Clinical Epidemiology of Hospitalized Patients With Coronavirus Disease 2019 (COVID-19) in Japan: Report of the COVID-19 Registry Japan

Clinical clustering with prognostic implications in Japanese COVID-19 patients: report from Japan COVID-19 Task Force, a nation-wide consortium to investigate COVID-19 host genetics

Background

The clinical course of coronavirus disease (COVID-19) is diverse, and the usefulness of phenotyping in predicting the severity or prognosis of the disease has been demonstrated overseas. This study aimed to investigate clinically meaningful phenotypes in Japanese COVID-19 patients using cluster analysis.

Methods

From April 2020 to May 2021, data from inpatients aged ≥ 18 years diagnosed with COVID-19 and who agreed to participate in the study were collected. A total of 1322 Japanese patients were included. Hierarchical cluster analysis was performed using variables reported to be associated with COVID-19 severity or prognosis, namely, age, sex, obesity, smoking history, hypertension, diabetes mellitus, malignancy, chronic obstructive pulmonary disease, hyperuricemia, cardiovascular disease, chronic liver disease, and chronic kidney disease.

Results

Participants were divided into four clusters: Cluster 1, young healthy (n = 266, 20.1%); Cluster 2, middle-aged (n = 245, 18.5%); Cluster 3, middle-aged obese (n = 435, 32.9%); and Cluster 4, elderly (n = 376, 28.4%). In Clusters 3 and 4, sore throat, dysosmia, and dysgeusia tended to be less frequent, while shortness of breath was more frequent. Serum lactate dehydrogenase, ferritin, KL-6, d-dimer, and C-reactive protein levels tended to be higher in Clusters 3 and 4. Although Cluster 3 had a similar age as Cluster 2, it tended to have poorer outcomes. Both Clusters 3 and 4 tended to exhibit higher rates of oxygen supplementation, intensive care unit admission, and mechanical ventilation, but the mortality rate tended to be lower in Cluster 3.

Conclusions

We have successfully performed the first phenotyping of COVID-19 patients in Japan, which is clinically useful in predicting important outcomes, despite the simplicity of the cluster analysis method that does not use complex variables.

Comparison of clinical characteristics of COVID-19 in pregnant women between the Delta and Omicron variants of concern predominant periods

Background

Information regarding effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant strains on clinical manifestations and outcomes of coronavirus disease 2019 (COVID-19) in pregnant women is limited.

Methods

A retrospective observational study was conducted using the data from the nationwide COVID-19 registry in Japan. We identified pregnant patients with symptomatic COVID-19 hospitalized during the study period. The Delta and Omicron variants of concern (VOC) predominant periods were defined as August 1 to December 31, 2021 and January 1 to May 31, 2022, respectively. Clinical characteristics were compared between the patients in the Delta and Omicron VOC periods. In addition, logistic regression analysis was performed to identify risk factors for developing moderate-to-severe COVID-19.

Results

During the study period, 310 symptomatic COVID-19 cases of pregnant women were identified; 111 and 199 patients were hospitalized during the Delta and Omicron VOC periods, respectively. Runny nose and sore throat were more common, and fatigue, dysgeusia, and olfactory dysfunction were less common manifestations observed in the Omicron VOC period. In the multivariable logistic regression analysis, onset during the later stage of pregnancy (OR: 2.08 [1.24–3.71]) and onset during the Delta VOC period (OR: 2.25 [1.08–4.90]) were independently associated with moderate-to-severe COVID-19, whereas two doses of SARS-CoV-2 vaccine were protective against developing moderate-to-severe COVID-19 (OR: 0.34 [0.13–0.84]).

Conclusions

Clinical manifestations of COVID-19 in pregnant women differed between the Delta and Omicron VOC periods. SARS-CoV-2 vaccination was still effective in preventing severe COVID-19 throughout the Delta and Omicron VOC periods.

Activity of daily life dependency predicts the risk of mortality in patients with COVID-19 undergoing hemodialysis: a retrospective analysis of a single center with nosocomial outbreak

Background

We experienced a nosocomial outbreak of coronavirus disease 2019 (COVID-19) from November 2020 to February 2021, during the third wave of the pandemic in Japan.

Methods

We retrospectively assessed the characteristics and data of 20 inpatients undergoing hemodialysis who were hospitalized for treatment of diseases other than COVID-19 during the COVID-19 nosocomial outbreak (“inpatient,” IP), and of 10 outpatients undergoing hemodialysis who were hospitalized for the care of COVID-19 under outpatient visits (“outpatient,” OP).

Results

Eleven patients in the IP group (55%) and one in the OP group (10%) died. Kaplan–Meier analysis showed that the IP group died more rapidly than the OP group (p = 0.02). Multivariate analysis among all hemodialysis patients showed that the IP group was not at risk of mortality independently; however, the activity of daily life (ADL) dependency was found to be an independent factor in increasing the risk of mortality (hazard ratio: 7.618).

Conclusion

Our findings show that the nosocomial infected group has a worse prognosis, although it is not an independent predictor for the risk of mortality. ADL dependency could predict the risk of mortality in all hemodialysis patients with COVID-19 during the third wave pandemic in Japan.

Risk factors for hospitalization or mortality for COVID-19 in patients with rheumatic diseases: Results of a nation-wide JCR COVID-19 registry in Japan

BACKGROUND

The incidence and prognosis of COVID-19 and rheumatic disease vary among ethnicities and regions. COVID-19 outcomes in rheumatic disease patients remain unclear, especially in the Asia-Pacific region. This study aimed to clarify the demographic and clinical factors that may influence COVID-19 prognosis in rheumatic disease patients.

METHODS

This was a case series of patients registered with the COVID-19 national registry of Japan College of Rheumatology between June 3, 2020, and June 30, 2021. Multivariable logistic regression was used to estimate the risk of hospitalization or death. Age, sex, smoking status, rheumatic disease diagnosis, comorbidities, and rheumatic disease medications are taken immediately before infection was analyzed.

RESULTS

A total of 220 patients from 55 institutions in Japan were included in the study, among whom 186 (84.5%) were hospitalized and 11 (5.0%) died. COVID-19 treatments were provided to 126 patients (57.3%), and mainly comprised glucocorticoids, favipiravir, remdesivir, and tocilizumab. In the multiple logistic regression model, older age and a history of hypertension were associated with hospitalization, while older age was associated with mortality. No specific treatment was correlated with mortality or hospitalization by the multi-variate analysis.

CONCLUSIONS

Older age and hypertension were associated with a poor prognosis in Japanese COVID-19 patients with CTD. Factors not directly related to CTD were closely associated with the prognosis.

Effect of COVID-19 inpatients with cognitive decline on discharge after the quarantine period: A retrospective cohort study

Background

A new SARS-CoV-2 variant, Omicron, was reported on November 14, 2021, and it altered the COVID-19 epidemic with a different peak timing by region in Japan. Residents in the Hiroshima prefecture, especially the vulnerable elderly, were threatened by this wave in advance of many other prefectures. We evaluated the effect of cognitive decline on discharge extension after the quarantine period.

Methods

Participants of this retrospective cohort study were patients who were admitted to the care unit for COVID-19 treatment at Hiroshima University Hospital between January 1, 2022, and March 1, 2022 (60 days). Our primary outcome was the extended length of stay (LOS) in the hospital after the quarantine period (10 days after onset). A negative binomial regression analysis was performed to assess the extended LOS of patients with cognitive decline, adjusting for age classification, gender, and severity of COVID-19.

Results

The total number of participants was 74. Per the level of cognitive function, there were 56 independent participants, 5 mild declines, and 13 severe declines. For the negative binomial regression analysis, the exponentiated coefficient of mild cognitive decline was 3.05 (95% confidential interval [CI]: 1.43-6.49) and that of severe cognitive decline was 1.95 (95% CI: 1.09-3.53).

Conclusions

Mild cognitive decline and severe cognitive decline elevated the risk of extended LOS after COVID-19 patients finished the quarantine period.

Evaluation of the representativeness of data in the COVID-19 Registry Japan during the first six waves of the epidemic

The COVID-19 Registry Japan (COVIREGI-JP), a registry of patients hospitalized with coronavirus disease (COVID-19), contains the largest national COVID-19 inpatient population. Since COVIREGI-JP invites voluntary participation by facilities, selection bias is inevitable. The current study examined the representativeness of COVIREGI-JP data in comparison to open-source national data. The number of infections and deaths among hospitalized COVID-19 patients in COVIREGI-JP were compared to those in national data recorded during the six waves of the COVID-19 epidemic until March 6, 2022. During the period studied, patients in COVIREGI-JP represented 1% of the total COVID-19 cases according to national data; the proportion was high during the first wave (32.7%) and tended to decrease, especially after the fourth wave. The overall proportion of patients from each region varied from 0.8% to 2.5%, but case fatality rates in COVIREGI-JP tended to be higher than those in the national data, with the exception of a few waves, in several regions. The difference was smallest during the first wave. Although COVIREGI-JP consistently registered cases from all regions of the country, the proportion tended to decline after the beginning of the epidemic. Given the epidemiological persistence and the ever-changing epidemiology of COVID-19, continued case registration and data utilization in COVIREGI-JP is desirable, although selection bias in COVIREGI-JP registration of cases should be carefully interpreted.

