Do hospitals need to establish multiple hospital districts? A hospital-based perspective on the benefits of scale.

Background: During the fight against COVID-19, China's public hospitals played the main role in taking on the most urgent, dangerous and arduous medical treatment and work. Therefore, in order to promote the high-quality development of hospitals, it is necessary to support some potential public hospitals to build and develop a "One Hospital with Multiple Campuses System" (OHMC) based on controlling the size of single hospitals, and to quickly convert their functions in the event of a severe epidemic. Methods: The Cobb-Douglas production function and log-transformed production function were used to measure the appropriate hospital size for 22 public hospitals in a region of China. Results: The eight OHMC hospitals that planned to be build are basically qualified to handle the conditions and potential of multi-districts from the perspective of economy of scale. The OHMC hospitals in operation appear to have weakened incremental scale rewards, because they are in the process of development, but they are still higher than the overall level of single-campus hospitals. Conclusion: The expansion of hospital scale may bring the advantages of group development, but it may also bring about problems including rising hospital cost, increasing management and operation cost, inefficient allocation of medical resources and unbalanced development.

A constant-law model for the filtering rate of non-woven fabrics

During the global pandemic of COVID-19, the term 'N95' is frequently encountered in our daily life. 'N95' is the abbreviation of facepiece respirators that meet the class 95 standard of US National Institute for Occupational Safety and Health (NIOSH). The number '95' means that the N95 respirator can filter >95% of airborne particles. Numerically, 95% or 0.95 is very close to the function value of f(x)=1-e-x, when x=3. Intuitively, there might be some underlying relationship between f(3) and the filtering rate 0.95. In this paper, a constant-law model is presented, giving clear physical picture for the filtering rate of non-woven fabrics. The derived physical model may also be used as a standard for particulate-filtering non-woven fabric products such as facepiece respirators.

Impact of vaccination on post-acute sequelae of SARS CoV-2 infection in patients with rheumatic diseases (preprint)

Objective: Vaccination decreases the risk of severe COVID-19 but its impact on post-acute sequelae of COVID-19 (PASC) is unclear among patients with systemic autoimmune rheumatic diseases (SARDs) who may have blunted vaccine immunogenicity and be vulnerable to PASC. Methods: We prospectively enrolled SARD patients from a large healthcare system who survived acute infection to complete surveys. The symptom-free duration and the odds of PASC (any symptom lasting [≥] 28 or 90 days) were evaluated using restricted mean survival time and multivariable logistic regression, respectively, among those with and without breakthrough infection ([≥] 14 days after initial vaccine series). Results: Among 280 patients, the mean age was 53 years, 80% were female, and 82% were white. The most common SARDs were inflammatory arthritis (59%) and connective tissue disease (24%). Those with breakthrough infection had more upper respiratory symptoms, and those with non-breakthrough infection had more anosmia, dysgeusia, and joint pain. Compared to those with non-breakthrough COVID-19 infection (n=164), those with breakthrough infection (n=116) had significantly more symptom-free days over the follow-up period (+28.9 days, 95% CI: 8.83, 48.89; p=0.005) and lower odds of PASC at 28 and 90 days (aOR 0.49, 95% CI: 0.29, 0.83 and aOR 0.10, 95% CI: 0.04, 0.22, respectively). Conclusion: Vaccinated patients with SARDs were less likely to experience PASC compared to those not fully vaccinated. These findings support the benefits of vaccination for patients with SARDs and suggest that the immune response to acute infection is important in the pathogenesis of PASC in SARD patients.

