From Four Health Systems, 2015-2023.

BACKGROUND: Respiratory syncytial virus (RSV) is a substantial cause of infant morbidity and mortality due to seasonal peaks of bronchiolitis across the United States. Clinical and viral surveillance plays a pivotal role in helping hospital systems prepare for expected surges in RSV bronchiolitis. Existing surveillance efforts have shown a geographic pattern of RSV positivity across the United States, with cases typically starting in the southeast and spreading north and west. Public health measures implemented due to the COVID-19 pandemic disrupted viral transmission across the nation and altered the expected seasonality of RSV. The impact of these changes on the geographic progression of infant RSV bronchiolitis across the United States has not been described. METHODS: Here, we used clinical and viral surveillance data from four health care systems located in different regions of the United States to describe the geographic progression of infant RSV bronchiolitis across the country from 2015 to 2023. RESULTS: Prior to widespread circulation of SARS-CoV-2, infant RSV bronchiolitis followed an established geographic pattern associated with seasonal epidemics originating in Florida and spreading north (North Carolina and New York) and later westward (Nevada). Although public health and social measures implemented during the COVID-19 pandemic disrupted the seasonality of RSV disease, infant RSV bronchiolitis epidemics progressed across the nation in a pattern identical to the prepandemic era. CONCLUSIONS: Our findings highlight the importance of ongoing clinical and viral surveillance to optimally track the onset of RSV epidemics and allow health care systems to prepare for expected RSV bronchiolitis surges.

Healthcare Utilization Among Infants Covered by Medicaid and Newly Diagnosed With Respiratory Syncytial Virus.

Background: Infants covered by Medicaid have higher respiratory syncytial virus (RSV) hospitalization rates than those with commercial insurance, but findings are limited to the inpatient setting. This birth cohort study describes healthcare encounters for RSV across all settings among infants covered by Medicaid and the Children's Health Insurance Program. Methods: Medicaid claims for infants born and residing in Arizona (AZ), California (CA), Florida (FL), Michigan (MI), North Carolina (NC), New York (NY), and Texas (TX) were analyzed for first diagnosis of RSV in 2016-2018 using International Classification of Diseases, Tenth Revision codes. Encounters on the day of first diagnosis were examined by setting in 7 states and by setting and race in CA, FL, and NC. Results: A total of 80 945 infants were diagnosed with RSV in 7 states in 2016-2018. The highest encounter rates for first RSV diagnosis were in the emergency department (ED) in 5 states (11.0-33.4 per 1000 in AZ, CA, FL, MI, and NY) and outpatient setting in 2 states (54.8 and 68.5 per 1000 in TX and NC). Significantly higher outpatient encounter rates were found in CA and NC for White infants compared to non-White infants. In NC, ED encounter rates were significantly higher for non-White infants than White infants, whereas in CA, the rates were comparable. In these 2 states, hospitalization rates were similar across groups. In FL, compared with White infants, non-White infants had significantly higher encounter rates in each setting on the day of first RSV diagnosis. Conclusions: This is the first study to describe the burden of RSV by setting and race. Medicaid infants who are newly diagnosed with RSV have the highest burden in ED and outpatient settings.

Trends in RSV testing patterns among infants presenting with bronchiolitis: Results from four United States health systems, 2015-2023.

BACKGROUND: Bronchiolitis due to respiratory syncytial virus (RSV) is the leading cause of hospitalization among American infants. The overall burden of RSV among infants has been historically under-estimated due to variable testing practices, particularly in the outpatient setting. Universal masking and social distancing implemented during the coronavirus disease 2019 (COVID-19) pandemic altered RSV seasonality, however potential consequences on RSV testing practices across different healthcare settings and sociodemographic groups have not been described. Variable testing practices could also affect accurate assessment of the effects of two recently approved RSV preventative agents targeting infants. METHODS: Utilizing real-time clinical and viral surveillance, we examined RSV testing practices among infants with bronchiolitis within four United States healthcare systems across different healthcare settings and sociodemographic groups pre- and post-COVID-19. RESULTS: RSV testing among infants with bronchiolitis increased since 2015 within each healthcare system across all healthcare settings and sociodemographic groups, with a more dramatic increase since the COVID-19 pandemic. Outpatient testing remained disproportionately low compared to hospital-based testing, although there were no major differences in testing frequency among sociodemographic groups in either setting. CONCLUSIONS: Although RSV testing increased among infants with bronchiolitis, relatively low outpatient testing rates remain a key barrier to accurate RSV surveillance.

