Effectiveness of COVID-19 vaccines against severe outcomes in cancer patients: Real-world evidence from self-controlled risk interval and retrospective cohort studies.

BACKGROUND: The effectiveness of COVID-19 vaccines is generally reduced in cancer patients compared to the general population. However, there are only a few studies that compare the relative risk of breakthrough infections and severe COVID-19 outcomes in fully vaccinated cancer patients versus their unvaccinated counterparts. METHODS: To assess the effectiveness of COVID-19 vaccines in cancer patients, we employed (1) a self-controlled risk interval (SCRI) design, and (2) a retrospective matched cohort design. A SCRI design was used to compare the risk of breakthrough infection in vaccinated cancer patients during the period immediately following vaccination ("control window") and the period in which immunity is achieved ("exposure windows"). The retrospective matched cohort design was used to compare the risk of severe COVID-19 outcomes between vaccinated and unvaccinated cancer patients. For both studies, data were extracted from the Korea Disease Control and Prevention Agency-COVID-19-National Health Insurance Service cohort, including demographics, medical history, and vaccination records of all individuals confirmed with COVID-19. We used conditional Poisson regression to calculate the incidence rate ratio (IRR) for breakthrough infection and Cox regression to estimate the hazard ratio (HR) for severe outcomes. RESULTS: Of 14,448 cancer patients diagnosed with COVID-19 between October 2020 and December 2021, a total of 217 and 3996 cancer patients were included in the SCRI and cohort study respectively. While the risk of breakthrough infections, measured by the incidence rate in the control and exposure windows, did not show statistically significant difference in vaccinated cancer patients (IRR=0.88, 95% CI: 0.64-1.22), the risk of severe COVID-19 outcomes was significantly lower in vaccinated cancer patients compared to those unvaccinated (HR=0.27, 95% CI: 0.22-0.34). CONCLUSION: COVID-19 vaccines significantly reduce the risk of severe outcomes in cancer patients, though their efficacy against breakthrough infections is less evident.

Increased Risk of New-Onset Parkinson's Disease Following a Diagnosis of Retinal Vascular Occlusion: A 14-Year Cohort Study.

BACKGROUND: Although the role of the vascular component in the pathophysiology of Parkinson's disease is widely accepted and retinal vascular abnormalities are commonly observed in Parkinson's disease patients, evidence connecting retinal vascular disorders with the risk of developing Parkinson's disease is limited. We aimed to investigate the association between retinal vascular occlusion (RVO) and the risk of developing Parkinson's disease in people over 60 years using a nationwide cohort. METHODS: From the 14-year South Korean National Health Insurance Service-Senior cohort, 11 210 incident RVO patients and 11 210 propensity scores, risk-matched controls were included. The incidence of Parkinson's disease was estimated with a Poisson regression. A Cox proportional hazards regression model was used to investigate the associations between RVO and the risk of Parkinson's disease. RESULTS: The incidence of Parkinson's disease was 664.4 cases per 100 000 person-years (95% confidence interval [CI], 599.7-736.0) in the RVO cohort. Individuals with RVO had an increased incidence of Parkinson's disease (hazard ratio [HR], 1.28; 95% CI: 1.10-1.49). Increased PD risk was predominantly observed in retinal artery occlusion patients (HR, 1.53; 95% CI: 1.11-2.12), male patients (HR, 1.67; 95% CI: 1.29-2.17), and 5 years after diagnosis (HR, 1.46; 95% CI: 1.10-1.93). CONCLUSIONS: Our findings suggest that a common pathophysiological pathway, such as vasculature changes, may exist between RVO and Parkinson's disease. RVO may be one of the risk factors associated with future development of Parkinson's disease. The nature of this association warrants further investigation.

Estimating the Epidemic Size of Superspreading Coronavirus Outbreaks in Real Time: Quantitative Study.