Factors Associated with COVID-19 Breakthrough Infection in the Pre-Omicron Era Among Vaccinated Patients with Rheumatic Diseases: A Cohort Study (preprint)

Objective Rheumatic disease patients on certain immunomodulators are at increased risk of impaired humoral response to SARS-CoV-2 vaccines. We aimed to identify factors associated with breakthrough infection among patients with rheumatic diseases. Methods We identified patients with rheumatic diseases being treated with immunomodulators in a large healthcare system who received at least two doses of either the mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech) vaccines or one dose of the Johnson & Johnson-Janssen (J&J) vaccine. We followed patients until SARS-CoV-2 infection, death, or December 15, 2021, when the Omicron variant became dominant in our region. We estimated the association of baseline characteristics with the risk of breakthrough infection using multivariable Cox regression. Results We analyzed 11,468 patients (75% female, mean age 60 years). Compared to antimalarial monotherapy, multiple immunomodulators were associated with higher risk of infection: anti-CD20 monoclonal antibodies (aHR 5.20, 95% CI: 2.85, 9.48), CTLA-4 Ig (aHR 3.52, 95% CI: 1.90, 6.51), mycophenolate (aHR 2.31, 95% CI: 1.25, 4.27), IL-6 inhibitors (aHR 2.15, 95% CI: 1.09, 4.24), JAK inhibitors (aHR 2.02, 95% CI: 1.01, 4.06), and TNF inhibitors (aHR 1.70, 95% CI: 1.09, 2.66). mRNA-1273 recipients had a lower risk of breakthrough infection compared to BNT162b2 recipients (aHR 0.66, 95% CI: 0.50, 0.86). There was no association of sex, body mass index, smoking status, race, or ethnicity with risk of breakthrough infection. Conclusion Among patients with rheumatic diseases, multiple immunomodulators were associated with increased risk of breakthrough infection. These results highlight the need for additional mitigation strategies in this vulnerable population.

Mechanism of modified xiangsha liujunzi decoction on COVID-19 with lung and spleen Qi deficiency syndrome in recovery period based on network pharmacology and molecular docking

Objective: To explore the mechanism of modified Xiangsha Liujunzi Decoction on COVID-19 with lung and spleen Qi deficiency syndrome in recovery period.

COVID-19 Outcomes Among Users of CD20 Inhibitors for Immune-Mediated Diseases: A Comparative Cohort Study (preprint)

ObjectivePatients with immune-mediated diseases treated with CD20 inhibitors may have worse COVID-19 outcomes due to impaired humoral immunity, but differences versus the general population are unknown. MethodsWe identified patients with immune-mediated diseases who received CD20 inhibitors within one year prior to the index date of PCR-confirmed COVID-19 between January 31, 2020, and January 31, 2021. Comparators with COVID-19 were matched up to 5:1 by age, sex, and PCR date. Hazard ratios (HRs) and 95% confidence intervals (CIs) for hospitalization, mechanical ventilation, and death in CD20 inhibitor users versus comparators were estimated using Cox regression. ResultsWe identified 114 cases with COVID-19 who had received CD20 inhibitors for immune-mediated diseases (mean age 55 years, 70% female) and 559 matched comparators with COVID-19 (mean age 54 years, 70% female). CD20 inhibitor-treated cases had higher mortality (aHR 2.16; 95% CI: 1.03 to 4.54) than matched comparators. Risks of hospitalization (aHR 0.88; 95% CI: 0.62 to 1.26) and mechanical ventilation (aHR 0.82; 95% CI: 0.36 to 1.87) were similar. Similar trends were seen in analyses according to type of indication (e.g., rheumatic or neurologic disease) and duration of CD20 inhibitor use (<1 or [≥]1 year), and after excluding patients with interstitial lung disease, cancer, and those on glucocorticoids prior to COVID-19 diagnosis. ConclusionsPatients who received CD20 inhibitors for immune-mediated diseases prior to COVID-19 had higher mortality following COVID-19 than matched comparators, highlighting the urgent need to mitigate excess risks in CD20 inhibitor users during the ongoing pandemic. Key MessagesO_ST_ABSWhat is already known about this subject?C_ST_ABSO_LIPatients with immune-mediated diseases treated with CD20 inhibitors may have worse COVID-19 outcomes than those treated with other immunomodulatory medications, but differences compared to the general population are unknown. C_LI What does this study add?O_LICD20 inhibitor-treated cases had over two-fold higher risk of mortality than matched general population comparators, although risks of hospitalization and mechanical ventilation were similar. C_LI How might this impact on clinical practice or future developments?O_LIThere is an urgent need for risk mitigation strategies, such as SARS-CoV-2 monoclonal antibodies or booster vaccinations, for patients with immune-mediated diseases treated with CD20 inhibitors during the ongoing COVID-19 pandemic. C_LI

