Background: Cancer patients have an increased risk of cardiovascular outcomes and are susceptible to coronavirus disease 2019 (COVID-19) infection. We aimed to assess the cardiovascular safety of COVID-19 vaccination for cancer patients in South Korea. Methods: We conducted a self-controlled case series study using the K-COV-N cohort (2018– 2021). Patients with cancer aged 12 years or older who experienced cardiovascular outcomes were identified. Cardiovascular outcomes were defined as myocardial infarction, stroke, venous thromboembolism (VTE), myocarditis, or pericarditis, and the risk period was 0–28 days after receiving each dose of COVID-19 vaccines. A conditional Poisson regression model was used to calculate the incidence rate ratio (IRR) with 95% confidence interval (CI). Results: Among 318,105 patients with cancer, 4,754 patients with cardiovascular outcomes were included. The overall cardiovascular risk was not increased (adjusted IRR, 0.99 [95% CI, 0.90–1.08]) during the whole risk period. The adjusted IRRs of total cardiovascular outcomes during the whole risk period according to the vaccine type were 1.07 (95% CI, 0.95–1.21) in the mRNA vaccine subgroup, 0.99 (95% CI, 0.83–1.19) in the ChAdOx1 nCoV-19 vaccine subgroup, and 0.86 (95% CI, 0.68–1.10) in the mix-matched vaccination subgroup. However, in the analysis of individual outcome, the adjusted IRR of myocarditis was increased to 11.71 (95% CI, 5.88–23.35) during the whole risk period. In contrast, no increased risk was observed for other outcomes, such as myocardial infarction, stroke, VTE, and pericarditis. Conclusion For cancer patients, COVID-19 vaccination demonstrated an overall safe profile in terms of cardiovascular outcomes. However, caution is required as an increased risk of myocarditis following COVID-19 vaccination was observed in this study.

Purpose: Nivolumab and regorafenib are second-line therapies for patients with advanced hepatocellular carcinoma (HCC). We aimed to compare the effectiveness of nivolumab and regorafenib. Materials and Methods: We retrospectively reviewed patients with HCC treated with nivolumab or regorafenib after sorafenib failure. Progression-free survival (PFS) and overall survival (OS) were analyzed. An inverse probability of treatment weighting using the propensity score (PS) was performed to reduce treatment selection bias. Results: Among the 189 patients recruited, 137 and 52 patients received regorafenib and nivolumab after sorafenib failure, respectively. Nivolumab users showed higher Child-Pugh B patients (42.3% vs. 24.1%) and shorter median sorafenib maintenance (2.2 months vs. 3.5 months) compared to regorafenib users. Nivolumab users showed shorter median OS (4.2 months vs. 7.4 months, p=0.045) than regorafenib users and similar median PFS (1.8 months vs. 2.7 months, p=0.070). However, the median overall and PFS did not differ between the two treatment groups after the 1:1 PS matching (log-rank p=0.810 and 0.810, respectively) and after the stabilized inverse probability of treatment weighting (log-rank p=0.445 and 0.878, respectively). In addition, covariate-adjusted Cox regression analyses showed that overall and PFS did not significantly differ between nivolumab and regorafenib users after 1:1 PS matching and stabilized inverse probability of treatment weighting (all p>0.05). Conclusion Clinical outcomes of patients treated with nivolumab and regorafenib after sorafenib treatment failure did not differ significantly.

Background: and Purpose There have been few reports on recent trends in the occurrence of epilepsy. The aim of this study was to estimate the incidence and prevalence of epilepsy and analyze their annual trends in Korea over the period 2009–2017. Methods: This nationwide population-based study was carried out using the National Health Insurance Service of Korea database. A prevalent case was defined as one of a patient receiving a prescription of anticonvulsants under the diagnostic codes for epilepsy or seizure. An incident case was ascertained by confirming the absence of any epilepsy-related diagnostic codes and anticonvulsant prescription for 2 years or more before the operational definition for a prevalent case was met. Alternative operational definitions for epilepsy were tested. The temporal trends of the incidence and prevalence of epilepsy were analyzed using a Poisson regression model, and are expressed as average annual percentage changes (AAPCs). Results: The incidence of epilepsy increased from 28.7/100,000 persons in 2009 to 35.4/100,000 persons in 2017. The prevalence increased gradually from 3.4/1,000 persons in 2009 to 4.8/1,000 persons in 2017. These increasing trends were more evident among elderly subjects aged ≥75 years and in those who had codes for epilepsy or seizure as an additional diagnosis. Age standardization revealed a less prominent but still increasing trend in both incidence (AAPC=0.48%) and prevalence (AAPC=3.11%). Conclusions There have been increasing trends in both the prevalence and incidence of epilepsy in Korea between 2009 and 2017. This finding appears to be related to societal aging and the high incidence of symptomatic epilepsy in the elderly population.

