Incidence and risk factors of COVID-19 in a tertiary hospital and the effectiveness of booster vaccination among health care workers: A retrospective cohort study, January 2020 to June 2022.

BACKGROUND: Health care workers (HCWs) face a higher risk of infection and may transmit pathogens to patients during a pandemic. This study aims to evaluate infection-control measures by analyzing the incidence and risk factors of COVID-19 and estimating vaccine effectiveness (VE) at a tertiary hospital in Seoul, Republic of Korea. METHODS: This study included 2,516 HCWs from January 1, 2020, to June 30, 2022. Data were analyzed to determine the incidence density and cumulative incidence; the results were compared by the age- and gender-specific standardized incidence ratios (SIR). VE was estimated with multivariate Cox proportional-hazard models as 1-adjusted hazard ratio × 100%. RESULTS: SIR indicated a lower COVID-19 risk in the hospital population than in the general Korean population (SIR, 0.81; 95% confidence interval [CI]: 0.76-0.87). Multivariate Cox analysis indicated that, compared to doctors, nonmedical service supporters and other HCWs (excluding doctors and nurses) were high-risk groups (adjusted hazard ratio [95% CI], 1.72 [1.04-2.83] and 1.76 [1.20-2.58], respectively). Compared to the outpatient unit, the emergency department was a high-risk department (1.70 [1.16-2.50]). The VE of the booster dose was 55.47%, compared to no or incomplete vaccination (95% CI: 22.63-74.37). CONCLUSIONS: Besides encouraging HCWs vaccination, effective infection-control measures should target high-risk groups and departments.

Healthy immigrants, unhealthy ageing? Analysis of health decline among older migrants and natives across European countries.

The probability of having multiple chronic conditions simultaneously, or multimorbidity, tends to increase with age. Immigrants face a particularly high risk of unhealthy ageing. This study investigates the immigrant-native disparities in the speed of age-related chronic disease accumulation, focusing on the number of chronic health conditions; and considers the heterogeneity of this trajectory within immigrant populations by origin and receiving country. We use data from the Survey of Health, Ageing and Retirement in Europe from 2004 to 2020 on adults aged 50 to 79 from 28 European countries and employ both cross-sectional and longitudinal analyses. For longitudinal panel analyses, we use fixed-effects regression models to account for the unobserved heterogeneity related to individual characteristics including migration background. Our results indicate that immigrants report a higher number of chronic conditions at all ages relative to their native-born peers, but also that the immigrant-native differential in the number of chronic conditions decreases from age 65 onwards. When considering differences by origin country, we find that the speed of chronic disease accumulation is slower among immigrants from the Americas and the Asia and Oceania country groups than it is among natives. When looking at differences by receiving country group, we observe that the speed of accumulating chronic diseases is slower among immigrants in Eastern Europe than among natives, particularly at older ages. Our findings suggest that age-related trajectories of health vary substantially among immigrant populations by origin and destination country, which underscore that individual migration histories play a persistent role in shaping the health of ageing immigrant populations throughout the life course.

Healthcare Utilization and Costs According to Frailty Transitions After Two Years: A Korean Frailty and Aging Cohort Study.

BACKGROUND: Korea's aging population has raised several challenges, especially concerning healthcare costs. Consequently, this study evaluated the association of frailty transitions with healthcare utilization and costs for older adults aged 70 to 84. METHODS: This study linked the frailty status data of the Korean Frailty and Aging Cohort Study to the National Health Insurance Database. We included 2,291 participants who had frailty measured by Fried Frailty phenotype at baseline in 2016-2017 and follow-up in 2018-2019. We conducted a multivariate regression analysis to determine the association between their healthcare utilization and costs by frailty transition groups. RESULTS: After 2 years, changes from "pre-frail" to "frail" (Group 6) and "frail" to "pre-frail" (Group 8) were significantly associated with increased inpatient days (P < 0.001), inpatient frequency (P < 0.001), inpatient cost (P < 0.001 and P < 0.01, respectively), and total healthcare cost (P < 0.001) than "robust" to "robust" (Group 1) older adults. A transition to frailty from "pre-frail" to "frail" (Group 6) resulted in a $2,339 total healthcare cost increase, and from "frail" to "pre-frail" (Group 8), a $1,605, compared to "robust" to "robust" older adults. CONCLUSION: Frailty among community-dwelling older adults is economically relevant. Therefore, it is crucial to study the burden of medical expenses and countermeasures for older adults to not only provide appropriate medical services but also to prevent the decline in their living standards due to medical expenses.