Association between Endoscopist Volume and Interval Cancers after Colonoscopy: Results from the National Colorectal Cancer Screening Program in Korea.

Purpose: The rate of interval colorectal cancer (iCRC) is now accepted as a key performance indicator of organized colorectal cancer (CRC) screening programs. We aimed to examine the association between endoscopist volumes and the rate of iCRC among individuals with a positive fecal immunochemical test (FIT) within a nationwide population-based CRC screening program. Materials and Methods: Individuals aged ≥50 years who underwent colonoscopy after a positive FIT from January 1, 2019 until December 31, 2020 in the Korean National Cancer Screening Program (KNCSP) were enrolled. We converted the data into per-endoscopist screening results, calculated the iCRC rates per endoscopist, and compared them to the previous year's annual volume that was divided into five groups (V1, 1-9; V2, 10-29; V3, 30-59; V4, 60-119; V5, ≥120). Results: A total of 10,412 endoscopists performed 216,907 colonoscopies. Overall, the average rate of iCRC per endoscopist was 8.46 per 1,000 examinations. Compared with the group with the highest volume (V5 group), the rate of iCRC was 2.21 times higher in the V1 group. Similar trends were observed in the other groups (V2: Relative risks [RR], 2.15; 95% Confidence Interval [CI], 1.57-2.94; V3: RR, 1.56, 95% CI, 1.15-2.13; V4: RR, 1.18; 95% CI, 0.83-1.67). Conclusion: The findings emphasize that endoscopists with lower procedure volumes have higher risks of interval cancer being missed or undetected. To maximize the preventative impact of colonoscopy for colorectal cancer, this issue should be addressed by monitoring endoscopist volumes and variations in performances.

A meta-analysis of efficacy and safety data from head-to-head first-line trials of epidermal growth factor receptor inhibitors versus bevacizumab in adult patients with RAS wild-type metastatic colorectal cancer by sidedness.

The first-line treatment choice of EGFRIs plus doublet chemotherapy vs. bevacizumab plus doublet chemotherapy remains a topic of interest for patients with left-sided RAS WT mCRC. We conducted a systematic literature review and meta-analysis of clinical trial data published between 2015 and 2024. We evaluated the relative efficacy and safety of first-line EGFRIs plus doublet chemotherapy (FOLFIRI or FOLFOX) vs. bevacizumab plus doublet chemotherapy for patients with RAS WT left-sided mCRC, as well as in all- and right-sided tumors. We identified eight trials with 2624 patients. Five trials reported outcomes by tumor sidedness. In the left-sided population, overall survival (OS) (Hazard Ratio (HR) = 0.80, 95% Confidence Interval (CI): 0.71-0.90) and objective response rate (ORR) (Odds ratio [OR]=1.61, 95% CI: 1.30-1.99) favored EGFRI plus chemotherapy, while no statistically significant differences were observed for progression-free survival (PFS) (HR=0.93, 95% CI: 0.84-1.04) or resection rate (RR). Similar results were found in the all-sided population. In the right-sided population, PFS favored bevacizumab plus chemotherapy (HR=1.45, 95% CI: 1.19-1.78), while no statistically significant differences were observed for OS (HR=1.17, 95% CI: 0.95-1.44), ORR (OR=0.99, 95% CI: 0.69-1.41), and RR. Early tumor shrinkage in the all-sided population favored EGFRI plus chemotherapy (OR=1.72; 95% CI: 1.36-2.17); limited data precluded evaluation by sidedness. Safety was available in 6 trials for all-sided tumors and 1 trial for left-sided tumors, each demonstrating typical class-specific adverse events. This most comprehensive meta-analysis indicates a benefit for first-line EGFRI plus chemotherapy over bevacizumab plus chemotherapy in patients with left-sided RAS WT mCRC.