Clinical characteristics of patients with COVID-19 admitted to the COVID-19 Emergency Field Hospital of Bangkalan, Indonesia

Background: Following the surge of coronavirus disease 2019 (COVID-19) cases in the epicenter of East Java Province, this study aimed to determine the clinical characteristics of patients with COVID-19 at one of the emergency field hospitals in Indonesia.

Methods: This was a single-centered, retrospective descriptive study of 763 patients admitted to the COVID-19 Emergency Field Hospital of Bangkalan from July 5 2021 to September 30 2021. The demographic data, clinical signs and symptoms, pre-existing comorbidities, therapy, and clinical outcomes of the patients were analyzed using SPSS.

Results: The clinical characteristics of patients with COVID-19 at the emergency hospital were varied. A total of 763 patients were included. The most common age was between 40 and 49 years (31.1%), a slight majority were women (51.5%), and most had travelled abroad in the last 14 days (99.1%). Of the 763 patients, 70.9% had no comorbidities. Half of the patients were asymptomatic (49.4%), 46% were mild cases, 4.1% were moderate, and 0.5% severe. The most common symptoms were productive cough (15.7%) and headache (15.3%). Supportive and comorbidity therapy were given which showed excellent clinical outcomes.

Conclusions: This study presents the description of the clinical characteristics of COVID-19 patients during high surge cases of COVID-19 that are mostly dominated by Indonesian migrant workers in a field hospital. majority of COVID-19 patients were asymptomatic and therapy without antibiotics or antivirals showed positive outcomes in COVID-19 patients.

Comparison of COVID-19 pneumonia during the SARS-CoV-2 Omicron wave and the previous non-Omicron wave in a single facility

BACKGROUND

The characteristics of coronavirus disease 2019 (COVID-19) pneumonia caused by the severe acute respiratory syndrome coronavirus 2 Omicron variant have not been fully described. Unlike other variants, the Omicron variant replicates rapidly in the bronchus. Therefore, we hypothesized that it would have different computed tomography (CT) findings from non-Omicron variants.

METHODS

We enrolled patients with COVID-19 who visited our hospital and underwent chest CT during the first month of the Omicron wave (January 2022; N = 231) and the previous non-Omicron wave (July 2021; N = 87). We retrospectively evaluated the differences in the prevalence rate and CT characteristics of COVID-19 pneumonia between the two waves.

RESULTS

The prevalence of pneumonia was significantly lower in the Omicron wave group (79/231, 34.2%) compared to the previous wave group (67/87, 77.0%) (P < 0.001). For the predominant distribution pattern of pneumonia, the Omicron wave group revealed a significantly lower rate of the peripheral pattern and a higher rate of the random pattern than the previous wave group. In addition, the Omicron wave group had a significantly lower rate of consolidation than the previous wave group. The ground-glass opacities (GGOs) rate was similar between the two wave groups. For GGOs patterns, cluster-like GGOs along the bronchi on chest CT were more frequently observed during the Omicron wave than during the previous wave.

CONCLUSION

The Omicron wave group had a lower COVID-19 pneumonia prevalence than the previous wave group. Cluster-like GGOs should be noted as a characteristic CT finding of pneumonia during the Omicron wave.

Impact of long-COVID on health-related quality of life in Japanese COVID-19 patients

Background

The empirical basis for a quantitative assessment of the disease burden imposed by long-COVID is currently scant. We aimed to inform the disease burden caused by long-COVID in Japan.

Methods

We conducted a cross sectional self-report questionnaire survey. The questionnaire was mailed to 526 eligible patients, who were recovered from acute COVID-19 in April 2021. Answers were classified into two groups; participants who have no symptom and those who have any ongoing prolonged symptoms that lasted longer than four weeks at the time of the survey. We estimated the average treatment effect (ATE) of ongoing prolonged symptoms on EQ-VAS and EQ-5D-3L questionnaire using inverse probability weighting. In addition to symptom prolongation, we investigated whether other factors (including demography, lifestyle, and acute severity) were associated with low EQ-VAS and EQ-5D-3L values, by multivariable linear regression.

Results

349 participants reported no symptoms and 108 reported any symptoms at the time of the survey. The participants who reported any symptoms showed a lower average value on the EQ-VAS (69.9 vs 82.8, respectively) and on the EQ-5D-3L (0.85 vs 0.96, respectively) than those reporting no symptoms considering the ATE of ongoing prolonged symptoms. The ATE of ongoing prolonged symptoms on EQ-VAS was − 12.9 [95% CI − 15.9 to − 9.8], and on the EQ-5D-3L it was − 0.11 [95% CI − 0.13 to − 0.09], implying prolonged symptoms have a negative impact on patients’ EQ-VAS and EQ-5D-3L score. In multivariable linear regression, only having prolonged symptoms was associated with lower scores (− 11.7 [95% CI − 15.0 to − 8.5] for EQ-VAS and − 0.10 [95% CI − 0.13 to − 0.08] for EQ-5D-3L).

Conclusions

Due to their long duration, long-COVID symptoms represent a substantial disease burden expressed in impact on health-related quality of life.

Incidence of thromboembolic complications in hospitalized COVID-19 patients in a medical ward in Japan: A single-center retrospective and prospective observational study

BACKGROUND

A high incidence of thromboembolic complications is one of the hallmarks of COVID-19. However, there may be a difference in the incidence of thromboembolic complications between Asian and Western people. In addition, few prospective studies have been conducted to determine the incidence of thromboembolic complications in hospitalized COVID-19 patients in medical wards in Japan.

METHODS

A single-center retrospective and prospective cohort study was conducted to determine the incidence of thromboembolic complications in symptomatic COVID-19 patients in a medical ward in a Japanese hospital. All 1116 consecutive COVID-19 patients who were admitted to our hospital from November 1, 2020, to October 26, 2021, were included. The primary outcome was any thromboembolic complications, which included venous thromboembolism, myocardial infarction, ischemic stroke, and other arterial embolisms.

RESULTS

The median patient age was 50 (IQR, 37-61), 402 (36.0%) were women, 1005 (90.1%) were Japanese, the median body mass index was 24.1 (IQR, 21.6-27.2), and 43 (3.9%) had Padua scores of at least 4 points at admission. Regarding the severity of COVID-19, 543 (48.7%), 315 (28.2%), 204 (18.3%), and 54 (4.8%) patients had mild, moderate, severe, and critical COVID-19, respectively. Nine patients (0.8%) died, and 47 patients (4.2%) were transferred to other hospitals for intensive care. The primary outcome occurred in only 5 patients (0.5%; 95% CI, 0.1-0.8) and consisted of 3 ischemic strokes, 2 limb ischemia events, and one asymptomatic pulmonary embolism. Even in the 204 patients with severe COVID-19, the prevalence of thromboembolic complications was only 2.5% (95% CI, 0.3-4.6).

CONCLUSION

Thromboembolic complications of COVID-19 are rare even in severe cases in a medical ward in a Japanese hospital. Further studies are needed to identify severe COVID-19 patients with a higher risk for thromboembolic complications in Japan.

Clinical characteristics of COVID-19 in hospitalized children during the Omicron variant predominant period

Introduction

Information regarding the clinical manifestations and outcomes of coronavirus disease 2019 (COVID-19) in children under the Omicron variant predominant period is still limited.

Methods

A nationwide retrospective cohort study was conducted. Pediatric COVID-19 patients (<18 years of age) hospitalized between August 1, 2021 and March 31, 2022 were enrolled. Epidemiological and clinical characteristics between the Delta variant predominant period (August 1 to December 31, 2021) and the Omicron variant predominant period (January 1 to March 31, 2022) were compared.

Results

During the study period, 458 cases in the Delta predominant period and 389 cases in the Omicron predominant period were identified. Median age was younger (6.0 vs. 8.0 years, P = 0.004) and underlying diseases were more common (n = 65, 16.7% vs. n = 53, 11.6%) in the Omicron predominant period than those in the Delta variant predominant era. For clinical manifestations, fever ≥38.0 °C at 2 to <13 years old, sore throat at ≥ 13 years, and seizures at 2 to <13 years old were more commonly observed, and dysgeusia and olfactory dysfunction at ≥ 6 years old were less commonly observed in the Omicron variant predominant period. The number of patients requiring noninvasive oxygen support was higher in the Omicron predominant period than that in the Delta predominant period; however, intensive care unit admission rates were similar and no patients died in both periods.

Conclusions

In the Omicron variant predominant period, more pediatric COVID-19 patients experienced fever and seizures, although the overall outcomes were still favorable.