BACKGROUND: Novel coronaviruses have emerged and caused major epidemics and pandemics in the past 2 decades, including SARS-CoV-1, MERS-CoV, and SARS-CoV-2, which led to the current COVID-19 pandemic. These coronaviruses are marked by their potential to produce disproportionally large transmission clusters from superspreading events (SSEs). As prompt action is crucial to contain and mitigate SSEs, real-time epidemic size estimation could characterize the transmission heterogeneity and inform timely implementation of control measures. OBJECTIVE: This study aimed to estimate the epidemic size of SSEs to inform effective surveillance and rapid mitigation responses. METHODS: We developed a statistical framework based on back-calculation to estimate the epidemic size of ongoing coronavirus SSEs. We first validated the framework in simulated scenarios with the epidemiological characteristics of SARS, MERS, and COVID-19 SSEs. As case studies, we retrospectively applied the framework to the Amoy Gardens SARS outbreak in Hong Kong in 2003, a series of nosocomial MERS outbreaks in South Korea in 2015, and 2 COVID-19 outbreaks originating from restaurants in Hong Kong in 2020. RESULTS: The accuracy and precision of the estimation of epidemic size of SSEs improved with longer observation time; larger SSE size; and more accurate prior information about the epidemiological characteristics, such as the distribution of the incubation period and the distribution of the onset-to-confirmation delay. By retrospectively applying the framework, we found that the 95% credible interval of the estimates contained the true epidemic size after 37% of cases were reported in the Amoy Garden SARS SSE in Hong Kong, 41% to 62% of cases were observed in the 3 nosocomial MERS SSEs in South Korea, and 76% to 86% of cases were confirmed in the 2 COVID-19 SSEs in Hong Kong. CONCLUSIONS: Our framework can be readily integrated into coronavirus surveillance systems to enhance situation awareness of ongoing SSEs.

Association between Sudden Sensorineural Hearing Loss and the Risk of Cardio Cerebrovascular Disease.

OBJECTIVES: This study investigated the association between sudden sensorineural hearing loss (SSNHL) and the risk of cardio-cerebrovascular disease (CCVD) among older adults in South Korea. METHODS: Data from 38,426 patients in the Korean National Health Insurance Service-Senior Cohort from 2002 to 2019 were collected. The risk of CCVD includes both stroke and acute myocardial infarction. Propensity score matching (1:1) was used to identify pairs of individuals with and without SSNHL (n = 19,213 for cases and controls). Cox proportional hazards regression models were used to analyze the associations between variables. RESULTS: Patients with SSNHL had a higher risk of CCVD (hazard ratio [HR] = 1.17, 95% confidence interval [CI] = 1.11-1.24) compared to those without. The risk of CCVD was higher among those who experienced a stroke than those who did not (HR = 1.17 95% CI = 1.10-1.25). Compared to their matched controls, patients with SSNHL were 1.69 times (HR = 1.69 CI = 1.46-1.94) more likely to have CCVD during the first 12 months of the follow-up period. CONCLUSION: Older patients with SSNHL are at an increased risk of CCVD. Hence, a more attentive approach featuring aggressive monitoring of patients with SSNHL is required to lessen their risk of CCVD. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2372-2376, 2024.

Increased Risk of Dementia Following a Diagnosis of Hearing Impairment: A South Korean Nationwide Cohort Study.

BACKGROUND: Among the older adults, hearing impairment is a common problem and may contribute to dementia. OBJECTIVE: Therefore, we aimed to examine the association between hearing impairment and the risk of dementia among older adults in South Korea. METHODS: Using the Korean National Health Insurance Service-Senior Cohort from 2005 to 2019, we collected data of 44,728 patients. Hearing impairment was determined using the national disability registry. Propensity score matching (1:1) was performed to match patients with and without hearing impairment (case: 22,364, control: 22,364). A Cox proportional hazards regression model was built to analyze the association between hearing impairment and dementia. RESULTS: Patients with hearing impairment had a higher risk of dementia than those without hearing impairment (hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.23-1.34). Assessing the degree of disability, both severe (HR = 1.25, 95% CI = 1.16-1.35) and mild conditions (HR = 1.29, 95% CI = 1.23-1.35) had an increased risk of dementia, respectively. CONCLUSIONS: Older patients with hearing impairment exhibit an increased risk of dementia, thereby warranting a new approach to dementia care among these patients regardless of the degree of hearing impairment.

Uncertainty and Irreproducibility of Triboelectricity Based on Interface Mechanochemistry.

Triboelectrification mechanism is still not understood, despite centuries of investigations. Here, we propose a model showing that mechanochemistry is key to elucidate triboelectrification fundamental properties. Studying contact between gold and silicate glasses, we observe that the experimental triboelectric output is subject to large variations and polarity inversions. First principles analysis shows that electronic transfer is activated by mechanochemistry and the tribopolarity is determined by the termination exposed to contact, depending on the material composition, which can result in different charging at the macroscale. The electron transfer mechanism is driven by the interface barrier dynamics, regulated by mechanical forces. The model provides a unified framework to explain several experimental observations, including the systematic variations in the triboelectric output and the mixed positive-negative "mosaic" charging patterns, and paves the way to the theoretical prediction of the triboelectric properties.