Cost-Utility Analysis for Colorectal Cancer Screening According to the Initiating Age of National Cancer Screening Program in Korea.

BACKGROUND: This study aimed to identify the most cost-effective strategy for colorectal cancer screening using the fecal immunochemical test (FIT), focusing on screening initiation age in Korea. METHODS: We designed Markov simulation models targeting individuals aged 40 years or older. Twelve strategies combining screening initiation ages (40, 45, or 50 years old), termination ages (80 or no limit), and intervals (1 or 2 years) were modeled, and the most cost-effective strategy was selected. The robustness of the results was confirmed using one-way and probabilistic sensitivity analyses. Furthermore, the cost-effectiveness of the qualitative and quantitative FIT methods was verified using scenario analysis. RESULTS: The 2-year interval strategy with a screening age range of 45-80 years was the most cost-effective (incremental cost-utility ratio = KRW 7,281,646/quality adjusted life years). The most sensitive variables in the results were transition rate from advanced adenoma to local cancer and discount rate. The uncertainty in the model was substantially low. Moreover, strategies starting at the age of 40 years were also cost-effective but considered suboptimal. The scenario analysis showed that there was no significant difference in cost-effectiveness between strategies with various relative screening ratio of quantitative and qualitative method. CONCLUSION: The screening method for advancing the initiation age, as presented in the 2015 revised national screening recommendations, was superior regarding cost-effectiveness. This study provides a new paradigm for the development of a national cancer screening system in Korea, which can be utilized as a scientific basis for economic evaluations.

The effect of bovine dairy products and their components on the incidence and natural history of infection: a systematic literature review.

BACKGROUND: Dairy products and their components may impact immune function, although the current evidence base has some research gaps. As part of a larger systematic literature review of dairy products/components (including probiotics, dairy proteins, and dairy fats) and immune function, we identified the available epidemiologic research on the impact of dairy products/components on incidence and natural history of infectious diseases. METHODS: PubMed and Embase databases were systematically searched through May 2022 to identify eligible studies using pre-defined Population, Intervention, Comparator, Outcomes, and Study design criteria. Herein, we focused on describing the impacts of dairy product/component on infectious disease outcomes, including the effect on leukocyte and cytokine response in humans. Risk of bias assessment was performed using the Academy of Nutrition and Dietetics Quality Criteria Checklist. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. RESULTS: Among 9,832 studies identified from the larger literature search, 133 relevant publications from 128 studies reported on dairy product/component and infectious disease outcomes. Few studies are available on the impact of non-fermented milk and traditional yogurt on infectious disease. Evidence was identified to suggest milk and yogurt drinks fermented with Lactobacillus strains reduce the risk and burden of common infectious diseases (CIDs), although the findings are mixed and difficult to reconcile due to heterogenous study populations, bacterial strains, and study methods. Few studies are available on the impact of dairy products/components on the natural history of infection, with the available findings indicating probiotics may both improve gastrointestinal symptoms among HIV-infected persons and help eradicate and alleviate the symptoms of Heliobacter (H.) pylori. The available evidence also suggests lactoferrin may reduce the virological burden of COVID-19 and hepatitis C virus. No consistent changes in leukocytes or cytokine production were observed for any type of dairy product or their components, but probiotics appeared to enhance natural killer cell levels/activity and the phagocytic process. CONCLUSIONS: Dairy products, particularly those with added probiotics, may represent an easily accessible nutritional intervention to prevent and improve the course of infectious diseases. This review highlights the need for additional research in this potentially impactful area. PROSPERO REGISTRATION: CRD42022333780.

Overview of global real-world data sources for pediatric pharmacoepidemiologic research.