Predictive value of neutrophil-to-lymphocyte ratio for the fatality of COVID-19 patients complicated with cardiovascular diseases and/or risk factors

Previous studies have reported that a high neutrophil-to-lymphocyte ratio (NLR) is associated with disease severity and poor prognosis in COVID-19 patients. We aimed to investigate the clinical implications of NLR in patients with COVID-19 complicated with cardiovascular diseases and/or its risk factors (CVDRF). In total, 601 patients with known NLR values were selected from the CLAVIS-COVID registry for analysis. Patients were categorized into quartiles (Q1, Q2, Q3, and Q4) according to baseline NLR values, and demographic and clinical parameters were compared between the groups. Survival analysis was conducted using the Kaplan-Meier method. The diagnostic performance of the baseline and follow-up NLR values was tested using receiver operating characteristic (ROC) curve analysis. Finally, two-dimensional mapping of patient characteristics was conducted using t-stochastic neighborhood embedding (t-SNE). In-hospital mortality significantly increased with an increase in the baseline NLR quartile (Q1 6.3%, Q2 11.0%, Q3 20.5%; and Q4, 26.6%; p < 0.001). The cumulative mortality increased as the quartile of the baseline NLR increased. The paired log-rank test revealed significant differences in survival for Q1 vs. Q3 (p = 0.017), Q1 vs. Q4 (p < 0.001), Q2 vs. Q3 (p = 0.034), and Q2 vs. Q4 (p < 0.001). However, baseline NLR was not identified as an independent prognostic factor using a multivariate Cox proportional hazards regression model. The area under the curve for predicting in-hospital death based on baseline NLR was only 0.682, whereas that of follow-up NLR was 0.893. The two-dimensional patient map with t-SNE showed a cluster characterized by high mortality with high NLR at follow-up, but these did not necessarily overlap with the population with high NLR at baseline. NLR may have prognostic implications in hospitalized COVID-19 patients with CVDRF, but its significance depends on the timing of data collection.

Soluble angiotensin-converting enzyme 2 association with lipid metabolism

Increased expression of angiotensin-converting enzyme 2 (ACE2) is one of the likely explanations for disease severity in patients with coronavirus disease 2019 (COVID-19). In this study, we aimed to test whether soluble ACE2 (sACE2) levels are correlated to known risk factors of severe COVID-19 including biochemical parameters, body mass index and smoking habits. We cross-sectionally evaluated serum sACE2 levels in obese or tobacco-smoking populations and compared them to those in non-obese and non-smoking healthy participants. Additionally, fibroblast growth factor-21 (FGF21) was investigated as a candidate regulator of sACE2. A total of 220 male participants aged 30–59 years undergoing an annual health checkup were enrolled in this study: 59 obese, 80 smokers, and 81 healthy. Serum sACE2 levels were significantly higher in obese participants but not in tobacco-smoking participants when compared to healthy participants. sACE2 levels were significantly correlated with total cholesterol and triglycerides but not with body mass index. Furthermore, no regulatory relationship was found between FGF21 and sACE2. Lipid metabolism disorders accompanied by upregulation of serum sACE2 may be underlying mechanisms of COVID-19 aggravation and might be a novel breakthrough treatment target.

Adverse reactions to mRNA coronavirus disease 2019 (COVID-19) vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 576 medical staff

OBJECTIVES

Various measures have been taken to curb the COVID-19 epidemic, but their effect has been limited. Vaccines are expected to make a definite improvement. In Japan, vaccination began in February 2021. However, there are very few reports of adverse reactions to mRNA vaccines for the new coronavirus (SARS-CoV-2) in Japanese people. Therefore, adverse reactions in 576 vaccinated medical staff at the author's hospital were investigated.

METHODS

The subjects were 576 medical staff who wished to receive the new coronavirus (SARS-CoV-2) vaccine. The first vaccination was performed with Pfizer's new coronavirus mRNA vaccine (commercial name: Comirnaty intramuscular injection) from March 8 to March 15, 2021. The second vaccination was performed from March 29 to April 5, 2021, at an interval of more than 21 days from the first vaccination.

RESULTS

Adverse reactions were seen in six subjects in the first vaccination. There was dyspnea in one subject, arthralgia in one subject, fever/malaise in three subjects, and left axillary pain and lymphadenopathy in one subject. One subject had a reaction at the vaccination site that needed to be addressed. At the second vaccination, adverse reactions were observed in 64 subjects. There was fever in 58 subjects, malaise in 21 subjects, arthralgia in 12 subjects, aching pain in 11 subjects, headache in six subjects, chills in six subjects, nausea in three subjects, redness in two subjects, dizziness in two subjects, hives in two subjects, swelling in two subjects, cough in one subject, and itching in one subject (some had multiple adverse reactions). Fever was observed in the range of body temperature from 37.4 to 38.9 degrees.

CONCLUSIONS

Most of the adverse reactions to the COVID-19 vaccine were mild, and no serious anaphylaxis was observed. Vaccination was considered perfectly feasible if attention is paid to adverse reactions.

Addition of Baricitinib to COVID-19 Treatment Does Not Increase Bacterial Infection Compared to Standard Therapy: A Single-center Retrospective Study

Objective The coronavirus disease 2019 (COVID-19) pandemic continues to spread across the world, and the utility of many drugs for treatment has been suggested. However, few studies have examined the efficacy and safety of treatment with baricitinib, remdesivir, and dexamethasone. Methods A retrospective, cohort study of patients who were admitted to Kurashiki Central Hospital in Japan between April 6 and June 29, 2021, was conducted. Differences in patients' background characteristics, clinical outcomes, and safety were investigated in the groups with and without baricitinib treatment. The primary outcome was the bacterial infection rate, and the secondary outcome was the 28-day mortality rate. An inverse probability of treatment weighting (IPTW) analysis, including 12 covariates, was used as a propensity score analysis to reduce biases. Results In total, there were 96 patients, including 43 in the baricitinib-containing therapy (BCT) group and 53 in the non-baricitinib-containing therapy (non-BCT) group. In the BCT group, the ordinal scale on admission was 2.3% with 4, 51.1% with 5, 23.3% with 6, and 23.3% with 7. In the non-BCT group, the ordinal scale was 1.9% with 3, 18.9% with 4, 58.5% with 5, 13.2% with 6, and 7.5% with 7. After adjusting by the IPTW analysis, the BCT group did not have an increased bacterial infection rate [odds ratio (OR), 1.1; 95% confidence interval (CI), 0.36-3.38; p=0.87] or 28-day mortality rate (OR, 0.31; 95% CI, 0.07-1.3; p=0.11) compared with the non-BCT group. Conclusion BCT can be administered without increasing the infection risk compared with non-BCT.

Significant Impact of Age on Mortality and Non-significant Impact of Age on Thrombosis and Major Bleeding in Patients with COVID-19: From the CLOT-COVID Study

AIM

There is scarce data on the impact of age on clinical outcomes in patients with coronavirus disease 2019 (COVID-19).

METHOD

The CLOT-COVID Study was a retrospective, multicenter cohort study enrolling 2894 consecutive hospitalized patients with COVID-19 among 16 centers in Japan from April 2021 to September 2021. We divided the entire cohort into five groups according to age strata; -19, 20-39, 40-59, 60-79, and 80- years.

RESULTS

Most patients under 19 had mild COVID-19 on admission (99%), while older patients had more severe COVID-19. The incidence rates of clinical outcomes during hospitalization in patients aged ≤ 19, 20-39, 40-59, 60-79, and 80 ≥ years were 0.0%, 0.5%, 2.2%, 2.7%, and 1.5% for thrombosis; 0.0%, 1.2%, 1.5%, 3.4%, and 2.0% for major bleeding; and 0.0%, 0.4%, 2.0%, 12.1%, and 16.8% for all-cause death, respectively. In the stratified analysis according to COVID-19 severity on admission, the incidences of thrombosis were generally higher among patients with more severe status, although those were not significantly different among age strata in all sub-types of COVID-19 severity. However, the incidences of all-cause death were significantly higher with increasing age in all sub-types of COVID-19 severity.

CONCLUSIONS

In the current large observational study of patients with COVID-19, the risk of mortality became markedly higher with increased age. However, the risks of thrombosis and major bleeding did not necessarily increase as age increases, which seemed to be consistent irrespective of COVID-19 severity on admission.

A Convenient Risk Prediction Score for COVID-19 for Determining Whether or Not Hospitalization Is Recommended: Kanagawa Admission Priority Assessment Score

Objective Coronavirus disease 2019 (COVID-19) has caused a collapse of the medical care system, with effective triage proving vital. The Kanagawa admission priority assessment score, version-1 (KAPAS-1) and version-2 (KAPAS-2), was developed to determine the need for hospitalization. Patients with a high KAPAS (≥5) are recommended for hospitalization. We retrospectively investigated the correlation between the KAPAS and oxygen requirement during hospitalization. Methods We collected the clinical data of COVID-19 patients admitted between February 5 and December 6, 2020. Patients were divided into two groups: those who required oxygen therapy during hospitalization (OXY) and those who did not (NOXY). We assessed the correlations between the groups and KAPAS-1 and KAPAS-2. Results Overall, 117 COVID-19 patients were analyzed, including 20 OXY and 97 NOXY and 54 high KAPAS-1 and 63 high KAPAS-2. The median KAPAS-1 and KAPAS-2 were significantly higher in OXY than in NOXY (6.5 vs. 3, and 9 vs. 4, respectively). The areas under the receiver operating characteristic curves of KAPAS-1 and KAPAS-2 for oxygen requirement were 0.777 and 0.825, respectively, and the maximum values of Youden's index were 4 and 6, respectively. The proportions of high KAPAS-1 and high KAPAS-2 were significantly higher in OXY than in NOXY (90.0% vs. 37.1%, and 90.0% vs. 46.4%, respectively). Conclusion The KAPAS was significantly correlated with oxygen requirement. Furthermore, the KAPAS may be useful for deciding which patients are most likely to require hospitalization and for selecting non-hospitalized patients who should be carefully monitored.