OBJECTIVES: Recent evidence has shown no harm associated with the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin-receptor blockers (ARBs) in patients with coronavirus disease 2019 (COVID-19). We sought to further clarify the possible association between ACEI/ARB use and the risk of poor clinical outcomes of COVID-19. METHODS: From the completely enumerated COVID-19 cohort in Korea, we identified 1,290 patients with hypertension, of whom 682 had and 603 did not have records of ACEI/ARB use during the 30-day period before their COVID-19 diagnosis. Our primary endpoint comprised clinical outcomes, including all-cause mortality, use of mechanical ventilation, intensive care unit admission, and sepsis. We used inverse probability of treatment weighting (IPTW) to mitigate selection bias, and a Poisson regression model to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for comparing outcomes between ACEI/ARB users and non-users. RESULTS: Compared to non-use, ACEI/ARB use was associated with lower clinical outcomes (IPTW-adjusted RR, 0.60; 95% CI, 0.42 to 0.85; p=0.005). For individual outcomes, ACEI/ARB use was not associated with all-cause mortality (IPTW-adjusted RR, 0.62; 95% CI, 0.35 to 1.09; p=0.097) or respiratory events (IPTW-adjusted RR, 0.99; 95% CI, 0.84 to 1.17; p=0.904). Subgroup analysis showed a trend toward a protective role of ACEIs and ARBs against overall outcomes in men (IPTW-adjusted RR, 0.84; 95% CI, 0.69 to 1.03; pinteraction=0.008) and patients with pre-existing respiratory disease (IPTW-adjusted RR, 0.74; 95% CI, 0.60 to 0.92; pinteraction=0.002). CONCLUSIONS We present clinical evidence to support continuing ACE/ARB use in COVID-19 patients with hypertension based on the completely enumerated Korean cohort.

Background: and Purpose There have been few reports on recent trends in the occurrence of epilepsy. The aim of this study was to estimate the incidence and prevalence of epilepsy and analyze their annual trends in Korea over the period 2009–2017. Methods: This nationwide population-based study was carried out using the National Health Insurance Service of Korea database. A prevalent case was defined as one of a patient receiving a prescription of anticonvulsants under the diagnostic codes for epilepsy or seizure. An incident case was ascertained by confirming the absence of any epilepsy-related diagnostic codes and anticonvulsant prescription for 2 years or more before the operational definition for a prevalent case was met. Alternative operational definitions for epilepsy were tested. The temporal trends of the incidence and prevalence of epilepsy were analyzed using a Poisson regression model, and are expressed as average annual percentage changes (AAPCs). Results: The incidence of epilepsy increased from 28.7/100,000 persons in 2009 to 35.4/100,000 persons in 2017. The prevalence increased gradually from 3.4/1,000 persons in 2009 to 4.8/1,000 persons in 2017. These increasing trends were more evident among elderly subjects aged ≥75 years and in those who had codes for epilepsy or seizure as an additional diagnosis. Age standardization revealed a less prominent but still increasing trend in both incidence (AAPC=0.48%) and prevalence (AAPC=3.11%). Conclusions There have been increasing trends in both the prevalence and incidence of epilepsy in Korea between 2009 and 2017. This finding appears to be related to societal aging and the high incidence of symptomatic epilepsy in the elderly population.