PURPOSE: Given limited information available on real-world data (RWD) sources with pediatric populations, this study describes features of globally available RWD sources for pediatric pharmacoepidemiologic research. METHODS: An online questionnaire about pediatric RWD sources and their attributes and capabilities was completed by members and affiliates of the International Society for Pharmacoepidemiology and representatives of nominated databases. All responses were verified by database representatives and summarized. RESULTS: Of 93 RWD sources identified, 55 unique pediatric RWD sources were verified, including data from Europe (47%), United States (38%), multiregion (7%), Asia-Pacific (5%), and South America (2%). Most databases had nationwide coverage (82%), contained electronic health/medical records (47%) and/or administrative claims data (42%) and were linkable to other databases (65%). Most (71%) had limited outside access (e.g., by approval or through local collaborators); only 10 (18%) databases were publicly available. Six databases (11%) reported having >20 million pediatric observations. Most (91%) included children of all ages (birth until 18th birthday) and contained outpatient medication data (93%), while half (49%) contained inpatient medication data. Many databases captured vaccine information for children (71%), and one-third had regularly updated data on pediatric height (31%) and weight (33%). Other pediatric data attributes captured include diagnoses and comorbidities (89%), lab results (58%), vital signs (55%), devices (55%), imaging results (42%), narrative patient histories (35%), and genetic/biomarker data (22%). CONCLUSIONS: This study provides an overview with key details about diverse databases that allow researchers to identify fit-for-purpose RWD sources suitable for pediatric pharmacoepidemiologic research.

The Effect of Nationwide Organized Cancer Screening Programs on Gastric Cancer Mortality: A Synthetic Control Study.

BACKGROUND & AIMS: Nationwide organized gastric cancer (GC) screening programs have been running for decades in South Korea and Japan. This study conducted a quasi-experimental analysis to assess the population impact of these programs on GC mortality. METHODS: We used the flexible synthetic control method (SCM) to estimate the effect of the screening programs on age-standardized GC mortality and other upper gastrointestinal (UGI) diseases (esophageal cancer and peptic ulcer) among people aged ≥40 years. World Health Organization mortality data and country-level covariates from the World Bank and the Global Burden of Diseases study were used for the analyses. We compared postintervention trends in outcome with the counterfactual trend of the synthetic control and estimated average postintervention rate ratios (RRs) with associated 95% confidence intervals (CIs). A series of sensitivity analyses were conducted. RESULTS: The preintervention fits were acceptable for the analyses of South Korea and Japan's GC mortality but poor for Japan's other UGI disease mortality. The average postintervention RRs were 0.83 (95% CI, 0.71-0.96) for GC mortality and 0.72 (95% CI, 0.57-0.90) for other UGI disease mortality in South Korea. The RR reached 0.59 by the 15th year after the initiation of nationwide screening. For Japan, the average RRs were 0.97 (95% CI, 0.88-1.07) for GC mortality and 0.93 (95% CI, 0.68-1.28) for other UGI disease mortality. Sensitivity analysis reveals the result for Japan may potentially be biased. CONCLUSIONS: South Korea's nationwide GC screening has apparent benefits, whereas the Japanese program's effectiveness is uncertain. The experiences of South Korea and Japan could serve as a reference for other countries.

The Impact of Neighborhood Deprivation on the Survival Rates of Patients with Cancer in Korea.

The objective of this study is to investigate the correlation between the neighborhood deprivation index and survival rates of cancer patients in Korea. In this study, 5-year age-standardized survival rates of patients with cancer were determined using the National Cancer Cohort from 2014 to 2018 in Korea. The primary cancer sites were the stomach, colorectum, liver, lung, breast, cervix, prostate, and thyroid. Disparities were measured, and their impact on the overall survival rates was assessed using the Korean version of the Neighborhood Deprivation Index. Pearson's correlation coefficient was calculated to determine the strength of the correlation. The study cohort comprised 726,665 patients with cancer, of whom 50.7% were male. The predominant primary cancer sites were the stomach (n = 138,462), colorectum (n = 125,156), and thyroid gland (n = 120,886). Urban residents showed better survival outcomes than those situated in rural areas. The most deprived quartile had the lowest survival rate, while the least deprived quartile had the highest (p < 0.001). Most cancer types revealed significant correlations between neighborhood deprivation and 5-year age-standardized overall survival, with lung cancer showing the most substantial negative correlation (r = -0.510), followed by prostate cancer (r = -0.438). However, thyroid cancer showed only a marginal correlation (p = 0.069). The results of this study suggested that neighborhood deprivation is closely linked to disparities in overall survival across various types of cancer. A substantial negative correlation between the neighborhood deprivation index and all-cause mortality for lung and prostate cancer, as compared to breast and cervical cancers covered by the National Cancer Screening Program, may reinforce the need to address healthcare access and improve the early detection of cancer in socioeconomically deprived neighborhoods.