Clinical and epidemiological features of healthcare workers after a coronavirus disease 2019 cluster infection in Japan and the effects of Kampo formulas-Hochuekkito and Kakkonto: A retrospective cohort study

It is expected that a low-toxicity natural compound like Kampo formulas would exhibit a preventive effect on COVID-19, in a global outbreak of coronavirus disease 2019 (COVID-19). Although the biological properties and safety of the representative Kampo, Hochuekkito (HET), and Kakkonto (KKT) have been confirmed in various animal model experiments and clinical studies, and in a few human studies to induce biological effects on various infectious diseases without significant toxicity, it is unclear whether HET and KKT are safe and effective for COVID-19 prevention. We summarized the clinical characteristics of HCWs and the preventive effects of HET and KKT. We performed a retrospective, single-center, cohort study that included 175 HCWs (aged 21-77 years) from a total number of 217 in a hospital with a history of COVID-19 cluster infection. In total, 175 HCWs were tested for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) antibodies. We identified 27 patients (median age: 49 ± 10.7 years) who were diagnosed with COVID-19. The patients in the group that had a body mass index ≥ 25 had a high COVID-19 infection risk, while those in the group with a Kampo formula adherence rate ≥ 40% had a low COVID-19 risk. Patients in the group with an adherence rate ≥ 40%, as well as those in the current alcohol consumption group, were at a low risk of developing severe COVID-19. In conclusion, HET and KKT may have prevented the onset or worsening of COVID-19, which could be clinically used. Obesity might have increased the patients' susceptibility to COVID-19 and the disease severity.

Timing of REGEN-COV administration and progression to severe COVID-19

Introduction

Several clinical trials have demonstrated that REGEN-COV (casirivimab and imdevimab) decreases the risk of hospitalization and death among COVID-19 patients. However, these trials did not evaluate the optimal timing of its administration, and evidence is limited regarding the relationship between the timing of administration and progression to severe COVID-19 among patients who receive REGEN-COV in a real-world setting. We examined the association between the timing of REGEN-COV administration and progression to severe COVID-19 among patients who received REGEN-COV in Japan.

Methods

We included a total of 342 COVID-19 patients (37 hospitals) who received REGEN-COV between July 19 and September 30, 2021. We calculated the difference between the date of symptom onset and the date of administration as an indicator of the timing of REGEN-COV administration and determined progression to severe COVID-19 after REGEN-COV administration. We conducted a logistic regression analysis, adjusting for potential confounders.

Results

The proportion of cases progressing to severe COVID-19 increased daily from symptom onset and sharply increased from day 5 of onset. The early administration (days 0–4) decreased the risk of progression to severity compared with late administration (after day 5), with an adjusted odds ratio of 0.29 (95% confidence interval: 0.11–0.56).

Conclusions

The early administration of REGEN-COV was associated with a decreased risk of progression to severe COVID-19 when the delta variant was dominant. The present epidemiological findings indicate that this monoclonal antibody therapy should be implemented very early in the clinical course probably even for emerging variants such as omicron BA.2.

Analysis of thyroid function in Japanese patients with coronavirus disease 2019

Thyroid dysfunction that is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is becoming increasingly recognized. However, only a few reports in Japan have addressed this issue to date. In this study, we sought to clarify whether infection with SARS-CoV-2 affected thyroid hormone levels and whether these hormones could be better predictors of prognosis in patients with coronavirus disease 2019 (COVID-19). Accordingly, we retrospectively examined 147 cases wherein thyroid hormones were measured at the time of admission among 848 Japanese patients with COVID-19 admitted to the Hyogo Prefectural Kakogawa Medical Center. All patients underwent thyroid function testing upon hospital admission. More than half (59.1%) of the patients were euthyroid. Twenty-four percent of patients had serum thyroid-stimulating hormone (TSH) levels lower than the reference range with normal serum free thyroxine (fT4) levels, and 3.4% of the patients had low TSH with high fT4 levels. Over 70% of the patients with moderate and severe COVID-19 had low serum free triiodothyronine (fT3) levels. Serum TSH and fT3 levels were inversely correlated with disease severity. The mortality rate in patients with low serum fT3 levels was significantly higher than that in those with normal serum fT3 levels.

Predictors of silent hypoxia in hospitalized patients with COVID-19 in Japan

INTRODUCTION

Silent hypoxia (SH) is common in patients with coronavirus disease (COVID-19) in Japan and other countries. Early identification of SH is important as more treatment options for COVID-19 have become available. This study aimed to identify predictors of SH using a nationwide COVID-19 registry of hospitalized patients.

METHODS

Adult patients who were admitted to hospital with COVID-19 between January 2020 and June 2021 and who were hypoxic on admission (SpO₂: 70-93%), not transferred from another facility, and who did not have disturbance of consciousness, confusion, or dementia, were included. SH was defined as hypoxia in the absence of shortness of breath/dyspnea upon admission. Predictors of SH were identified using univariable and multivariable logistic regression.

RESULTS

The study included 1904 patients, of whom 990 (52%) satisfied the criteria for SH. Compared to patients without SH, patients with SH were older, more likely to be female, and had a slightly higher SpO₂ on admission. Compared to patients without SH, patients with SH had a lower prevalence of chronic lung disease (CLD) other than chronic obstructive pulmonary disease (COPD), asthma, and obesity. Multivariable analysis revealed that the independent predictors of SH were older age, a shorter interval from symptom onset to admission, higher SpO₂, and an absence of CLD or COPD.

CONCLUSIONS

The absence of underlying lung disease and older age were important predictors of SH. The results of this study, which is the largest such study reported to date in Japan, may help clarify the mechanism of SH.

Risk factors associated with hospitalization in patients with asymptomatic or mild COVID-19 in public accommodation facilities in Tokyo

Introduction

In Japan, patients with coronavirus disease 2019 (COVID-19) who do not require medical intervention are provided care in recovery accommodation facilities (RAFs). However, some patients may require hospitalization if their symptoms become more severe during their stay. We conducted an observational study using epidemiological data of patients with COVID-19 admitted to RAFs in Tokyo.

Methods

This was an observational cohort study using data from COVID-19 patients admitted to one of the RAFs in Tokyo from December 2020 to November 2021. Admissions to the facilities were limited to patients with asymptomatic or mild COVID-19 with no underlying disease or at least stable underlying disease at the time of admission. Patients were hospitalized when they required oxygen administration or when they had, or persistent fever, or severe respiratory symptoms. We evaluated the association between hospitalization and the risk factors for hospitalization using a Cox regression model.

Results

The number of patients with COVID-19 admitted to the RAF was 6176. The number of hospitalized patients was 393 (6.4%), and the median length of stay was 5.50 days (IQR: 4.50, 6.50). In the Cox regression analysis, the hazard ratio increased with age and was significantly higher among patients aged >60 years (HR = 10.23, 95% CI: 6.72–15.57) than those in other age groups. This trend is similar to that observed in the sensitivity analysis.

Conclusion

Patients with diabetes, the elderly, obesity, and medications for gout and psychiatric diseases may be at a high risk of hospitalization. In particular, an age over 60 years was strongly associated with hospitalization.

Comparison of the Characteristics and Outcomes of COVID-19 Patients Treated by a Hospital-at-Home Service in Japan during the Alpha and Delta Waves

Coronavirus infections occurred in repeated waves caused by different variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with the number of patients increasing during each wave. A private after-hours house-call (AHHC) service provides hospital-at-home (HaH) services to patients in Japan requiring oxygen when hospital beds are in short supply. This retrospective study aimed to compare the characteristics of COVID-19 patients treated by the AHHC service during the COVID-19 waves caused by the Alpha (March−June 2021) and Delta (July−December 2021) SARS-CoV-2 variants. All patients with COVID-19 treated by the AHHC service from March to December 2021 while awaiting hospitalization were included. The data were collected from medical records and follow-up telephone interviews. The AHHC service treated 55 and 273 COVID-19 patients during the Alpha and Delta waves, respectively. The patients treated during the Delta wave were significantly younger than those treated during the Alpha wave (median: 63 years and 47 years, respectively; p < 0.001). Disease severity did not differ significantly between the two waves, but the crude case-fatality rate was significantly higher during the Alpha wave (10/55, 18.2%) than during the Delta wave (4/273, 1.4%; p < 0.001). The patient characteristics and outcomes differed between the Alpha and Delta waves.

Sex Differences in Clinical Outcomes Among Patients With COVID-19 and Cardiovascular Disease ― Insights From the CLAVIS-COVID Registry ―

Background: Male sex is associated with a worse clinical course and outcomes of COVID-19, particularly in older patients. However, studies on COVID-19 patients with cardiovascular disease and/or risk factors (CVDRF), which are representative risk factors of COVID-19, are limited. In this study, we investigated the effect of sex on the outcomes of hospitalized COVID-19 patients with CVDRF.