Relative Effectiveness of COVID-19 Vaccination in Healthcare Workers: 3-Dose Versus 2-Dose Vaccination.

The omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to have high infectivity and is more likely to evade vaccine immunity. However, booster vaccination is expected to strengthen cross-reactive immunity, thereby increasing the vaccine effectiveness (VE). This study aimed to evaluate the relative VE of the 3-dose (booster) vaccination compared with the 2-dose primary series vaccination in healthcare workers during omicron variant-dominant periods. During the omicron-dominant period from February 1, 2022 to February 28, 2022, a 1:1 matched case-control study was conducted. Healthcare workers with positive SARS-CoV-2 test results were classified as positive cases, whereas those with negative results served as controls. Compared with the 2-dose primary series vaccination, booster vaccination with mRNA vaccine showed moderate VE (53.1%). However, in multivariate analysis including the time elapsed after vaccination, the significant VE disappeared, reflecting the impact of recent vaccination rather than the third dose itself.

Factors shaping the COVID-19 epidemic curve: a multi-country analysis.

BACKGROUND: Lockdown measures are the backbone of containment measures for the COVID-19 pandemic both in high-income countries (HICs) and low- and middle-income countries (LMICs). However, in view of the inevitably-occurring second and third global covid-19 wave, assessing the success and impact of containment measures on the epidemic curve of COVID-19 and people's compliance with such measures is crucial for more effective policies. To determine the containment measures influencing the COVID-19 epidemic curve in nine targeted countries across high-, middle-, and low-income nations. METHODS: Four HICs (Germany, Sweden, Italy, and South Korea) and five LMICs (Mexico, Colombia, India, Nigeria, and Nepal) were selected to assess the association using interrupted time series analysis of daily case numbers and deaths of COVID-19 considering the following factors: The "stringency index (SI)" indicating how tight the containment measures were implemented in each country; and the level of compliance with the prescribed measures using human mobility data. Additionally, a scoping review was conducted to contextualize the findings. RESULTS: Most countries implemented quite rigorous lockdown measures, particularly the LMICs (India, Nepal, and Colombia) following the model of HICs (Germany and Italy). Exceptions were Sweden and South Korea, which opted for different strategies. The compliance with the restrictions-measured as mobility related to home office, restraining from leisure activities, non-use of local transport and others-was generally good, except in Sweden and South Korea where the restrictions were limited. The endemic curves and time-series analysis showed that the containment measures were successful in HICs but not in LMICs. CONCLUSION: The imposed lockdown measures are alarming, particularly in resource-constrained settings where such measures are independent of the population segment, which drives the virus transmission. Methods for examining people's movements or hardships that are caused by covid- no work, no food situation are inequitable. Novel and context-adapted approach of dealing with the COVID-19 crisis are therefore crucial.

Comorbidities and Factors Determining Medical Expenses and Length of Stay for Admitted COVID-19 Patients in Korea.

PURPOSE: No previous investigations of coronavirus disease 2019 (COVID-19) have estimated medical expenses, length of stay, or factors influencing them using administrative datasets. This study aims to fill this research gap for the Republic of Korea, which has over 10,000 confirmed COVID-19 cases. PATIENTS AND METHODS: Using the nationwide health insurance claims data of 7590 confirmed COVID-19 patients, we estimated average medical expenses and inpatient days per patient, and performed multivariate negative binomial, and gamma regressions to determine influencing factors for higher outcomes. RESULTS: According to the results, COVID-19 patients with history of ICU admission, chest CT imaging, lopinavir/ritonavir and hydroxychloroquine use stayed longer in the hospital and spent more on medical expenses, and anti-hypertensive drugs were insignificantly associated with the outcomes. Female patients stayed longer in the hospital in the over 65 age group but spent less in medical expenses that the 20-39 group. In the 40-69 age group, patients with health insurance stayed longer in the hospital and spent more on medical expenses than those aged over 65 years. Comorbidities did not affect outcomes in most age groups. CONCLUSION: In summary, contrary to popular beliefs, medical expenses and length of hospitalization were mostly influenced by age, and not by comorbidities, anti-viral, or anti-hypertensive drugs. Thus, responses should focus on infection prevention and control rather than clinical countermeasures.

