Statin Use and COVID-19 Infectivity and Severity in South Korea: Two Population-Based Nationwide Cohort Studies.

Background: Basic studies suggest that statins as add-on therapy may benefit patients with COVID-19; however, real-world evidence of such a beneficial association is lacking.

Objective: We investigated differences in SARS-CoV-2 test positivity and clinical outcomes of COVID-19 (composite endpoint: admission to intensive care unit, invasive ventilation, or death) between statin users and nonusers.

Methods: Two independent population-based cohorts were analyzed, and we investigated the differences in SARS-CoV-2 test positivity and severe clinical outcomes of COVID-19, such as admission to the intensive care unit, invasive ventilation, or death, between statin users and nonusers.

Physical activity and the risk of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related mortality in South Korea: a nationwide cohort study.

Purpose: To determine the potential associations between physical activity and risk of SARS-CoV-2 infection, severe illness from COVID-19 and COVID-19 related death using a nationwide cohort from South Korea.

Methods: Data regarding 212 768 Korean adults (age ≥20 years), who tested for SARS-CoV-2, from 1 January 2020 to 30 May 2020, were obtained from the National Health Insurance Service of South Korea and further linked with the national general health examination from 1 January 2018 to 31 December 2019 to assess physical activity levels. SARS-CoV-2 positivity, severe COVID-19 illness and COVID-19 related death were the main outcomes.

Autoimmune inflammatory rheumatic diseases and COVID-19 outcomes in South Korea: a nationwide cohort study.

Background: Real-world evidence on the association between autoimmune inflammatory rheumatic diseases, therapies related to these diseases, and COVID-19 outcomes are inconsistent. We aimed to investigate the potential association between autoimmune inflammatory rheumatic diseases and COVID-19 early in the COVID-19 pandemic.

Methods: We did an exposure-driven, propensity score-matched study using a South Korean nationwide cohort linked to general health examination records.

COVID-19 Morbidity and Severity in Patients With Age-Related Macular Degeneration: A Korean Nationwide Cohort Study.

Purpose: To determine the potential association between age-related macular degeneration (AMD), a representative chronic age-related degenerative disease of the retina associated with inflammation and aging, and susceptibility to SARS-CoV-2 infection and severe COVID-19 outcomes.

Design: Nationwide cohort study with propensity-score matching.

Methods: A population-based nationwide cohort in Korea was examined.

Estimating COVID-19 Infection and Severity Risks in Patients with Chronic Rhinosinusitis: A Korean Nationwide Cohort Study.

Background: Basic studies suggest that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can affect chronic rhinosinusitis (CRS), but there is unclear real-world evidence regarding the association of underlying CRS with the risk for SARS-CoV-2 infection and severe coronavirus disease 19 (COVID-19).

Objective: We aimed to determine whether CRS is associated with increased risk for SARS-CoV-2 infection and severe COVID-19.

Methods: Altogether, 219,959 adult patients who tested for SARS-CoV-2 in South Korea from January 1 to May 15, 2020 (excluding self-referral) were identified in this nested case-control study with propensity score matching.

Association between mental illness and COVID-19 susceptibility and clinical outcomes in South Korea: a nationwide cohort study.

Background: Evidence for the associations between mental illness and the likelihood of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result and the clinical outcomes of COVID-19 is scarce. We aimed to investigate these associations with data from a national register in South Korea.

Methods: A nationwide cohort study with propensity score matching was done in South Korea using data collected from the Health Insurance Review and Assessment Service of Korea.

Allergic disorders and susceptibility to and severity of COVID-19: A nationwide cohort study.

Background: There is inconclusive and controversial evidence of the association between allergic diseases and the risk of adverse clinical outcomes of coronavirus disease 2019 (COVID-19).

Objective: We sought to determine the association of allergic disorders with the likelihood of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result and with clinical outcomes of COVID-19 (admission to intensive care unit, administration of invasive ventilation, and death).

Methods: A propensity-score-matched nationwide cohort study was performed in South Korea.

Severe clinical outcomes of COVID-19 associated with proton pump inhibitors: a nationwide cohort study with propensity score matching.

Objective: The adverse effects of proton pump inhibitors (PPIs) have been documented for pneumonia; however, there is no consensus regarding whether the use of PPIs might be harmful regarding the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this regard, we aimed to measure the potential associations of the current use of PPIs with the infection rates of COVID-19 among patients who underwent SARS-CoV-2 testing.

Design: Data were derived from a Korean nationwide cohort study with propensity score matching.