Challenges in evaluating treatments for COVID-19: The case of in-hospital anticoagulant use and the risk of adverse outcomes.

Anticoagulants are a potential treatment for the thrombotic complications resulting from COVID-19. We aimed to determine the association between anticoagulant use and adverse outcomes among hospitalized patients with COVID-19. We used data from the COVID-19 International Collaborative Research Project in South Korea from January to June 2020. We defined exposure using an intention-to-treat approach, with person-time classified as use or non-use of anticoagulants at cohort entry, and a time-varying approach. The primary outcome was all-cause, in-hospital mortality; the secondary outcome was a composite including respiratory outcomes, cardiovascular outcomes, venous thromboembolism, major bleeding, and intensive care unit admission. Cox proportional hazards models estimated adjusted hazard ratios (HRs) of the outcomes comparing use versus non-use of anticoagulants. Our cohort included 2,677 hospitalized COVID-19 patients, of whom 24 received anticoagulants at cohort entry. Users were older and had more comorbidities. The crude incidence rate (per 1,000 person-days) of mortality was 5.83 (95% CI: 2.80, 10.72) among anticoagulant users and 1.36 (95% CI: 1.14, 1.59) for non-users. Crude rates of the composite outcome were 3.20 (95% CI: 1.04, 7.47) and 1.80 (95% CI: 1.54, 2.08), respectively. Adjusted HRs for mortality (HR: 1.12, 95% CI: 0.48, 2.64) and the composite outcome (HR: 0.79, 95% CI: 0.28, 2.18) were inconclusive. Although our study was not able to draw conclusions on anticoagulant effectiveness for COVID-19 outcomes, these results can contribute to future knowledge syntheses of this important question. Our study demonstrated that the dynamic pandemic environment may have important implications for observational studies of COVID-19 treatment effectiveness.

Association Between Nonsteroidal Antiinflammatory Drug Use and Adverse Clinical Outcomes Among Adults Hospitalized With Coronavirus 2019 in South Korea: A Nationwide Study.

BACKGROUND: Nonsteroidal antiinflammatory drugs (NSAIDs) may exacerbate coronavirus disease 2019 (COVID-19) and worsen associated outcomes by upregulating the enzyme that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to in order to enter cells. METHODS: We conducted a cohort study using South Korea's nationwide healthcare database, which contains data for all individuals who received a COVID-19 test (n = 69 793) as of 8 April 2020. We identified adults hospitalized with COVID-19, where cohort entry was the date of hospitalization. NSAID users were those prescribed NSAIDs in the 7 days before and including cohort entry, and nonusers were those not prescribed NSAIDs during this period. Our primary outcome was a composite of in-hospital death, intensive care unit admission, mechanical ventilation use, and sepsis; our secondary outcomes were cardiovascular complications and acute renal failure. We conducted logistic regression analysis to estimate odds ratio (OR) with 95% confidence intervals (CIs) using inverse probability of treatment weighting to minimize confounding. RESULTS: Of 1824 adults hospitalized with COVID-19 (mean age, 49.0 years; female, 59%), 354 were NSAID users and 1470 were nonusers. Compared with nonuse, NSAID use was associated with increased risks of the primary composite outcome (OR, 1.54; 95% CI, 1.13-2.11) but insignificantly associated with cardiovascular complications (OR, 1.54; 95% CI, 0.96-2.48) or acute renal failure (OR, 1.45; 95% CI, 0.49-4.14). CONCLUSIONS: While awaiting the results of confirmatory studies, we suggest NSAIDs be used with caution for COVID-19 patients as the harms associated with their use may outweigh their benefits.

Socioeconomic disparities in Korea by health insurance type during the COVID-19 pandemic: a nationwide study.

OBJECTIVES: This study explored socioeconomic disparities in Korea using health insurance type as a proxy during the ongoing coronavirus disease 2019 (COVID-19) pandemic. METHODS: We conducted a retrospective cohort study using Korea's nationwide healthcare database, which contained all individuals who received a diagnostic test for COVID-19 (n=232,390) as of May 15, 2020. We classified our cohort by health insurance type into beneficiaries of the National Health Insurance (NHI) or Medicaid programs. Our study outcomes were infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19-related outcomes, a composite of all-cause death, intensive care unit admission, and mechanical ventilation use. We estimated age-, sex-, and Charlson comorbidity index score-adjusted odds ratios (aORs) with 95% confidence intervals (CIs) using a multivariable logistic regression analysis. RESULTS: Of the 218,070 NHI and 14,320 Medicaid beneficiaries who received COVID-19 tests, 7,777 and 738 tested positive, respectively. The Medicaid beneficiaries were older (mean age, 57.5 vs. 47.8 years), more likely to be males (47.2 vs. 40.2%), and had a higher comorbidity burden (mean CCI, 2.0 vs. 1.7) than NHI beneficiaries. Compared to NHI beneficiaries, Medicaid beneficiaries had a 22% increased risk of SARS-CoV-2 infection (aOR, 1.22; 95% CI, 1.09 to 1.38), but had no significantly elevated risk of COVID-19-related outcomes (aOR 1.10, 95% CI 0.77 to 1.57); the individual events of the composite outcome yielded similar findings. CONCLUSIONS: As socioeconomic factors, with health insurance as a proxy, could serve as determinants during the current pandemic, pre-emptive support is needed for high-risk groups to slow its spread.