Risk Factors of Outcomes of COVID-19 Patients in Korea: Focus on Early Symptoms.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has spread around the globe, and it is important to determine the risk factors of death in the general population. Our study aimed to determine the risk factors of death and severe illness requiring supplemental oxygen therapy based on the demographic and clinical characteristics of COVID-19 patients in Korea. METHODS: In this study, we used data provided by the Korea Disease Control and Prevention Agency (KDCA) and analyzed a total of 5,068 patients with COVID-19, excluding 19 pregnant women and 544 individuals with missing data. We performed logistic regression analysis to determine the impact of early symptoms on survival and severe disease. Logistic regression models included sex, age, number of comorbidities, symptoms on admission, blood pressure, heart rate, and body temperature as explanatory variables, and death and oxygen therapy as outcome variables. RESULTS: Logistic regression analyses revealed that the male sex, older age (≥ 60 years), higher number of comorbidities, presence of symptoms on admission, heart rate ≥ 120 bpm, and body temperature ≥ 37.5°C presented with higher risk of in-hospital death and oxygen therapy requirement. Conversely, rhinorrhea and headache were associated with a low risk of death and oxygen therapy requirement. The findings showed that cough, sputum, and fever were the most common symptoms on admission, while 25.3% of patients with COVID-19 were asymptomatic. CONCLUSION: COVID-19 patients with high-risk early symptoms on admission, such as dyspnea and altered mental status, and those without low-risk symptoms of rhinorrhea and headache should be included in priority treatment groups.

The Covid-19 pandemic in low- and middle-income countries, who carries the burden? Review of mass media and publications from six countries.

During the Covid-19 pandemic, rich countries employed lockdown and physical distancing policies for transmission control. However, the question still remains whether these measures are also suitable in countries with a fragile economy, which rests mainly on the informal sector. The impacts of lockdown measures in disadvantaged population strata in six low- and middle-income countries (LMICs) were reviewed using i) 93 media reports and ii) 17 published scientific papers. This review showed that those who suffered the most from the lockdown were migrants, workers in the large informal sector, small businesses, slum dwellers, women and elderly, revealing the social, cultural and economic inequalities of societies. Financial and food support for the poor was inadequate and sometimes mismanaged. In the better organized societies, the resilience was stronger (South Korea, Kerala/India) but here also the poor had to suffer the most. It is strongly recommended that outbreak response strategies should particularly focus on the poor and vulnerable population.

Influencing Factors of Transportation Costs Regarding Healthcare Service Utilization in Korea.

BACKGROUND: Transportation costs can be a barrier to healthcare services, especially for low-income, disabled, elderly, and geographically isolated populations. This study aimed to estimate the transportation costs of healthcare service utilization and related influencing factors in Korea in 2016. METHODS: Transportation costs were calculated using data from the 2016 Korea Health Panel Study. A total of 14,845 participants were included (males, 45.07%; females, 54.93%), among which 2,148 participants used inpatient and 14,787 used outpatient care services. Transportation costs were estimated by healthcare types, transportation modes, and all disease and injury groups that caused healthcare service utilization. The influencing factors of higher transportation costs were analyzed using multivariable regression analysis. RESULTS: In 2016, the average transportation costs were United States dollars (USD) 43.70 (purchasing power parity [PPP], USD 32.35) per year and USD 27.67 (PPP, USD 20.48) per visit for inpatient care; for outpatient case, costs were USD 41.43 (PPP, USD 30.67) per year and USD 2.09 (PPP, USD 1.55) per visit. Among disease and injury groups, those with neoplasms incurred the highest transportation costs of USD 9.73 (PPP, USD 7.20). Both inpatient and outpatient annual transportation costs were higher among severely disabled individuals (inpatient, +USD 44.71; outpatient, +USD 23.73) and rural residents (inpatient, +USD 20.40; outpatient, +USD 28.66). Transportation costs per healthcare visit were influenced by healthcare coverage and residential area. Sex, age, and income were influencing factors of higher transportation costs for outpatient care. CONCLUSION: Transportation cost burden was especially high among those with major non-communicable diseases (e.g., cancer) or living in rural areas, as well as elderly, severely disabled, and low-income populations. Thus, there is a need to address the socioeconomic disparities related to healthcare transportation costs in Korea by implementing targeted interventions in populations with restricted access to healthcare.

