scholarly journals Deducing the Dose-response Relation for Coronaviruses from COVID-19, SARS and MERS Meta-analysis Results

2020 ◽  
Author(s):  
Xiaole Zhang ◽  
Jing Wang
Keyword(s):  
Systematic Review ◽  
Viral Infection ◽  
Dose Response ◽  
Meta Analysis ◽  
A Priori ◽  
Exposure Dose ◽  
Infection Risk ◽  
Transmission Risk ◽  
Viral Shedding ◽  
Shed Light

AbstractThe fundamental dose-response relation is still missing for better evaluating and controlling the transmission risk of COVID-19. A recent study by Chu et al. has indicated that the anticipated probability of viral infection is about 12.8% within 1 m and about 2.6% at further distance through a systematic review and meta-analysis. This important information provides us a unique opportunity to assess the dose-response relation of the viruses, if reasonable exposure dose could be estimated. Here we developed a simple framework to integrate the a priori dose-response relation for SARS-CoV based on mice experiments, and the recent data on infection risk and viral shedding, to shed light on the dose-response relation for human. The developed dose-response relation is an exponential function with a constant k in the range of 6.19×104 to 7.28×105 virus copies. The result mean that the infection risk caused by one virus copy in viral shedding is about 1.5×10−6 to 1.6×10−5. The developed dose-response relation provides a tool to quantify the magnitude of the infection risk.

scholarly journals Dose-response Relation Deduced for Coronaviruses from COVID-19, SARS and MERS Meta-analysis Results and its Application for Infection Risk Assessment of Aerosol Transmission

2020 ◽  
Author(s):  
Xiaole Zhang ◽  
Jing Wang
Keyword(s):  
Dose Response ◽  
Prolonged Exposure ◽  
Virus Disease ◽  
Close Contact ◽  
Meta Analysis ◽  
Infected Individual ◽  
Infection Risk ◽  
Transmission Risk ◽  
Effective Control ◽  
Exhaled Breath

Abstract Background A comprehensive understanding of the transmission routes of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of great importance for the effective control of the spread of Corona Virus Disease 2019 (COVID-19). However, the fundamental dose-response relation is still missing for better evaluating and controlling the infection risk. Methods We developed a simple framework to integrate the a priori dose-response relation for SARS-CoV based on mice experiments, the recent data on infection risk from a meta-analysis and the respiratory virus shedding in exhaled breath, to shed light on the dose-response relation for human. The aerosol transmission infection risk was evaluated based on the dose-response model for typical indoor environment. Results The developed dose-response relation is an exponential function with a constant k in the range of about 6.4×10 4 to 9.8×10 5 virus copies, which means that the infection risk caused by one virus copy in viral shedding is on the order of 10 -6 to 10 -5. The median infection risk via aerosol transmission with one-hour exposure (10 -6 to 10 -4) was significantly lower than the risk caused by close contact (10 -1) in a room of the area from 10 to 400 m 2 with one infected individual in it and with typical ventilation rate 1 ACH (Air Changes per Hour). Conclusions The infection risk caused by aerosol transmission was significantly lower than the risk caused by close contact. It is still necessary to be precautious for the potential aerosol transmission risk in small rooms with prolonged exposure duration.

scholarly journals Systematic Review and Meta-Analysis of the Dose-Response and Risk Factors for Obliteration of Arteriovenous Malformations Following Radiosurgery: An Update Based on the Last 20 Years of Published Clinical Evidence

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Shaoyu Zhu ◽  
N Patrik Brodin ◽  
Madhur K Garg ◽  
Patrick A LaSala ◽  
Wolfgang A Tomé
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Dose Response ◽  
Meta Analysis ◽  
Gamma Knife Radiosurgery ◽  
Lesion Size ◽  
Intracranial Arteriovenous Malformation ◽  
Factors Associated ◽  
Obliteration Rate ◽  
Inverse Variance

ABSTRACT BACKGROUND Intracranial arteriovenous malformation (AVM) is a congenital lesion that can potentially lead to devastating consequences if not treated. Many institutional cohort studies have reported on the outcomes after radiosurgery and factors associated with successful obliteration in the last few decades. OBJECTIVE To quantitatively assess the dose-response relationship and risk factors associated with AVM obliteration using a systematic review and meta-analysis approach. METHODS Data were extracted from reports published within the last 20 yr. The dose-response fit for obliteration as a function of marginal dose was performed using inverse-variance weighting. Risk factors for AVM obliteration were assessed by combining odds ratios from individual studies using inverse-variance weighting. RESULTS The logistic model fit showed a clear association between higher marginal dose and higher rates of obliteration. There appeared to be a difference in the steepness in dose-response when comparing studies with patients treated using Gamma Knife radiosurgery (Elekta), compared to linear accelerators (LINACs), and when stratifying studies based on the size of treated AVMs. In the risk-factor analysis, AVM obliteration rate decreases with larger AVM volume or AVM diameter, higher AVM score or Spetzler-Martin (SM) grade, and prior embolization, and increases with compact AVM nidus. No statistically significant associations were found between obliteration rate and age, sex, prior hemorrhage, prior aneurysm, and location eloquence. CONCLUSION A marginal dose above 18 Gy was generally associated with AVM obliteration rates greater than 60%, although lesion size, AVM score, SM grade, prior embolization, and nidus compactness all have significant impact on AVM obliteration rate.