Methods and Results: We analyzed 693 COVID-19 patients with CVDRF. Patients were divided into 2 groups based on sex, and baseline characteristics and in-hospital outcomes were compared between the 2 groups. The mean age of the 693 patients was 68 years; 64.8% were men and 96.1% were Japanese. In a univariate analysis model, sex was not significantly associated with in-hospital mortality (odds ratio [OR] 1.22; 95% confidence interval [CI] 0.74–2.02; P=0.43). However, men had higher in-hospital mortality than women, especially among older (age ≥80 years) patients (OR 2.21; 95% CI 1.11–4.41; P=0.024). After adjusting for age and pivotal risk factors (hypertension, diabetes, heart failure, coronary artery disease, chronic lung disease, and chronic kidney disease), multivariate analysis suggested that male sex was an independent predictor of in-hospital mortality (OR 2.20; 95% CI 1.23–3.92; P=0.008).

Conclusions: In this post hoc analysis of a nationwide registry focusing on patients with COVID-19 and CVDRF, men had higher in-hospital mortality than women, especially among older patients.

Glycated hemoglobin level on admission associated with progression to severe disease in hospitalized patients with non-severe coronavirus disease 2019

Aims/Introduction

Poor glycemic control is known to be associated with severe infection development. This retrospective observational study examined whether glycemic control before coronavirus disease 2019 (COVID‐19) onset contributes to progression from non‐severe to severe COVID‐19.

Materials and Methods

Glycated hemoglobin (HbA1c) was measured on hospital admission in 415 patients with non‐severe COVID‐19. The outcome was determined from time of hospital admission to severe progression, based on clinical practice guidelines for COVID‐19 in Japan.

Results

The median value for HbA1c on admission was 6.1%, with diabetes present in 138 patients (33.3%). Among the total cohort, 93 (22.4%) progressed to severe COVID‐19 with a median (interquartile range) time of 4 days (3–7 days), whereas 322 (77.6%) were discharged after 13 days (10–17 days). A multivariable Cox proportional hazards regression model showed that HbA1c level on admission was independently associated with progression to severe COVID‐19 (hazard ratio for 1% increase 1.237, 95% confidence interval 1.037–1.475; P = 0.018), with findings consistent among several sensitivity analyses. In subgroup analyses, such an association was significant in patients with diabetes, as well as older age, current smoking habit, lower estimated glomerular filtration rate, higher C‐reactive protein level, moderate II COVID‐19, dyslipidemia and chronic respiratory disease, with no remarkable inconsistency among the subgroups. Finally, higher HbA1c level (≥7%) was more strongly associated with severe COVID‐19 progression than diabetes.

Conclusions

The results suggest that poor glycemic control before COVID‐19 onset contributes to progression from non‐severe to severe COVID‐19, even in patients with severe COVID‐19 risk factors regardless of the presence of diabetes.

Cutaneous manifestations of coronavirus disease 2019 patients in Japan

Some patients with coronavirus disease 2019 (COVID‐19) develop skin manifestations. There may be regional and racial differences in the frequency and type of COVID‐19‐associated skin manifestations. There are, however, few reports on skin manifestations in COVID‐19 patients in Asia, including Japan. We retrospectively investigated the frequency, type, and clinical course of skin manifestations in Japanese patients with COVID‐19. From 22 February 2020 to 16 August 2021, 738 Japanese patients (median age 59 years, 55% male) with laboratory‐confirmed COVID‐19 on polymerase chain reaction or antigen tests were admitted to our hospital. We mainly admitted patients with mild to moderate severity who had symptoms such as cough, fever, and oxygen demand but did not require mechanical ventilation. A total of 2.8% (21/738) of the COVID‐19 patients treated at our hospital were diagnosed with viral eruptions caused by COVID‐19. Of the 21 patients, 19 developed erythematous papules, and two developed urticaria. There were no cases of pernio‐like lesions, known as COVID toes. The median duration from the onset of other COVID‐19 symptoms to the development of skin manifestations was 9 days. This study revealed that approximately 2–3% of Japanese patients with COVID‐19 developed COVID‐19‐associated viral eruptions, most of which were erythematous papules.

Use of combined treatment of 3rd-generation cephalosporin, azithromycin and antiviral agents on moderate SARs-CoV-2 patients in South Korea: A retrospective cohort study

OBJECTIVES

To assess efficacy and safety of the combined treatment of antibiotics (3rd-generation cephalosporin and azithromycin) and antiviral agents (lopinavir/ritonavir or hydroxychloroquine) on moderate COVID-19 patients in South Korea.

METHODS

A retrospective cohort study of the 358 laboratory-confirmed SARS-CoV-2 (COVID-19) patients was conducted. 299 patients met inclusion criteria for analysis. Propensity score matching (PSM) and Cox regression method were used to control and adjust for confounding factors. Mild to moderate COVID-19 patients were managed with either CA/LoP (cephalosporin, azithromycin, and lopinavir/ritonavir) (n = 57), CA/HQ (cephalosporin, azithromycin, and hydroxychloroquine) (n = 25) or standard supportive care (n = 217). We analyzed the association between treatment group and standard supportive group in terms of three endpoints: time to symptom resolution, time to viral clearance, and hospital stay duration. Using propensity-score matching analysis, three rounds of propensity-matching analysis were performed to balance baseline characteristics among three cohorts.

RESULTS

Kaplan-Meier curves fitted using propensity score-matched data revealed no significant differences on time to symptom resolution, time to viral clearance, hospital stay duration among the three treatment arms (CA/LoP vs Standard, log-rank p-value = 0.2, 0.58, and 0.74 respectively for the three endpoints) (CA/HQ vs Standard, log-rank p-value = 0.46, 0.99, and 0.75 respectively). Similarly, Cox regression analysis on matched cohorts of CA/LoP and standard supportive group showed that hazard ratios of time to symptom resolution (HR: 1.447 [95%-CI: 0.813-2.577]), time to viral clearance(HR: 0.861, [95%-CI: 0.485-1.527]), and hospital stay duration (HR: 0.902, [95%-CI: 0.510-1.595]) were not significant. For CA/HQ and standard supportive group, hazard ratios of the three endpoints all showed no statistical significance (HR: 1.331 [95%-CI:0.631-2.809], 1.005 [95%-CI:0.480-2.105], and 0.887, [95%-CI:0.422-1.862] respectively). No severe adverse event or death was observed in all groups.

CONCLUSIONS

Combined treatment of 3rd cephalosporin, azithromycin and either low-dose lopinavir/ritonavir or hydroxychloroquine was not associated with better clinical outcomes in terms of time to symptom resolution, time to viral clearance, and hospital stay duration compared to standard supportive treatment alone. Microbiological evidence should be closely monitored when treating SARS-CoV-2 patients with antibiotics to prevent indiscreet administration of empirical antimicrobial treatments.

Effectiveness of Systemic Corticosteroids Therapy for Nonsevere Patients With COVID-19: A Multicenter, Retrospective, Longitudinal Cohort Study

OBJECTIVES

Corticosteroids were clinically used in the treatment of nonsevere patients with COVID-19, but the efficacy of such treatment lacked sufficient clinical evidence, and the impact of dose had never been studied. This study aimed to evaluate the effect of systemic corticosteroid use (SCU) in nonsevere patients with COVID-19.

METHODS

We conducted a multicenter retrospective cohort study in Hubei Province. A total of 1726 patients admitted with nonsevere type COVID-19 were included. Mixed-effect Cox model, mixed-effect Cox model with time-varying exposure, multiple linear regression, and propensity score analysis (inverse probability of treatment weight and propensity score matching) were used to explore the association between SCU and progression into severe type, all-cause mortality, and length of stay.

RESULTS

During the follow-up of 30 days, 29.8% of nonsevere patients with COVID-19 received treatment with systemic corticosteroids. The use of systemic corticosteroids was associated with higher probability of developing severe type (adjusted hazard ratio 1.81; 95% confidence interval 1.47-2.21), all-cause mortality (adjusted hazard ratio 2.92; 95% confidence interval 1.39-6.15) in time-varying Cox analysis, and prolonged hospitalization (β 4.14; P < .001) in multiple linear regression. Analysis with 2 propensity score cohorts displayed similar results. Besides, increased corticosteroid dose was significantly associated with elevated probability of developing severe type (P < .001) and prolonged hospitalization (P < .001).

CONCLUSIONS

Corticosteroid treatment against nonsevere patients with COVID-19 was significantly associated with worse clinical outcomes. The higher dose was significantly associated with elevated risk of poor disease progression. We recommend that SCU should be avoided unless necessary among nonsevere patients with COVID-19.

Clinical characteristics of the first three waves of hospitalised patients with COVID-19 in Japan prior to the widespread use of vaccination: a nationwide observational study

Background

Before widespread coronavirus disease (COVID-19) vaccinations, Japan experienced three COVID-19 epidemic waves. This study aimed to evaluate the characteristics of hospitalised COVID-19 patients and reveal temporal changes.

Methods

This study included 33,554 hospitalised patients with COVID-19 from 553 healthcare facilities. Data were analysed by age group and epidemic wave (first wave, 01/01/2020-05/31/2020; second wave, 06/01/2020-10/31/2020; and third wave, 11/01/2020-03/31/2021).

Findings

By age group, 3% (under 18), 22% (young), 34% (middle-aged), and 41% (older patients) were aged 0-17, 18-39, 40-64, and >65 years; while 16%, 35%, and 49% were in the first, second, and third wave, respectively. The patients' overall median age (58 years; interquartile range, 39-74) was lowest and highest during the second and third waves, respectively. The frequency of any comorbidity was lowest and highest during the second (44·5%) and third (63·6%) waves, respectively. The symptoms at admission and exposure history differed considerably with age. The overall case fatality rate (5%) was highest among older patients (11·4%). Case fatality rate was highest and lowest during the first (7·3%) and second (2·8%) waves, respectively. Medication use changed over time.