Years of Life Lost Attributable to COVID-19 in High-incidence Countries.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is a major public health problem of international concern. It is important to estimate its impact of COVID-19 for health policy decision-making. We estimated the years of life lost (YLLs) due to COVID-19 in high-incidence countries. METHODS: We collected the YLLs due to COVID-19 in 30 high-incidence countries as of April 13, 2020 and followed up as of July 14, 2020. Incidence and mortality were collected using each country's formal reports, articles, and other electronic sources. The life expectancy of Japanese females by age and the UN population data were used to calculate YLLs in total and per 100,000. RESULTS: As of April 22, 2020, there were 1,699,574 YLLs due to COVID-19 in 30 high-incidence countries. On July 14, 2020, this increased to 4,072,325. Both on April 22 and July 14, the total YLLs due to COVID-19 was highest in the USA (April 22, 534,481 YLLs; July 14, 1,199,510 YLLs), and the YLLs per 100,000 population was highest in Belgium (April 22, 868.12 YLLs/100,000; July 14, 1,593.72 YLLs/100,000). YLLs due to COVID-19 were higher among males than among females and higher in those aged ≥ 60 years than in younger individuals. Belgium had the highest proportion of YLLs attributable to COVID-19 as a proportion of the total YLLs and the highest disability-adjusted life years per 100,000 population. CONCLUSION: This study estimated YLLs due to COVID-19 in 30 countries. COVID-19 is a high burden in the USA and Belgium, among males and the elderly. The YLLs are very closely related with the incidence as well as the mortality. This highlights the importance of the early detection of incident case that minimizes severe acute respiratory syndrome coronavirus-2 fatality.

Estimating Disability-Adjusted Life Years due to Tuberculosis in Korea through to the Year 2040.

Despite efforts to reduce its incidence, tuberculosis continues to burden the rapidly aging Korean society. This study aimed to investigate the current trend of tuberculosis burden in Korea and its projections to 2040. We used National Health Insurance claims data to calculate the disability-adjusted life years due to tuberculosis in Korea. Disability-adjusted life years were measured by summing the years of life lost and the years lived with disability using an incidence-based approach. We modeled the incidence rates using a time-series model for the projection of disability-adjusted life years accrued from 2020 to 2040. The total disability-adjusted life years due to tuberculosis were 69, 64, 59, and 49 disability-adjusted life years/100,000 population in 2014, 2015, 2016, and 2017, respectively. In both sexes, disability-adjusted life years were the highest in those aged ≥80 years. Projected disability-adjusted life years showed a descending trend from 38 disability-adjusted life years/100,000 in 2020, to 14 disability-adjusted life years/100,000 in 2040. Conversely, the projected disability-adjusted life years increased among females aged ≥80 years. Although the tuberculosis burden in Korea is decreasing, a high burden remains among the elderly. Therefore, interventions targeting those vulnerable are required.

The Neglected Role of Physical Education Participation on Suicidal Ideation and Stress in High School Adolescents from South Korea.

Adolescents are at high risk of suicidal ideation and stress. This study aimed to investigate how physical education participation predicts suicidal ideation and stress in South Korean high school students. Data from the Twelfth Korea Youth Risk Behaviour Web-Based Survey 2016 (KYRBS) were used for analyses. Two multiple logistic regressions were performed to determine the influence of selected factors on suicidal ideation and stress (model 1: subjective health, social support, body mass index, academic achievement, perceived economic status of family, and physical education participation; model 2: adjusting for school type and year). Model 2 revealed negative associations between subjective health, academic achievement, perceived economic status of family, social support, physical education participation (≥2 times/weekly), and suicidal ideation for male students. Female students exhibited negative associations between subjective health, social support, and academic achievement, along with a positive association between body mass index and suicidal ideation. For both genders, stress was negatively associated with subjective health, social support, academic achievement, perceived economic status of family, and physical education participation (≥2 times/weekly). These findings suggest that participating in physical education can mitigate the risk of suicidal ideation and stress among high school students.