Disparities in Cancer Incidence across Income Levels in South Korea.

BACKGROUND: Recent nationwide studies of disparities in cancer incidence by income are scarce in Korea. This study investigated such disparities in cancer incidence and the stage at cancer diagnosis across income groups in Korea. METHODS: This study utilized data from a national cancer database, specifically focusing on cases recorded in the year 2018. Income levels were categorized into quintiles according to the insurance premium paid in addition to the Medicaid benefit. The slope index of inequality (SII) and relative index of inequality (RII) were used to measure absolute and relative differences in cancer incidence by income. A multivariable logistic regression was performed to estimate the risk of a distant stage at cancer diagnosis. RESULTS: The total number of cases of incident cancer was 223,371 (men: 116,320, women: 107,051) with shares of the total of 29.5% (5Q), 20.4% (4Q), 16.0% (3Q), 13.5% (2Q), 15.6% (1Q), and 5% (Medicaid). The most common cancer type was thyroid cancer, followed by gastric and colorectal cancers. The age-standardized incidence rate for all cancers was lowest in the highest income group, but the SII was not statistically significant (SII: -35.7), and the RII was -0.07. Colorectal and cervical cancers had lower incidence rates for higher income groups, while thyroid and prostate cancers had higher incidence rates for higher income groups. The odds ratio for a distant stage at diagnosis for all cancers increased for lower income groups relative to 5Q. CONCLUSIONS: Disparities in cancer incidence in a Korean population differed by cancer type, and lower income was a significant predictor of a distant stage at diagnosis for cancers overall. These results emphasize the need for further study of the underlying causes of disparities in cancer incidence and the stage at diagnosis, as well as the need for interventions to mitigate these disparities.

A Web-Based Decision Aid for Informed Prostate Cancer Screening: Development and Pilot Evaluation.

BACKGROUND: Prostate-specific antigen-based routine screening is not recommended for the general population due to conflicting results with mortality reduction. We aimed to develop a web-based decision aid (DA) for informed decision making for prostate cancer screening. METHODS: Using the International Patient Decision Aid Standards (IPDAS) development process model, we developed our DA based on patient and clinician interviews and multidisciplinary expert discussions. The prototype consisted of predicting individual prostate cancer risk and informed decision-making, including knowledge, risk and benefit, cost, personal value, and decision making. We conducted a pilot study on 101 healthy men, evaluating the effectiveness of DA by measuring knowledge, attitude, and intention to screen before and after using the DA, as well as decisional conflict and usefulness after using the DA. RESULTS: Of the 101 participants (median age 60 [50-69] years), 84% had not undergone screening for prostate cancer in the past two years. After using the DA, knowledge on prostate cancer screening increased (mean score [of 10] before versus after: 6.85 ± 1.03 versus 7.57 ± 1.25; P < 0.001), and intention to not screen increased from 27.7% to 51.5% (P < 0.001), but attitude toward screening did not change (P = 0.564). After use of the DA, 79 participants reported no decisional conflict, and the usefulness score was high (mean score [of 100] 77.35 ± 7.69), with 85% of participants reporting that the DA helped with decision making. CONCLUSION: Our web-based DA yielded increased knowledge, decreased screening intention, and high perceived usefulness. These findings indicate potential clinical relevance, especially among younger individuals.

Cluster of lifestyle risk factors for stomach cancer and screening behaviors among Korean adults.