Impact of Coinsurance Reduction Policy on Healthcare Utilization Among Children Under 15.

BACKGROUND: On October 1, 2017, a new coinsurance reduction policy for children under 15 was introduced to minimize the lack of inpatient medical services for economic reasons and secure children's access to medical care. METHODS: This study analyzes the effect of this coinsurance reduction policy on healthcare utilization using data from the National Health Insurance Service-National Sample Cohort between 2015 and 2019. Groups were classified by 3 case groups and a control group according to age. The dependent variables were inpatient cost, admission, length of hospitalization, outpatient cost and visit, and total cost. The difference-in-differences method was used to examine changes in healthcare utilization among the case and control groups after policy implementation. RESULTS: Children of the age group 1-5 exhibited an increase in inpatient services and a decrease in outpatient services. There was a 16.17% increase in inpatient cost, 8.55% increase in inpatient admission, 10.67% increase in inpatient length of hospitalization, -9.14% decline in outpatient cost, and -6.79% decline in outpatient visits. Regarding children in the age groups of 6-10 and 11-15, the effect of the policy was inconclusive. CONCLUSION: The reduction in coinsurance rate policy in hospitalization among children has increased inpatient services and reduced outpatient services for 1-5-year-olds-a substitute effect was observed in this group. There is need for further research to examine the long-term effects of the coinsurance reduction policy.

Effect of regional medical disparities on complications in patients with hypertension: Cox's proportional hazard models.

Objective: Complications associated with hypertension can be alleviated by providing necessary medical services. However, there may be disparities in their provision depending on regional differences. Thus, this study aimed to examine the effects of regional healthcare disparities on complications in patients with hypertension in South Korea. Methods: Data from the National Health Insurance Service National Sample Cohort (2004-2019) were analyzed. The position value for the relative composite index was used to identify medically vulnerable regions. The diagnosis of hypertension within the region was also considered. The risk of complications associated with hypertension included cardiovascular, cerebrovascular, and kidney diseases. Cox proportional hazards models were used for statistical analysis. Results: A total of 246,490 patients were included in this study. Patients who lived in medically vulnerable regions and were diagnosed outside their residential area had a higher risk of complications than those living in non-vulnerable regions and were diagnosed outside the residential area (hazard ratio: 1.156, 95% confidence interval: 1.119-1.195). Conclusion: Patients living in medically vulnerable regions who were diagnosed outside their residential areas were more likely to have hypertension complications regardless of the type of complication. Necessary policies should be implemented to reduce regional healthcare disparities.

Use of Bluetooth contact tracing technology to model COVID-19 quarantine policies in high-risk closed populations.

Containment measures in high-risk closed settings, like migrant worker (MW) dormitories, are critical for mitigating emerging infectious disease outbreaks and protecting potentially vulnerable populations in outbreaks such as coronavirus disease 2019 (COVID-19). The direct impact of social distancing measures can be assessed through wearable contact tracing devices. Here, we developed an individual-based model using data collected through a Bluetooth wearable device that collected 33.6M and 52.8M contact events in two dormitories in Singapore, one apartment style and the other a barrack style, to assess the impact of measures to reduce the social contact of cases and their contacts. The simulation of highly detailed contact networks accounts for different infrastructural levels, including room, floor, block, and dormitory, and intensity in terms of being regular or transient. Via a branching process model, we then simulated outbreaks that matched the prevalence during the COVID-19 outbreak in the two dormitories and explored alternative scenarios for control. We found that strict isolation of all cases and quarantine of all contacts would lead to very low prevalence but that quarantining only regular contacts would lead to only marginally higher prevalence but substantially fewer total man-hours lost in quarantine. Reducing the density of contacts by 30% through the construction of additional dormitories was modelled to reduce the prevalence by 14 and 9% under smaller and larger outbreaks, respectively. Wearable contact tracing devices may be used not just for contact tracing efforts but also to inform alternative containment measures in high-risk closed settings.

Effectiveness of chatbots on COVID vaccine confidence and acceptance in Thailand, Hong Kong, and Singapore.

