Comparative analysis between STANDARD-E Covi-FERON ELISA with pre-existing IFN-γ release assays and determination of the optimum cutoff value for assessment of T-Cell response to SARS-CoV-2.

BACKGROUND: Interferon-gamma (IFN-γ) release assays (IGRAs) are useful for the assessment of the T-cell response to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). We aimed to assess the performance of the newly developed IGRA ELISA test compared to the pre-existing assays and to validate the cutoff value in real-world conditions. METHODS: We enrolled 219 participants and assessed agreement between STANDARD-E Covi-FERON ELISA with Quanti-FERON SARS-CoV-2 (QFN SARS-CoV-2), as well as with T SPOT Discovery SARS-CoV-2 based on Cohen's kappa-index. We further determined the optimal cutoff value for the Covi-FERON ELISA according to the immune response to vaccinations or infections. RESULTS: We found a moderate agreement between Covi-FERON ELISA and QFN SARS-CoV-2 before vaccination (kappa-index = 0.71), whereas a weak agreement after the first (kappa-index = 0.40) and second vaccinations (kappa-index = 0.46). However, the analysis between Covi-FERON ELISA and T SPOT assay demonstrated a strong agreement (kappa-index >0.7). The cut-off value of the OS (original spike) marker was 0.759 IU/mL with a sensitivity of 96.3% and specificity of 78.7%, and that of the variant spike (VS) marker was 0.663 IU/mL with a sensitivity and specificity of 77.8% and 80.6%, respectively. CONCLUSION: The newly determined cut-off value may provide an optimum value to minimize and prevent the occurrence of false-negative or false-positive during the assessment of T-cell immune response using Covi-FERON ELISA under real-world conditions.

Assessment of Frailty Index at 66 Years of Age and Association With Age-Related Diseases, Disability, and Death Over 10 Years in Korea.

Importance: A frailty index has been proposed as a measure of aging among older individuals. However, few studies have examined whether a frailty index measured at the same chronologic age at younger ages could forecast the development of new age-related conditions. Objective: To examine the association of the frailty index at 66 years of age with incident age-related diseases, disability, and death over 10 years. Design, Setting, and Participants: This retrospective nationwide cohort study used the Korean National Health Insurance database to identify 968 885 Korean individuals who attended the National Screening Program for Transitional Ages at 66 years of age between January 1, 2007, and December 31, 2017. Data were analyzed from October 1, 2020, to January 2022. Exposures: Frailty was defined using a 39-item frailty index ranging from 0 to 1.00 as robust (<0.15), prefrail (0.15-0.24), mildly frail (0.25-0.34), and moderately to severely frail (≥0.35). Main Outcomes and Measures: The primary outcome was all-cause death. Secondary outcomes were 8 age-related chronic diseases (congestive heart failure, coronary artery disease, stroke, type 2 diabetes, cancer, dementia, fall, and fracture) and disability qualifying for long-term care services. Cox proportional hazards regression and cause-specific and subdistribution hazards regression were used to examine hazard ratios (HRs) and 95% CIs for the outcomes until the earliest of date of death, the occurrence of relevant age-related conditions, 10 years from the screening examination, or December 31, 2019. Results: Among the 968 885 participants included in the analysis (517 052 women [53.4%]), the majority were classified as robust (65.2%) or prefrail (28.2%); only a small fraction were classified as mildly frail (5.7%) or moderately to severely frail (1.0%). The mean frailty index was 0.13 (SD, 0.07), and 64 415 (6.6%) were frail. Compared with the robust group, those in the moderately to severely frail group were more likely to be women (47.8% vs 61.7%), receiving medical aid insurance for low income (2.1% vs 18.9%), and less active (median, 657 [IQR, 219-1133] vs 319 [IQR, 0-693] metabolic equivalent task [min/wk]). After adjusting for sociodemographic and lifestyle characteristics, moderate to severe frailty was associated with increased rates of death (HR, 4.43 [95% CI, 4.24-4.64]) and new diagnosis of all chronic diseases, including congestive heart failure (adjusted cause-specific HR, 2.90 [95% CI, 2.67-3.15]), coronary artery disease (adjusted cause-specific HR, 1.98 [95% CI, 1.85-2.12]), stroke (adjusted cause-specific HR, 2.22 [95% CI, 2.10-2.34]), diabetes (adjusted cause-specific HR, 2.34 [95% CI, 2.21-2.47]), cancer (adjusted cause-specific HR, 1.10 [95% CI, 1.03-1.18]), dementia (adjusted cause-specific HR, 3.59 [95% CI, 3.42-3.77]), fall (adjusted cause-specific HR, 2.76 [95% CI, 2.29-3.32]), fracture (adjusted cause-specific HR, 1.54 [95% CI, 1.48-1.62]), and disability (adjusted cause-specific HR, 10.85 [95% CI, 10.00-11.70]). Frailty was associated with increased 10-year incidence of all the outcomes, except for cancer (moderate to severe frailty adjusted subdistribution HR, 0.99 [95% CI, 0.92-1.06]). Frailty at 66 years of age was associated with greater acquisition of age-related conditions (mean [SD] conditions per year for the robust group, 0.14 [0.32]; for the moderately to severely frail group, 0.45 [0.87]) in the next 10 years. Conclusions and Relevance: The findings of this cohort study suggest that a frailty index measured at 66 years of age was associated with accelerated acquisition of age-related conditions, disability, and death over the next 10 years. Measuring frailty at this age may offer opportunities to prevent age-related health decline.