scholarly journals Incidence, risk factors and prognostic effect of imaging right ventricular involvement in patients with COVID-19: a dose–response analysis protocol for systematic review

BMJ Open ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. e049866
Author(s):  
Chenghui Zhou ◽  
Baohui Lou ◽  
Hui Li ◽  
Xin Wang ◽  
Hushan Ao ◽  
...  
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Right Ventricular ◽  
Dose Response ◽  
Meta Analysis ◽  
Adult Patients ◽  
Sensitivity Analyses ◽  
Prognostic Effect ◽  
All Cause Mortality ◽  
Incidence Risk

IntroductionEmerging evidence has shown that COVID-19 infection may result in right ventricular (RV) disturbance and be associated with adverse clinical outcomes. The aim of this meta-analysis is to summarise the incidence, risk factors and the prognostic effect of imaging RV involvement in adult patients with COVID-19.MethodsA systematical search will be performed in PubMed, EMBase, ISI Knowledge via Web of Science and preprint databases (MedRxiv and BioRxiv) (until October 2021) to identify all cohort studies in adult patients with COVID-19. The primary outcome will be the incidence of RV involvement (dysfunction and/or dilation) assessed by echocardiography, CT or MRI. Secondary outcomes will include the risk factors for RV involvement and their association with all-cause mortality during hospitalisation. Additional outcomes will include the RV global or free wall longitudinal strain (RV-GLS or RV-FWLS), tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC) and RV diameter. Univariable or multivariable meta-regression and subgroup analyses will be performed for the study design and patient characteristics (especially acute or chronic pulmonary embolism and pulmonary hypertension). Sensitivity analyses will be used to assess the robustness of our results by removing each included study at one time to obtain and evaluate the remaining overall estimates of RV involvement incidence and related risk factors, association with all-cause mortality, and other RV parameters (RV-GLS or RV-FWLS, TAPSE, S’, FAC and RV diameter). Both linear and cubic spline regression models will be used to explore the dose–response relationship between different categories (>2) of RV involvement and the risk of mortality (OR or HR).Ethics and disseminationThere was no need for ethics approval for the systematic review protocol according to the Institutional Review Board/Independent Ethics Committee of Fuwai Hospital. This meta-analysis will be disseminated through a peer-reviewed journal for publication.PROSPERO registration numberCRD42021231689.

scholarly journals Dietary and circulating vitamin C, vitamin E, β-carotene and risk of total cardiovascular mortality: a systematic review and dose–response meta-analysis of prospective observational studies

2019 ◽  
Vol 22 (10) ◽  
pp. 1872-1887 ◽  
Author(s):  
Ahmad Jayedi ◽  
Ali Rashidy-Pour ◽  
Mohammad Parohan ◽  
Mahdieh Sadat Zargar ◽  
Sakineh Shab-Bidar
Keyword(s):  
Systematic Review ◽  
Vitamin E ◽  
Vitamin C ◽  
Dose Response ◽  
Observational Studies ◽  
Meta Analysis ◽  
Dietary Intakes ◽  
Relative Risks ◽  
Β Carotene ◽  
Cvd Mortality

AbstractObjectiveThe present review aimed to quantify the association of dietary intake and circulating concentration of major dietary antioxidants with risk of total CVD mortality.DesignSystematic review and meta-analysis.SettingSystematic search in PubMed and Scopus, up to October 2017.ParticipantsProspective observational studies reporting risk estimates of CVD mortality across three or more categories of dietary intakes and/or circulating concentrations of vitamin C, vitamin E and β-carotene were included. A random-effects meta-analysis was conducted.ResultsA total of fifteen prospective cohort studies and three prospective evaluations within interventional studies (320 548 participants and 16 974 cases) were analysed. The relative risks of CVD mortality for the highest v. the lowest category of antioxidant intakes were as follows: vitamin C, 0·79 (95 % CI 0·68, 0·89; I2=46 %, n 10); vitamin E, 0·91 (95 % CI 0·79, 1·03; I2=51 %, n 8); β-carotene, 0·89 (95 % CI 0·73, 1·05; I2=34 %, n 4). The relative risks for circulating concentrations were: vitamin C, 0·60 (95 % CI 0·42, 0·78; I2=65 %, n 6); α-tocopherol, 0·82 (95 % CI 0·76, 0·88; I2=0 %, n 5); β-carotene, 0·68 (95 % CI 0·52, 0·83; I2=50 %, n 6). Dose–response meta-analyses demonstrated that the circulating biomarkers of antioxidants were more strongly associated with risk of CVD mortality than dietary intakes.ConclusionsThe present meta-analysis demonstrates that higher vitamin C intake and higher circulating concentrations of vitamin C, vitamin E and β-carotene are associated with a lower risk of CVD mortality.

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