Chatbots have become an increasingly popular tool in the field of health services and communications. Despite chatbots' significance amid the COVID-19 pandemic, few studies have performed a rigorous evaluation of the effectiveness of chatbots in improving vaccine confidence and acceptance. In Thailand, Hong Kong, and Singapore, from February 11th to June 30th, 2022, we conducted multisite randomised controlled trials (RCT) on 2,045 adult guardians of children and seniors who were unvaccinated or had delayed vaccinations. After a week of using COVID-19 vaccine chatbots, the differences in vaccine confidence and acceptance were compared between the intervention and control groups. Compared to non-users, fewer chatbot users reported decreased confidence in vaccine effectiveness in the Thailand child group [Intervention: 4.3 % vs. Control: 17%, P = 0.023]. However, more chatbot users reported decreased vaccine acceptance [26% vs. 12%, P = 0.028] in Hong Kong child group and decreased vaccine confidence in safety [29% vs. 10%, P = 0.041] in Singapore child group. There was no statistically significant change in vaccine confidence or acceptance in the Hong Kong senior group. Employing the RE-AIM framework, process evaluation indicated strong acceptance and implementation support for vaccine chatbots from stakeholders, with high levels of sustainability and scalability. This multisite, parallel RCT study on vaccine chatbots found mixed success in improving vaccine confidence and acceptance among unvaccinated Asian subpopulations. Further studies that link chatbot usage and real-world vaccine uptake are needed to augment evidence for employing vaccine chatbots to advance vaccine confidence and acceptance.

Regional Differences in Medical Costs of Chronic Kidney Disease in the South Korean Population: Marginalized Two-Part Model.

BACKGROUND: There are regional gaps in the access to medical services for patients with chronic kidney disease (CKD), and it is necessary to reduce those gaps, including the gaps involving medical costs. OBJECTIVE: This study aimed to analyze regional differences in the medical costs associated with CKD in the South Korean population. METHODS: This longitudinal cohort study included participants randomly sampled from the National Health Insurance Service-National Sample Cohort of South Korea. To select those who were newly diagnosed with CKD, we excluded those who were diagnosed in 2002-2003 and 2018-2019. A total of 5903 patients with CKD were finally included. We used a marginalized two-part longitudinal model to assess total medical costs. RESULTS: Our cohort included 4775 (59.9%) men and 3191 (40.1%) women. Of these, 971 (12.2%) and 6995 (87.8%) lived in medically vulnerable and nonvulnerable regions, respectively. The postdiagnosis costs showed a significant difference between the regions (estimate: -0.0152, 95% confidence limit: -0.0171 to -0.0133). The difference in medical expenses between the vulnerable and nonvulnerable regions showed an increase each year after the diagnosis. CONCLUSIONS: Patients with CKD living in medically vulnerable regions are likely to have higher postdiagnostic medical expenses compared to those living in regions that are not medically vulnerable. Efforts to improve early diagnosis of CKD are needed. Relevant policies should be drafted to decrease the medical costs of patients with CKD disease living in medically deprived areas.

Economic Analysis of Border Control Policies during COVID-19 Pandemic: A Modelling Study to Inform Cross-Border Travel Policy between Singapore and Thailand.

With countries progressing towards high COVID-19 vaccination rates, strategies for border reopening are required. This study focuses on Thailand and Singapore, two countries that share significant tourism visitation, to illustrate a framework for optimizing COVID-19 testing and quarantine policies for bilateral travel with a focus on economic recovery. The timeframe is the month of October 2021, when Thailand and Singapore were preparing to reopen borders for bilateral travel. This study was conducted to provide evidence for the border reopening policy decisions. Incremental net benefit (INB) compared to the pre-opening period was quantified through a willingness-to-travel model, a micro-simulation COVID-19 transmission model and an economic model accounting for medical and non-medical costs/benefits. Multiple testing and quarantine policies were examined, and Pareto optimal (PO) policies and the most influential components were identified. The highest possible INB for Thailand is US $125.94 million, under a PO policy with no quarantine but with antigen rapid tests (ARTs) pre-departure and upon arrival to enter both countries. The highest possible INB for Singapore is US $29.78 million, under another PO policy with no quarantine on both sides, no testing to enter Thailand, and ARTs pre-departure and upon arrival to enter Singapore. Tourism receipts and costs/profits of testing and quarantine have greater economic impacts than that from COVID-19 transmission. Provided healthcare systems have sufficient capacity, great economic benefits can be gained for both countries by relaxing border control measures.

Association between smoking status and subjective quality of sleep in the South Korean population: a cross-sectional study.