OBJECTIVES: Recent evidence has shown no harm associated with the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin-receptor blockers (ARBs) in patients with coronavirus disease 2019 (COVID-19). We sought to further clarify the possible association between ACEI/ARB use and the risk of poor clinical outcomes of COVID-19. METHODS: From the completely enumerated COVID-19 cohort in Korea, we identified 1,290 patients with hypertension, of whom 682 had and 603 did not have records of ACEI/ARB use during the 30-day period before their COVID-19 diagnosis. Our primary endpoint comprised clinical outcomes, including all-cause mortality, use of mechanical ventilation, intensive care unit admission, and sepsis. We used inverse probability of treatment weighting (IPTW) to mitigate selection bias, and a Poisson regression model to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for comparing outcomes between ACEI/ARB users and non-users. RESULTS: Compared to non-use, ACEI/ARB use was associated with lower clinical outcomes (IPTW-adjusted RR, 0.60; 95% CI, 0.42 to 0.85; p=0.005). For individual outcomes, ACEI/ARB use was not associated with all-cause mortality (IPTW-adjusted RR, 0.62; 95% CI, 0.35 to 1.09; p=0.097) or respiratory events (IPTW-adjusted RR, 0.99; 95% CI, 0.84 to 1.17; p=0.904). Subgroup analysis showed a trend toward a protective role of ACEIs and ARBs against overall outcomes in men (IPTW-adjusted RR, 0.84; 95% CI, 0.69 to 1.03; pinteraction=0.008) and patients with pre-existing respiratory disease (IPTW-adjusted RR, 0.74; 95% CI, 0.60 to 0.92; pinteraction=0.002). CONCLUSIONS We present clinical evidence to support continuing ACE/ARB use in COVID-19 patients with hypertension based on the completely enumerated Korean cohort.

Objective: The association between benzodiazepine use and the risk of cognitive impairment or dementia has been controversial. Our study aims to detect this association through a caseon-case method using the Korea Institute of Drug Safety & Risk Management-Korea adverse event reporting system database (KIDS-KD) between 2007 and 2016. Methods: Cases were adverse event (AE)-pairs with suspected cognitive impairment or dementia. 10 non-cases were matched to each case on age and sex. Exposure was defined as use of benzodiazepines, including long-, intermediate-, and short-acting benzodiazepine. We conducted multivariable logistic regression analyses to estimate reporting odds ratios (ROR) and 95% confidence intervals (CI). Results: Of the 1,086,584 AE-pairs, 887 cases were suspected AE-pairs of cognitive impairment or dementia, and 775,444 non-cases were selected. Benzodiazepine use was associated with increased AE-pairs of cognitive impairment or dementia when assessed using those with certain, probable, and/or possible in causality assessments (ROR=2.69, 95% CI=1.66–4.38). Higher ROR estimates were shown in female (2.33, 1.48–3.67) and in those with polypharmacy (2.20, 1.35–3.57). Dementia safety profiles were inconsistent across individual benzodiazepine components. Conclusion These results suggest the potentially increased association between benzodiazepine use and cognitive impairment or dementia in female and those with polypharmacy. Inconsistent safety profiles of benzodiazepine components should be further investigated.

Purpose: Vaccine hesitancy is among the top ten threats to global health, and access to precise data on adverse events following immunization (AEFIs) is imperative to alleviate public concerns surrounding vaccines. This study aimed to present the overall trends of AEFIs reported in South Korea. Materials and Methods: We evaluated the trends of AEFIs using the Korea Institute of Drug Safety & Risk Management-Korea Adverse Event Reporting System database between January 2005 and December 2017. AEFIs were classified into five categories to evaluate associations between vaccines and AEFIs through a case-non-case study: neurologic reactions, general systemic reactions, local reactions, allergic reactions, and others. Results: Among 54378 reported adverse events (AEs) associated with all vaccines approved in South Korea, more than half (56.7%) occurred following influenza vaccination, followed by the pneumococcal (11.6%) and Bacillus Calmette-Guérin (BCG) vaccines (5.0%). After immunization with most vaccines, general systemic reactions were most common, followed by local and neurologic reactions. Adjusted reporting odds ratios were calculated for all neurologic, general, local, and allergic reactions: of all vaccines, rotavirus [neurologic 2.43, 95% confidence interval (CI), 2.25–2.62], BCG (general; 2.20, 95% CI, 1.91–2.53), BCG (local; 3.15, 95% CI, 2.69–3.68), and Japanese encephalitis (allergic 2.38, 95% CI, 1.98–2.87) vaccines showed the highest values. Conclusion The majority of reported AEFIs were non-serious and mostly general systemic reactions. Sufficient knowledge on the AEFIs would secure public confidence on the safety of vaccines, thereby reducing public health burden from vaccine-preventable diseases.