Biological Assessment of Potential Exposure to Occupational Substances in Current Semiconductor Workers with at Least 5 Years of Employment.

BACKGROUND: this study aimed to conduct a biological assessment of the potential exposure to carcinogenic substances in current semiconductor workers. METHODS: A cross-sectional study was conducted on 306 semiconductor workers. The assessed biomarkers were as follows: (benzene) urine S-phenylmercapturic, trans,trans-muconic acid, blood benzene; (trichloroethylene) urine trichloroacetic acid; (2-ethoxyethanol) 2-ethoxyacetic acid; (arsine) urine arsenic3+, arsenic5+, monomethylarsonic, dimethylarsinic acid, arsenobetaine; (shift work) 6-hydroxymelatonin; (smoking) cotinine, and (radiation). The detection rate of these materials is defined as more than the biological exposure index (BEI) or the previous reference value. RESULTS: Some workers exposed to trans,trans-muconic acid, trichloroacetic acid, and arsenic5+ showed high BEI levels. Generally, there was no difference according to job categories, and workers were suspected to be exposed to other sources. The melatonin concentration tended to decrease when working at night, and cotinine was identified as an excellent surrogate marker for smoking. In the case of radiation exposure, there was no significant difference in the number of stable chromosome translocation in 19 semiconductor workers. Their estimated radiation exposure level was below the limit of detection (LOD) or near the LOD level. CONCLUSION: In this study, most carcinogens were below the BEI level, but verification through re-measurement was needed for workers who were identified to have a high BEI level. For continuous monitoring, a prospective cohort is necessary to deal with the healthy worker effect and assess additional materials.

Spatial distribution and determinants of thyroid cancer incidence from 1999 to 2013 in Korea.

We evaluated the spatial variation in thyroid cancer incidence and its determinants in Korea considering its importance in cancer prevention and control. This study was based on the ecological design with cancer incidence data by administrative district from the National Cancer Center and regional characteristics generated from the Korea Community Health Survey Data. We identified spatial clusters of thyroid cancer incidences based on spatial scan statistics. Determinants of regional variation in thyroid cancer incidence were assessed using the Besag-York-Mollie model with integrated nested Laplace approximations. Spatial clusters for low and high thyroid cancer incidences were detected in the northeastern and southwestern regions, respectively. Regional variations in thyroid cancer incidence can be attributed to the prevalence of recipients of basic livelihood security (coefficient, - 1.59; 95% credible interval [CI], - 2.51 to - 0.67), high household income (coefficient, 0.53; 95% CI, 0.31 to 0.76), heavy smoking (coefficient, - 0.91; 95% CI, - 1.59 to - 0.23), thyroid dysfunction (coefficient, 3.24; 95% CI, 1.47 to 5.00), and thyroid cancer screening (coefficient, 0.38; 95% CI, 0.09 to 0.67). This study presented the spatial variations in thyroid cancer incidence, which can be explained by the prevalence of socioeconomic factors, thyroid cancer screening, thyroid dysfunction, and smoking.

Association Between Angiotensin II Receptor Blockers and the Risk of Lung Cancer Among Patients With Hypertension From the Korean National Health Insurance Service-National Health Screening Cohort.

OBJECTIVES: The objective of this study was to estimate the risk of lung cancer in relation to angiotensin II receptor blocker (ARB) use among patients with hypertension from the Korean National Health Insurance Service-National Health Screening Cohort. METHODS: We conducted a retrospective cohort study of patients with hypertension who started to take antihypertensive medications and had a treatment period of at least 6 months. We calculated the weighted hazard ratios (HRs) and their 95% confidence intervals (CIs) of lung cancer associated with ARB use compared with calcium channel blocker (CCB) use using inverse probability treatment weighting. RESULTS: Among a total of 60 469 subjects with a median follow-up time of 7.8 years, 476 cases of lung cancer were identified. ARB use had a protective effect on lung cancer compared with CCB use (HR, 0.75; 95% CI, 0.59 to 0.96). Consistent findings were found in analyses considering patients who changed or discontinued their medication (HR, 0.50; 95% CI, 0.32 to 0.77), as well as for women (HR, 0.56; 95% CI, 0.34 to 0.93), patients without chronic obstructive pulmonary disease (HR, 0.75; 95% CI, 0.56 to 1.00), never-smokers (HR, 0.64; 95% CI, 0.42 to 0.99), and non-drinkers (HR, 0.69; 95% CI, 0.49 to 0.97). In analyses with different comparison antihypertensive medications, the overall protective effects of ARBs on lung cancer risk remained consistent. CONCLUSIONS: The results of the present study suggest that ARBs could decrease the risk of lung cancer. More evidence is needed to establish the causal effect of ARBs on the incidence of lung cancer.