PURPOSE: This study aimed to investigate the relationship between smoking and subjective sleep quality in the Korean adult population. METHODS: We designed a cross-sectional survey using data from the 2018 Korean Community Health Service Conditions Survey and selected smoking status as our variable of interest. We divided the participants into people who currently, never, and formerly smoked, those who smoked < 20 cigarettes/day, and those who smoked > 20 cigarettes/day. Subjective sleep quality was analyzed using the Pittsburgh Sleep Quality Index. Multiple logistic regression analysis was performed for statistical analysis. RESULTS: A total of 174,665 participants were enrolled. People who formerly and currently smoked were found to have poorer subjective sleep quality than those who never smoked. The odds of poor subjective sleep quality in people who smoked > 20 cigarettes/day were 1.15 times (95% confidence interval: 1.09-1.21) for men and 1.51 times (95% confidence interval: 1.22-1.86) for women, compared with men and women who never smoked. CONCLUSIONS: Smoking was negatively associated with subjective sleep quality. Smoking cessation programs and lifestyle improvement education may be justifiable to improve the quality of sleep in Korean adults.

Association between serum lipid levels over time and risk of Parkinson's disease.

The role of serum lipids in Parkinson's disease (PD) remains controversial. We aimed to evaluate the association between time-varying serum lipid levels and the risk of PD. This study included an assessment of the complete lipid profiles of 200,454 individuals from the 2002-2019 Korean National Health Insurance Health Screening Cohort. Time-dependent Cox proportional hazard regression models were used to evaluate the association between serum lipid levels over time and the risk of PD. Individuals in the lowest tertile of total cholesterol and low-density lipoprotein cholesterol had a 1.17 times [hazard ratio (HR) 1.17; 95% confidence interval (CI) 1.04-1.31] and 1.19 times (HR 1.19; 95% CI 1.06-1.34) higher risk of PD than those in middle tertile, respectively. Individuals in the highest high-density lipoprotein cholesterol tertile had a 0.89 times (HR 0.89; 95% CI 0.79-1.00) lower risk of PD than those in middle tertile, but the association was less robust in sensitivity analyses. Serum triglyceride levels were not related to the risk of PD. Our results suggest that the serum total and low-density lipoprotein cholesterol levels over time are inversely associated with the risk of PD. Further research is warranted to confirm these findings and reveal the underlying mechanisms.

High prevalence of hypertension among smokers of conventional and e-cigarette: Using the nationally representative community dwelling survey.

This study aimed to clarify the association between hypertension and conventional cigarette and electronic cigarette (e-cigarette) use, together or individually. A total of 275,762 participants were included, of which 120,766 were men and 154,996 were women. The data were drawn from the Korea Community Health Survey conducted in 2019. A multiple logistic regression model was used to examine the association between hypertension and types of smoking. Hypertension was defined as systolic blood pressure higher than 140 mmHg or diastolic blood pressure higher than 90 mmHg. Based on the types of smoking, participants were grouped as dual smokers of conventional and e-cigarettes, e-cigarette only smokers, conventional cigarette only smokers, past-smokers, and non-smokers. Compared to non-smokers, dual smokers presented the highest odds ratio for hypertension in the male [odds ratio (OR): 1.24, confidence interval (CI): 1.10 to 1.39] and female groups (OR: 1.44 CI: 0.96 to 2.15). According to the Cochran-Mantel-Haenszel test, the two-sided p-value of < 0.001 indicated an overall statistically significant association between types of smoking and hypertension. Use of both cigarette types was statistically significant in the male group, but only the use of conventional cigarettes and past smoking were statistically significant in the female group. Among smokers of the two cigarette types, those who were dual smokers of e-cigarettes and conventional cigarettes were the most likely to have the highest prevalence of hypertension.

Structural analysis of the pseudaminic acid synthase PseI from Campylobacter jejuni.

Campylobacter jejuni PseI is a pseudaminic acid synthase that condenses the 2,4-diacetamido-2,4,6-trideoxy-l-altrose sugar (6-deoxy AltdiNAc) and phosphoenolpyruvate to generate pseudaminic acid, a sialic acid-like 9-carbon backbone α-keto sugar. Pseudaminic acid is conjugated to cell surface proteins and lipids and plays a key role in the mobility and virulence of C. jejuni and other pathogenic bacteria. To provide insights into the catalytic mechanism of PseI, we performed a structural study on PseI. PseI forms a two-domain structure and assembles into a domain-swapped homodimer. The PseI dimer has two cavities, each of which accommodates a metal ion using conserved histidine residues. A comparative analysis of structures and sequences suggests that the cavity of PseI functions as an active site that binds the 6-deoxy AltdiNAc and phosphoenolpyruvate substrates and mediates their condensation. Furthermore, we propose the substrate binding-induced structural rearrangement of PseI and predict 6-deoxy AltdiNAc recognition residues that are specific to PseI.