This study aimed to investigate clustering patterns of lifestyle risk factors for stomach cancer and examine the association of risk factor clusters with stomach cancer screening adherence. Data from the 2019 Korean National Cancer Screening Survey, an annual cross-sectional nationwide survey, were used. The study population included 3539 adults aged 40-74 years with no history of cancer. Six stomach cancer risk factors, including smoking, drinking, physical inactivity, obesity, meat intake, and salted food intake, as well as stomach cancer screening behaviors, were assessed. The most frequent risk factor for stomach cancer was physical inactivity, followed by smoking in males and high salted food intake in females. Compared with participants subjects with no risk factors, those with three or more risk factors were less likely to adhere to screening guidelines (males: adjusted odds ratio [aOR] = 0.35, 95% confidence interval [CI] 0.23-0.53; females: aOR = 0.32, 95% CI 0.21-0.48). Our findings indicate a disparity in stomach cancer screening, such that those with more risk factors are less likely to get screened. Increasing public awareness, providing behavioral counseling, and targeting high-risk populations for screening interventions are critical for promoting cancer screening adherence and reducing the disparity in cancer screening.

Socioeconomic inequality in organized and opportunistic screening for gastric cancer: results from the Korean National Cancer Screening Survey 2009-2022.

Objectives: This study aimed to evaluate the socioeconomic inequality in gastric cancer (GC) screening in Korea. Socioeconomic inequality was assessed using both organized and opportunistic screening according to income and educational level. Methods: GC screening data were obtained from the 2009-2022 Korean National Cancer Screening Survey. The final analysis included 47,163 cancer-free men and women. The weighted cancer screening rate was estimated using joinpoint regression. The inequality indices were measured in terms of both the absolute slope index of inequality (SII) and the relative index of inequality (RII) using the Poisson regression model. Results: The organized screening rate for GC increased from 38.2% in 2009 to 70.8% in 2022, whereas the opportunistic screening rate decreased from 18.8 to 4.5%. Regarding educational inequality, a negative SII value was observed [-3.5, 95% confidence interval (CI), -7.63-0.83%] in organized screening, while a positive SII (9.30%; 95% CI, 6.69-11.91%) and RII (1.98%; 95% CI, 1.59-2.46) were observed in opportunistic screening. Furthermore, income inequality was not found in organized GC screening; however, overall SII and RII for opportunistic screening were 7.72% (95% CI, 5.39-10.5) and 1.61 (95% CI, 1.42-1.81), respectively. Conclusion: Organized screening rates have grown gradually over time and account for the majority of GC screenings in South Korea. While no socioeconomic inequalities were found in organized screening, significant socioeconomic inequalities were found in opportunistic screening.

Socioeconomic differences in the perception of inequalities in healthcare utilization and health in South Korea.

This study investigated the lay perception of inequalities in society, healthcare utilization, and health in Korea. We also examined the association between socioeconomic status (SES) and perception of inequalities. Data from an online survey on the perception of health and healthcare inequalities related to cancer conducted between October 19, 2021, and November 12, 2021, were used. Data of 3,769 participants aged 20 to 74 years from 17 provinces were analyzed. We examined the perceived level of inequalities according to SES or residential area using frequency analysis, a t-test or analysis of variance (ANOVA), multiple linear regression analysis, and multiple logistic regression analysis. The mean score for perception of social inequality was 5.99 [Standard Deviation (SD) = 1.95] and that for perception of healthcare utilization inequality was 4.75 (SD = 1.96). The perception rate of health inequality according to SES and residential area was approximately 59 % and 61 %, respectively. Higher the income level, lower the level of perception of social inequalities ß = -0.22, p < 0.01). Higher the education level, higher the level of perception of healthcare utilization inequalities (ß = 0.21, p < 0.01). Higher the education level, higher the level of perception of health inequalities according to SES or residential area [adjusted odds ratio (aOR): 2.33 (95 % CI: 1.48, 3.66); aOR: 2.73 (95 % CI: 1.73, 4.31)]. Socioeconomic inequalities were observed in the perception of inequalities in healthcare utilization and health. Policymakers should establish policies to bridge the gap between perceived healthcare utilization inequalities and health inequalities. Future research should investigate the perception of healthcare utilization and health inequalities.