Interpretation

Although the overall case fatality rate remained relatively low, it was more than twice as high among older patients. After adjusting for age and comorbidities, the risk of death was highest in the first wave.

Funding

This work was supported by the Ministry of Health, Labour and Welfare "Research on Emerging and Re-emerging Infectious Diseases and Immunization" 19HA1003].

Cardiovascular considerations during the COVID-19 pandemic: A focused review for practice in Japan

The COVID-19 pandemic is continuing to have drastic consequences for patients, healthcare workers, and the health system. Its cardiovascular implications have been well described in previous studies, but original reports from Japan are sparse. Validating overseas findings in the Japanese clinical settings is crucial to improve local COVID-19 care and to clarify the pandemic's impacts in the country. This review of available literature demonstrates that in Japanese patients and clinical settings too, there is a close relationship between COVID-19 and the cardiovascular system including cardiovascular complications. On the contrary, secondary effects on cardiovascular practice including service disruptions, telemedicine, and epidemiological changes in Japan have been relatively small.

Comparative Efficacy of Tocilizumab and Baricitinib Administration in COVID-19 Treatment: A Retrospective Cohort Study

Background and Objectives: Tocilizumab and baricitinib have been observed to improve the outcomes of patients with coronavirus disease 2019 (COVID-19). However, a comparative evaluation of these drugs has not been performed. Materials and Methods: A retrospective, single-center study was conducted using the data of COVID-19 patients admitted to Hokkaido University hospital between April 2020 and September 2021, who were treated with tocilizumab or baricitinib. The clinical characteristics of the patients who received tocilizumab were compared to those of patients who received baricitinib. Univariate and multivariate logistic regression analyses of the outcomes of all-cause mortality and improvement in respiratory status were performed. The development of secondary infection events was analyzed using the Kaplan–Meier method and the log-rank test. Results: Of the 459 patients hospitalized with COVID-19 during the study, 64 received tocilizumab treatment and 34 baricitinib treatment, and those 98 patients were included in the study. Most patients were treated with concomitant steroids and exhibited the same severity level at the initiation of drug treatment. When compared to each other, neither tocilizumab nor baricitinib use were associated with all-cause mortality or improvement in respiratory status within 28 days from drug administration. Conclusions: Age, chronic renal disease and early administration of TCZ or BRT from the onset of COVID-19 were independent prognostic factors for all-cause mortality, whereas anti-viral drug use and the severity of COVID-19 at baseline were associated with an improvement in respiratory status. Secondary infection-free survival rates of patients treated with tocilizumab and those treated with baricitinib did not significantly differ. The results suggest that both tocilizumab and baricitinib could be clinically equivalent agents of choice in treatment of COVID-19.

REGN-COV2 antibody cocktail in patients with SARS-CoV-2: Observational study from a single institution in Japan

Introduction

A new treatment for coronavirus disease (COVID-19), REGN-COV2, a cocktail consisting of two neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been approved for patients at a risk of developing more severe disease.

Methods

We retrospectively reviewed patients recently diagnosed with COVID-19 with risk factors for severe infection, who were treated with the REGN-COV2 antibody cocktail between July and September 2021. The REGN-COV2 antibody cocktail was administered to patients within 7 days of disease onset, with an oxygen saturation of >93%, and with at least one comorbidity. We investigated the percentage of patients with COVID-19-related hospitalization or death, the duration of symptoms after treatment, and the adverse effects of treatment.

Results

A total of 108 patients were reviewed. Of them, 64% were aged ≥50 years, 31% had obesity, 36% had hypertension, and 18% had diabetes. In addition, 49% had multiple risk factors for severe COVID-19. Overall, 12 patients (11%) needed COVID-19-related hospitalization. No adverse effects of treatment were observed.

Conclusions

This study shows that treatment with the REGN-COV2 antibody cocktail is safe and beneficial in patients at a risk of developing severe COVID-19.

Renin-angiotensin system blocker and the COVID-19 aggravation in patients with hypertension, diabetes, renal failure, Cerebro-cardiovascular disease, or pulmonary disease: Report by the COVID-19 REGISTRY JAPAN

Background

The role of angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARB) in the pandemic context of coronavirus disease 2019 (COVID-19) continues to be debated. Patients with hypertension, diabetes mellitus, chronic renal failure, cerebro-cardiovascular disease, or chronic obstructive pulmonary disease (COPD), who often use ACEi/ARB, may be at risk of severe COVID-19. However, there are no data available on the association of ACEi/ARB use with COVID-19 severity in this population.

Methods

This study is an observational study of patients with a positive severe acute respiratory syndrome coronavirus 2 test and inpatient treatment at a healthcare facility, using the registry information of COVIREGI-JP. Our primary outcomes were in-hospital death, ventilator support, extracorporeal membrane oxygenation support, and intensive care unit admission. Out of the 6055 patients, 1921 patients with preexisting hypertension, diabetes mellitus, chronic renal failure, cerebro-cardiovascular disease, or COPD were enrolled.

Results

Factors associated with an increased risk of the primary outcomes were aging, male sex, COPD, severe renal impairment, and diabetes mellitus. No correlations were observed with ACEi/ARB, cerebro-cardiovascular diseases, or hypertension. Associated factors in male patients were aging, renal impairment, hypertension, and diabetes. In female patients, factors associated with an increased risk were aging, ACEi/ARB, renal impairment, and diabetes, whereas hypertension was associated with a lower risk of the primary outcomes.

Conclusions

Independent factors for the primary outcomes were aging, male sex, COPD, severe renal impairment, and diabetes, but not ACEi/ARB. Based on this registry data analysis, more detailed data collection and analysis is needed with the cooperation of multiple healthcare facilities.

Serum IL-28A/IFN-λ2 is linked to disease severity of COVID-19

Type III interferons (IFNs) play an important role in respiratory viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to determine whether the expression of serum type III IFNs predicted disease severity among patients with the coronavirus disease (COVID-19). A retrospective cohort study was conducted of patients admitted to a single hospital between March 21, 2020, and March 31, 2021. Patients were divided into mild to moderate I (MM) and moderate II to severe (MS) groups based on the COVID-19 severity classification developed by the Japanese Ministry of Health, Labor and Welfare. A total of 257 patients were included in the analysis. Human interleukin-28A (IL-28A/IFN-λ2) expression was significantly lower, and interleukin (IL)-6 expression was significantly higher in the MS group than in the MM group (both p < 0.001). In addition, IL-28A/IFN-λ2 was statistically significantly inversely correlated with the time from disease onset to negative SARS-CoV-2 PCR results (p = 0.049). Multivariable logistic regression analysis showed that IL-28A/IFN-λ2 was an independent predictor of disease severity (p = 0.021). The low expression of IL-28A/IFN-λ2 may serve as a serum biomarker that predicts the severity of COVID-19, possibly through the mechanism of delayed viral elimination.

Association between pre-admission anticoagulation and in-hospital death, venous thromboembolism, and major bleeding among hospitalized COVID-19 patients in Japan

Purpose

The coagulation activation leads to thrombotic complications such as venous thromboembolism (VTE) in patients with coronavirus disease‐2019 (COVID‐19). Prophylactic anticoagulation therapy has been recommended for hospitalized COVID‐19 patients in clinical guidelines. This retrospective cohort study aimed to examine the association between pre‐admission anticoagulation treatment and three outcomes: in‐hospital death, VTE, and major bleeding among hospitalized COVID‐19 patients in Japan.

Methods

Using a large‐scale claims database built by the Medical Data Vision Co. in Japan, we identified patients hospitalized for COVID‐19 who had outpatient prescription data at least once within 3 months before being hospitalized. Exposure was set as pre‐admission anticoagulation treatment (direct oral anticoagulant or vitamin K antagonist), and outcomes were in‐hospital death, VTE, and major bleeding. We conducted multivariable logistic regression analyses, adjusting for a single summarized score (a propensity score of receiving pre‐admission anticoagulation) for VTE and major bleeding, due to the small number of outcomes.

Results

Among the 2612 analytic patients, 179 (6.9%) had pre‐admission anticoagulation. Crude incidence proportions were 13.4% versus 8.5% for in‐hospital death, 0.56% versus 0.58% for VTE, and 2.2% versus 1.1% for major bleeding among patients with and without pre‐admission anticoagulation, respectively. Adjusted odds ratios (95% confidence intervals) were 1.25 (0.75–2.08) for in‐hospital death, 0.21 (0.02–1.97) for VTE, and 2.63 (0.80–8.65) for major bleeding. Several sensitivity analyses did not change the results.

Conclusions

We found no evidence that pre‐admission anticoagulation treatment was associated with in‐hospital death. However, a larger sample size may be needed to conclude its effect on VTE and major bleeding.

Effectiveness of Favipiravir on Nonsevere, Early-Stage COVID-19 in Japan: A Large Observational Study Using the COVID-19 Registry Japan

Introduction

Several randomized controlled trials have compared the effectiveness of favipiravir with that of placebo. However, evidence regarding its effect on nonsevere, early-stage coronavirus disease 2019 (COVID-19) remains insufficient.