Association between parents' country of birth and smoking risks in South Korean adolescents.

This study aimed to determine whether significant associations exist between multicultural families and adolescent smoking risks in South Korea. Data from the Korea Youth Risk Behavior Web-based survey from 2016 to 2020 were analyzed. Participants were classified into four family types (South Korean mother-foreign father, South Korean father-foreign mother, both foreign parents, and both South Korean parents) according to their parents' country of birth and smoking was assessed using a self-reported questionnaire. A logistic regression analysis was used to examine the significance of the associations. Overall, 194,259 participants (boys: 94,793, girls: 99,466) enrolled in this study. Adolescents whose parents were born overseas were more likely to smoke than native South Korean adolescents (boys: odds ratio [OR] = 2.61, confidence interval [CI] = 1.79-3.81, girls: OR 3.94, CI 2.42-6.43). When the mother's country of birth was a developing country, there was an increased likelihood of girls smoking, and there was an increased likelihood of smoking among boys when the mother's country of birth was North Korea. When both parents were born abroad, and the mother's country of birth was a developing country, the likelihood of smoking risks among their multicultural teenage children increased. Policies and interventions need to be established and implemented to lower the smoking rate among multicultural teenagers.

Difference in medical service use among Korean gastric cancer survivors according to regional healthcare vulnerabilities: a cohort study.

PURPOSE: This study investigated the relationship between medical service use and healthcare vulnerability, pre- and post-gastric cancer diagnosis. Differences between healthcare-vulnerable and healthcare-nonvulnerable regions identified inequities that require intervention. METHODS: This cohort study was done using the National Health Insurance claims data of patients diagnosed with gastric cancer between 2004 and 2013. The Position Value for Relative Comparison Index was used to determine whether the patients lived in a healthcare-vulnerable region. Medical service use was classified into annual outpatient treatment, hospitalization days, and emergency treatment. We used a generalized linear model to which the Poisson distribution was applied and compared regional differences in medical service use. RESULTS: A total of 1797 gastric cancer patients who had survived 5 years post-diagnosis were included in the study, of which 14.2% lived in healthcare-vulnerable regions. The patients in vulnerable regions surviving 5-7 years post-diagnosis had a higher number of outpatient visits than those in nonvulnerable regions. Furthermore, hospitalization days were lesser for patients in vulnerable regions who survived 6 years post-diagnosis than those in nonvulnerable regions; however, this number increased in the seventh year. CONCLUSIONS: Our results suggest that gastric cancer survivors living in healthcare-vulnerable regions have a higher probability of increased medical service use 5 years post-diagnosis compared with patients in nonvulnerable regions, which may significantly increase healthcare disparities over time. Therefore, in the future, additional research is needed to elucidate the causes of the disparities in healthcare use and the results of the differences in health outcomes.

Association between family financial decline due to COVID-19 and generalized anxiety disorder among Korean adolescents.

BACKGROUND: COVID-19 has had a worldwide economic impact. A decline in family financial level can adversely affect adolescents' mental health. This study examined the association between perceived family financial decline due to COVID-19 and generalized anxiety disorder (GAD) among South Korean adolescents. METHODS: Data from 54,948 middle and high school students from the 2020 Korea Youth Risk Behavior Survey were collected in this cross-sectional study. The effect of the perceived family financial decline due to COVID-19 related to GAD was analyzed using binary and multinomial logistic regression. RESULTS: The relationship between perceived family financial decline due to COVID-19 and GAD was linear with increasing odds ratios and confidence intervals (the possibility of GAD, no financial decline: OR 1.00, mild: OR 1.11, CI 1.05-1.17, moderate: OR 1.30, CI 1.22-1.39, severe: OR 1.48, CI 1.34-1.63). Girls, low-income class, and living with family were vulnerable to GAD. GAD levels of mild, moderate, and severe were most likely to occur in each case of mild, moderate, and severe financial decline, respectively. LIMITATIONS: As this is a cross-sectional study, causality is unknown. Because this study data was self-reported by adolescents, they may have been overestimated or underestimated. CONCLUSION: GAD in adolescents is closely related to perceived decreased family finances due to COVID-19. The dose-response of GAD according to financial decline became gradually severe. Anxious adolescents were afraid of uncertain and adverse outcomes affecting them or their families. Therefore, there is a vital need to care for financially affected adolescents.