Mutation and Virulence of SARS-CoV-2 Strains Circulating in Anhui Province, China (preprint)

Background: The genome of SARS-CoV-2 has shown considerable variation during its spreading. Monitoring variations in the virus genome to understand the evolution and spread of the virus is extremely important. Methods: Seven SARS-CoV-2 strains (BB127, BB183, HB030, MAS525, HF3028, FY1494, and SZ005) circulating in Anhui Province, China were isolated and sequenced for evolutionary analysis. Five strains were further cultured in vitro and were subjected to viral growth assay, TCID50 assay, and detection of spike protein expression. Next generation sequence (NGS) analysis were applied to investigate the mutation frequencies throughout the whole genome at different time gradients in vitro. Findings: Our observations revealed that in vitro cultured SARS-CoV-2 virus had much higher mutation frequency (up to ~20 times) than that in infected patients, and the mutation in nonstructural protein 14 (nsp14) might increase the genomic mutation frequency. Different strains had various amount of spike protein which may positively correlated with the virus replication capacity but may be influenced by other viral factors. Interpretation: Our study suggested that SARS-CoV-2 has the potential to diversify under favorable conditions. Monitoring viral mutations is not only helpful for better understanding of virus evolution and virulence change, but also the key to prevent virus transmission and disease progression. SARS-CoV-2 genomic variation analysis may also provide potential ideas for more efficient vaccine development and clinical treatment. Funding: This work is funded by Special Project for Emergency Scientific and Technological Research on New Coronavirus Infection (YG, No. YD9110002001), Emergency Research Project of Novel Coronavirus Infection of Anhui Province (Grant numbers 202004a07020002; 202004a07020004), Postdoctoral Research Foundation of China (2020M670084ZX) and the Fundamental Research Funds for the Central Universities (WK9110000166; WK9110000167).Declaration of Interests: We declare no competing interests.Ethics Approval Statement: The study was conformed to the principles of the Declaration ofHelsinki and approved by the Ethics Committee of the First Affiliated Hospital of USTC..

COVID-19 severity in asthma patients: A multi-center matched cohort study (preprint)

ObjectiveThe evidence pertaining to the effects of asthma on Coronavirus disease 2019 outcomes has been unclear. To improve our understanding of the clinically important association of asthma and Coronavirus disease 2019. MethodsA matched cohort study was performed using data from the Mass General Brigham Health Care System (Boston, MA). Adult (age [≥] 18 years) patients with confirmed Coronavirus disease 2019 and without chronic obstructive pulmonary disease, cystic fibrosis, or interstitial lung disease between March 4, 2020 and July 2, 2020 were analyzed. Up to 5 non-asthma comparators were matched to each asthma patient based on age (within 5 years), sex, and date of positive test (within 7 days). The primary outcomes were hospitalization, mechanical ventilation, and death, using multivariable Cox-proportional hazards models accounting for competing risk of death, when appropriate. Patients were followed for these outcomes from diagnosis of Coronavirus disease 2019 until July 2, 2020. ResultsAmong 562 asthma patients, 199 (21%) were hospitalized, 15 (3%) received mechanical ventilation, and 7 (1%) died. Among the 2686 matched comparators, 487 (18%) were hospitalized, 107 (4%) received mechanical ventilation, and 69 (3%) died. The adjusted Hazard Ratios among asthma patients were 0.99 (95% Confidence Internal 0.80, 1.22) for hospitalization, 0.69 (95% Confidence Internal 0.36, 1.29) for mechanical ventilation, and 0.30 (95% Confidence Internal 0.11, 0.80) for death. ConclusionsIn this matched cohort study from a large Boston-based healthcare system, asthma was associated with comparable risk of hospitalization and mechanical ventilation but a lower risk of mortality.