Methods

We used the COVID-19 Registry Japan, a nationwide registry of inpatients with COVID-19, for evaluating the effectiveness of favipiravir on patients with nonsevere, early-stage COVID-19. Eligible patients, who did not need supplementary oxygen therapy at admission, were classified according to two regimens (starting favipiravir therapy within 4 days from admission vs. no favipiravir during hospitalization) and were then compared using a three-step method (cloning, censoring, and weighting). The primary outcome was supplementary oxygen requirement during hospitalization, and the secondary outcomes were the need for invasive mechanical ventilation or extracorporeal membrane oxygenation (IMV/ECMO) and overall mortality at 30 days.

Results

A total of 7654 cases were analyzed. The “start favipiravir” regimen did not show substantial differences in the primary outcome [hazard ratio 0.825, 95% confidence interval (CI) 0.657–1.04, p = 0.098] and both of the secondary outcomes [need for IMV/ECMO and overall 30-day mortality, hazard ratio 1.02 (95% CI 0.649–1.60) and 0.869 (95% CI 0.519–1.46), p = 0.929 and 0.594, respectively].

Conclusions

In this large cohort from a COVID-19 registry, favipiravir was not associated with a positive effect on the clinical outcome on patients with nonsevere, early-stage COVID-19, suggesting that it is not an essential drug for COVID-19 treatment.

Clinical Significance of COVID-19 and Diabetes: In the Pandemic Situation of SARS-CoV-2 Variants including Omicron (B.1.1.529)

Simple Summary

Amidst the dual pandemics of diabetes and coronavirus disease 2019 (COVID-19), with the constant emergence of novel variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a vicious cycle has been created, i.e., a hyperglycemic state contributes to the severe clinical course of COVID-19, which in turn has deleterious effects on glycometabolism and in some cases causes new-onset diabetes. Here, we present a comprehensive review of the current literature on the clinical and experimental findings associated with the interrelationship between diabetes and COVID-19. To control disease outcomes and glucometabolic complications in COVID-19, this issue is still being investigated.

Abstract

The coronavirus disease 2019 (COVID-19) global pandemic, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains uncontrolled, with the spread of emerging variants. According to accumulating evidence, diabetes is one of the leading risk factors for a severe COVID-19 clinical course, depending on the glycemic state before admission and during COVID-19 hospitalization. Multiple factors are thought to be responsible, including an altered immune response, coexisting comorbidity, and disruption of the renin-angiotensin system through the virus–host interaction. However, the precise underlying mechanisms remain under investigation. Alternatively, the focus is currently on the diabetogenic and ketosis-prone potential of SARS-CoV-2 itself, even for probable triggers of stress and steroid-induced hyperglycemia in COVID-19. In this article, we present a comprehensive review of the recent literature on the clinical and experimental findings associated with diabetes and COVID-19, and we discuss their bidirectional relationship, i.e., the risk for an adverse prognosis and the deleterious effects on glycometabolism. Accurate assessments of the incidence of new-onset diabetes induced by COVID-19 and its pathogenicity are still unknown, especially in the context of the circulation of SARS-CoV-2 variants, such as Omicron (B.1.1.529), which is a major challenge for the future.

Risk factors associated with hospital transfer among mild or asymptomatic COVID-19 patients in isolation facilities in Tokyo: a case-control study

•

Facility-based isolation for COVID-19 in Tokyo involved remote health observation.

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This study was conducted in a prehospital setting using multivariable analysis.

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Older age, male sex, and higher BMI were associated with transfers to hospital.

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Comorbidities, such as bronchial asthma, increased the risk for hospital transfer.

•

Some patients requiring urgent oxygenation showed few signs of dyspnea (silent hypoxia).

Objectives

The Tokyo Metropolitan Government has been implementing facility-based isolation of asymptomatic/mild coronavirus disease (COVID-19) patients to facilitate timely hospital referral. However, there are only a few published studies in prehospital settings, and the factors associated with hospital transfer are unclear. Our study identified the factors associated with COVID-19 deterioration in a prehospital setting.

Methods

This case-control study assessed the risk factors for hospital transfer from isolation facilities and the need for ambulance transport due to deterioration among COVID-19 patients, using multivariate logistic regression analysis.

Results

In total, 10 590 patients (median age 34 years), with male predominance (61.1%), were included. 367 (3.5%) were transferred to hospital, of whom 44 (12.0%) required ambulance transport. Hypertension, diabetes, and bronchial asthma were prevalent in 704 (6.6%), 195 (1.8%), and 305 (2.9%) patients, respectively. After adjustment, older age, male sex, higher body mass index (BMI), and comorbidities (including diabetes, inflammatory bowel disease, and bronchial asthma) were associated with hospital transfer. Older age, male sex, and higher BMI significantly increased the risk of transfer by ambulance.

Conclusions

Our results may be beneficial for the development of intervention measures for probable future COVID-19 waves.

Elevated Plasma Soluble C-Type Lectin-like Receptor 2 Is Associated with the Worsening of Coronavirus Disease 2019

Although thrombosis in coronavirus disease 2019 (COVID-19) infection has attracted attention, the mechanism underlying its development remains unclear. The relationship between platelet activation and the severity of COVID-19 infection was compared with that involving other infections. Plasma soluble C-type lectin-like receptor 2 (sCLEC-2) levels were measured in 46 patients with COVID-19 infection and in 127 patients with other infections. The plasma sCLEC-2 levels in patients with COVID-19 infection {median (25th, 75th percentile), 489 (355, 668) ng/L} were significantly higher (p < 0.001) in comparison to patients suffering from other pneumonia {276 (183, 459) ng/L}, and the plasma sCLEC-2 levels of COVID-19 patients with severe {641 (406, 781) ng/L} or critical illness {776 (627, 860) ng/L} were significantly higher (p < 0.01, respectively) in comparison to those with mild illness {375 (278, 484) ng/L}. The ratio of the sCLEC-2 levels to platelets in COVID-19 patients with critical illness of infection was significantly higher (p < 0.01, p < 0.001 and p < 0.05, respectively) in comparison to COVID-19 patients with mild, moderate or severe illness. Plasma sCLEC-2 levels were significantly higher in patients with COVID-19 infection than in those with other infections, suggesting that platelet activation is triggered and facilitated by COVID-19 infection.

The role of after-hours house-call medical service in the treatment of COVID-19 patients awaiting hospital admission: A retrospective cohort study

Due to the increasing number of coronavirus disease 2019 (COVID-19) cases in Japan, hospitals are unable to provide admission and immediate inpatient care. The after-hours house call (AHHC) service offers telephone consultations and in-home care to patients awaiting admission. Currently, there is no report on the management of COVID-19 patients when inpatient beds are insufficient.We aimed to describe the clinical characteristics and outcomes of COVID-19 patients treated by an AHHC medical service in Osaka and Tokyo, between April and May 2021 (during the fourth wave in Japan). Patients were classified into 2 groups: Moderate I and Moderate II, according to the severity of infection under Japanese guidelines. A retrospective study of the hospital records and follow-up telephone consultations was performed.The AHHC treated a total of 55 COVID-19 patients (17 with Moderate I, 38 with Moderate II disease). The median ages (interquartile range) were 63 (49-80.5) and 64 (50.8-81), respectively. In each group, approximately 30% of AHHC patients received out-of-hospital oxygen therapy for the duration of their treatment until it was no longer required. Major symptoms, including shortness of breath or difficulty breathing (47.1% and 78.9%, respectively) and fever or chills (41.2% and 76.3%, respectively) were lower in the Moderate I group than in the Moderate II group. Overall, 16.4% of patients died, with 17.6% in the Moderate I group and 15.8% in the Moderate II group.We found the proportion of mortality in patients treated by the AHHC was slightly higher to that of patients treated in Japanese hospitals. This study will provide an alternative management of patients requiring oxygen in situations where hospital beds are in short supply.

Immune interventions in COVID-19: a matter of time?

As the COVID-19 pandemic is still ongoing, and considering the lack of efficacy of antiviral strategies to this date, and the reactive hyperinflammation leading to tissue lesions and pneumonia, effective treatments targeting the dysregulated immune response are more than ever required. Immunomodulatory and immunosuppressive drugs have been repurposed in severe COVID-19 with contrasting results. The heterogeneity in the timing of treatments administrations could be accountable for these discrepancies. Indeed, many studies included patients at different timepoints of infection, potentially hiding the beneficial effects of a time-adapted intervention. We aim to review the available data on the kinetics of the immune response in beta-coronaviruses infections, from animal models and longitudinal human studies, and propose a four-step model of severe COVID-19 timeline. Then, we discuss the results of the clinical trials of immune interventions with regards to the timing of administration, and finally suggest a time frame in order to delineate the best timepoint for each treatment.

Intensive care burden of COVID-19 in tertiary care hospitals during the first year of outbreak in Kawasaki City, Japan: A retrospective cohort study

Introduction

This study aimed to describe the changes in the intensive care burden of coronavirus disease 2019 (COVID-19) during the first year of outbreak in Japan.

Methods

This retrospective cohort study included COVID-19 patients who received mechanical ventilation (MV) support in two designated hospitals for critical patients in Kawasaki City. We compared the lengths of MV and stay in the intensive care unit (ICU) or high care unit (HCU) according to the three epidemic waves. We calculated in-hospital mortality rates in patients with or without MV.