The effect of shifting medical coverage from National Health Insurance to Medical Aid type I and type II on health care utilization and out-of-pocket spending in South Korea.

BACKGROUND: This study examines the effects of a shift in medical coverage, from National Health Insurance (NHI) to Medical Aid (MA), on health care utilization (measured by the number of outpatient visits and length of stay; LOS) and out-of-pocket medical expenses. METHODS: Data were collected from the Korean Welfare Panel Study (2010-2016). A total of 888 MA Type I beneficiaries and 221 MA Type II beneficiaries who shifted from the NHI were included as the case group and 2664 and 663 consecutive NHI holders (1:3 propensity score-matched) were included as the control group, respectively. We used the 'difference-in-differences' (DiD) analysis approach to assess changes in health care utilization and medical spending by the group members. RESULTS: Differential average changes in outpatient visits in the MA Type I panel between the pre- and post-shift periods were significant, but differential changes in LOS were not found. Those who shifted from NHI to MA Type I had increased number of outpatient visits without changes in out-of-pocket spending, compared to consecutive NHI holder who had similar characteristics. However, this was not found for MA Type II beneficiaries. CONCLUSION: Our research provides evidence that the shift in medical coverage from NHI to MA Type I increased the number of outpatient visits without increasing the out-of-pocket spending. Considering the problem of excess medical utilization by Korean MA Type I beneficiaries, further researches are required to have in-depth discussions on the appropriateness of the current cost-sharing level on MA beneficiaries.

Healthcare Costs for Acute Hospitalized and Chronic Heart Failure in South Korea: A Multi-Center Retrospective Cohort Study.

PURPOSE: Although heart failure (HF) is recognized as a leading contributor to healthcare costs and a significant economic burden worldwide, studies of HF-related costs in South Korea are limited. This study aimed to estimate HF-related costs per Korean patient per year and per visit. MATERIALS AND METHODS: This retrospective cohort study analyzed data obtained from six hospitals in South Korea. Patients with HF who experienced ≥one hospitalization or ≥two outpatient visits between January 1, 2013 and December 31, 2013 were included. Patients were followed up for 1 year [in Korean won (KRW)]. RESULTS: Among a total of 500 patients (mean age, 66.1 years; male sex, 54.4%), the mean 1-year HF-related cost per patient was KRW 2,607,173, which included both, outpatient care (KRW 952,863) and inpatient care (KRW 1,654,309). During the post-index period, 22.2% of patients had at least one hospitalization, and their 1-year costs per patient (KRW 8,530,290) were higher than those of patients who had only visited a hospital over a 12-month period (77.8%; KRW 917,029). Among 111 hospitalized patients, the 1-year costs were 1.7-fold greater in patients (n=52) who were admitted to the hospital via the emergency department (ED) than in those (n=59) who were not (KRW 11,040,453 vs. KRW 6,317,942; p<0.001). CONCLUSION: The majority of healthcare costs for HF patients in South Korea was related to hospitalization, especially admissions via the ED. Appropriate treatment strategies including modification of risk factors to prevent or decrease hospitalization are needed to reduce the economic burden on HF patients.

Comparative validity of depression assessment scales for screening poststroke depression.

INTRODUCTION: This study aimed to compare screening properties of four assessment scales for poststroke depression (PSD) at 2 weeks and 1 year after index stroke, and investigated factors contributing to misclassification. METHODS: A total of 423 patients were evaluated 2 weeks after stroke and 288 (68%) were followed 1 year later, and were diagnosed as having major and minor PSD applying DSM-IV criteria gold standards. The Beck Depression Inventory (BDI), Hospital Anxiety and Depression Scale-depression subscale (HADS-D), Hamilton Rating Scale for Depression (HAMD), and Montgomery-Asberg Depression Rating Scale (MADRS) were administered. The balance of sensitivity and specificity was assessed using receiver operating characteristics (ROC) analysis. RESULTS: Discriminating abilities of all the scales for major and all PSD were good (area under ROC values 0.88-0.93 and 0.88-0.92 at 2 weeks; and 0.93-0.96 and 0.89-0.91 at 1 year, respectively). Misclassification was influenced by demographic characteristics and stroke severity particularly for the BDI and HAMD, was more marked for all PSD than for major PSD, and was more prominent at 2 weeks than at 1 year after stroke. LIMITATIONS: Patients with only mild to moderate stroke severity were included. CONCLUSIONS: Although there were no marked differences in the screening abilities for PSD between the scales, differences were found in factors influencing misclassification. Assessment scales with less somatic items may be recommended for the screening of PSD, particularly at the acute phase of stroke.