Results

The median age of the sample was 65.0 years, and 22.7% were women. There were 37, 29, and 62 patients in the first (W1), second (W2), and third waves (W3), respectively. Systemic steroids, remdesivir, and prone positioning were more frequent in W2 and W3. The median length of MV decreased from 18.0 days in W1 to 13.0 days in W3 (P = 0.019), and that of ICU/HCU stay decreased from 22.0 days in W1 to 15.5 days in W3 (P = 0.027). The peak daily number of patients receiving MV support was higher at 18 patients in W1, compared to 8 and 15 patients in W2 and W3, respectively. The mortality rate was 23.4%, which did not significantly change (P = 0.467).

Conclusions

The lengths of MV and ICU/HCU stay per patient decreased over time. Despite an increase in the number of COVID-19 patients who received MV in W3, this study may indicate that the intensive care burden during the study period did not substantially increase.

Clinical characteristics and outcomes of COVID-19 in pregnant women: a propensity score matched analysis of the data from the COVID-19 Registry Japan

Background

Several studies have investigated whether pregnancy is a risk factor for developing severe COVID-19; however, the results remain controversial. In addition, the information regarding risk factors for developing severe COVID-19 in pregnant women is limited.

Methods

A retrospective cohort study analyzing the data from the nationwide COVID-19 registry in Japan was conducted. Propensity score matched analysis was performed to compare COVID-19 severity between pregnant and nonpregnant women. Multivariate analysis was also conducted to evaluate risk factors for developing moderate-to-severe COVID-19 in pregnant women.

Results

During the study period, 254 pregnant and 3752 nonpregnant women of reproductive age were identified. After propensity score matching, 187 pregnant women and 935 nonpregnant women were selected. A composite outcome of moderate-to-severe COVID-19 was more frequently observed in pregnant women than that of nonpregnant women (n=18, 9.6% vs. n=46, 4.9%; P=0.0155). In multivariate analysis, the presence of underlying diseases and being in the second-to-third trimester of pregnancy were recognized as risk factors for moderate-to-severe COVID-19 in pregnant women (odds ratio [95% confidence interval]: 5.295 [1.21-23.069] and 3.871 [1.201-12.477], respectively).

Conclusions

Pregnancy could be a risk factor for moderate-to-severe COVID-19 for women in Japan. In addition to the presence of comorbidities, advanced pregnancy stages may contribute to greater risks for developing moderate-to-severe COVID-19 in pregnant women.

Comparison of patient characteristics and in-hospital mortality between patients with COVID-19 in 2020 and those with influenza in 2017-2020: a multicenter, retrospective cohort study in Japan

Background

COVID-19 has worse mortality than influenza in American and European studies, but evidence from the Western Pacific region is scarce.

Methods

Using a large-scale multicenter inpatient claims data in Japan, we identified individuals hospitalised with COVID-19 in 2020 or influenza in 2017–2020. We compared patient characteristics, supportive care, and in-hospital mortality, with multivariable logistic regression analyses for in-hospital mortality overall, by age group, and among patients with mechanical ventilation.

Findings

We identified 16,790 COVID-19 patients and 27,870 influenza patients, with the different age distribution (peak at 70–89 years in COVID-19 vs. bimodal peaks at 0–9 and 80–89 years in influenza). On admission, the use of mechanical ventilation was similar in both groups (1·4% vs. 1·4%) but higher in the COVID-19 group (3·3% vs. 2·5%; p<0·0001) during the entire hospitalisation. The crude in-hospital mortality was 5·1% (856/16,790) for COVID-19 and 2·8% (791/27,870) for influenza. Adjusted for potential confounders, the in-hospital mortality was higher for COVID-19 than for influenza (adjusted odds ratio [aOR] 1·83, 95% confidence interval [CI] 1·64–2·04). In age-stratified analyses, the aOR (95%CI) were 0·78 (0·56–1·08) and 2·05 (1·83–2·30) in patients aged 20–69 years and ≥70 years, respectively (p-for-interaction<0·0001). Among patients with mechanical ventilation, the aOR was 0·79 (0·59–1·05).

Interpretation

Patients hospitalised with COVID-19 in Japan were more likely to die than those with influenza. However, this was mainly driven by findings in older people, and there was no difference once mechanical ventilation was started.

Funding

Ministry of Health, Labour and Welfare of Japan (21AA2007).

The Association Between FT3 With the Outcome and Inflammation/Coagulopathy/Fibrinolysis of COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has caused substantial threats to people's physical health and lives, claiming the lives of over 5 million people worldwide. It is imperative to identify the disease severity and intervene with effective therapy as early as possible. Previous studies have shown that low free triiodothyronine (FT3) may possess the predictive value on COVID-19 prognosis.

METHODS

In this retrospective cohort study, 15-day clinical and laboratory data of 186 hospitalized patients of COVID-19 after admission were analyzed. Groups were based on the disease severity of COVID-19, survival or non-survival, and presence or absence of euthyroid sick syndrome (ESS). Categorical variables were compared with the chi-square test or Fisher's exact test. Continuous variables were tested by Wilcoxon rank-sum test for the non-normal distribution. Spearman correlations were used to assess the correlations between FT3 with clinic parameters of multiple time points.

RESULTS

The non-survival patients had significant lower levels of FT3 (3.24 ± 0.42 vs. 4.19 ± 0.08 pmol/L, p < 0.05) and thyroid-stimulating hormone (TSH) (0.69 ± 0.19 vs. 2.32 ± 0.2 uIU/ml, p < 0.05), and the FT3 of severe patients was significantly lower than that of non-severe patients (3.67 ± 0.14 vs. 4.33 ± 0.09 pmol/L, p < 0.05). Fifty-nine cases of COVID-19 patients were diagnosed with ESS. Compared with non-ESS patients, those with ESS were older and had higher proportions of fever, shortness of breath, hypertension, diabetes, severe disease, and mortality. In addition, the correlation analysis between FT3 and clinical parameters showed that FT3 were positively related to the lymphocyte count and albumin and negatively correlated with C-reactive protein, erythrocyte sedimentation rate, and D-dimer at all time points in the first 15 days after admission.

CONCLUSION

Low FT3 had a significant predictive value on the prognosis of COVID-19 patients, and FT3 was significantly related with clinic parameters of inflammation/coagulopathy/fibrinolysis.

Association between Nafamostat Mesylate and In-Hospital Mortality in Patients with Coronavirus Disease 2019: A Multicenter Observational Study

Nafamostat mesylate may be effective against coronavirus disease 2019 (COVID-19). However, it is not known whether its use is associated with reduced in-hospital mortality in clinical practice. We conducted a retrospective observational study to evaluate the effect of nafamostat mesylate in patients with COVID-19 using the Medical Data Vision Co. Ltd. hospital-based database in Japan. We compared patients with COVID-19 who were (n = 121) and were not (n = 15,738) administered nafamostat mesylate within 2 days of admission between January and December 2020. We conducted a 1:4 propensity score matching with multiple imputations for smoking status and body mass index and combined the 20 imputed propensity score-matched datasets to obtain the adjusted odds ratio for in-hospital mortality. Crude in-hospital mortality was 13.2% (16/121) and 5.0% (790/15,738), respectively. In the propensity score-matched analysis with multiple imputations, the adjusted odds ratio (use vs. no use of nafamostat mesylate) for in-hospital mortality was 1.27 (95% confidence interval: 0.61–2.64; p = 0.52). Sensitivity analyses showed similar results. The results of this retrospective observational study did not support an association between nafamostat mesylate and improved in-hospital outcomes in patients with COVID-19, although further studies with larger sample sizes are warranted to assess the generalizability of our findings.

The effect of casirivimab with imdevimab on disease progression in nonsevere COVID‐19 patients in a single hospital in Japan

Background

Recent randomized trials have revealed that neutralizing monoclonal antibodies can reduce disease progression in mild–moderate COVID‐19 patients. However, no studies have investigated the effect of neutralizing monoclonal antibodies on clinical outcomes in Japan.

Methods

A single‐center retrospective and prospective cohort study was conducted. All consecutive febrile nonsevere COVID‐19 patients with at least one risk factor were included. The primary outcome was progression to severe COVID‐19. Severe COVID‐19 cases were defined as patients requiring oxygen therapy and dexamethasone. The differences in the primary outcomes between the patients who were treated with casirivimab with imdevimab (treatment group) and those who were not (control group) were compared using the chi‐squared test.

Results

A total of 128 patients were included. Of those, the mean age was 53.6 years old (SD 9.9), and 52 (40.6%) were women. Fifty‐three patients were treated with casirivimab with imdevimab, and 75 patients were given the standard treatment only. The primary outcome occurred in eight (15.1%) of the 53 patients in the treatment group and 33 (44.0%) of the 75 patients in the control group (odd ratio [OR] 0.23, 95% CI 0.09 to 0.55). The multivariate analysis revealed that the use of casirivimab with imdevimab (OR 0.21, 95% CI 0.08 to 0.54) was the only independent risk factor associated with progression to severe COVID‐19. No patients died during hospitalization in either group.

Conclusion

Similar to other countries, casirivimab with imdevimab significantly reduced disease progression in early nonsevere COVID‐19 patients with fever and risk factors in Japan.