scholarly journals A Covid-19 case mortality rate without time delay systematics

2020 ◽  
Author(s):  
Richard Lieu ◽  
Siobhan Quenby ◽  
Ally Bi-Zhu Jiang
Keyword(s):  
Time Delay ◽  
Mortality Rate ◽  
Systematic Error ◽  
Detailed Knowledge ◽  
Cumulative Number ◽  
Daily Number ◽  
Delay Distribution ◽  
The Mean ◽  
Case Mortality

AbstractConcerning the two approaches to the Covid-19 case mortality rate published in the literature, namely computing the ratio of (a) the daily number of deaths to a time delayed daily number of confirmed infections; and (b) the cumulative number of deaths to confirmed infections up to a certain time, both numbers having been acquired in the middle of an outbreak, it is shown that each suffers from systematic error of a different source. We further show that in the absence of detailed knowledge of the time delay distribution of (a), the true case mortality rate is obtained by pursuing method (b) at the end of the outbreak when the fate of every case has decisively been rendered. The approach is then employed to calculate the mean case mortality rate of 13 regions of China where every case has already been resolved. This leads to a mean rate of 0.527 ± 0.001 %.

The global dynamics of stochastic Holling type II predator-prey models with non constant mortality rate

Filomat ◽  
2017 ◽  
Vol 31 (18) ◽  
pp. 5811-5825
Author(s):  
Xinhong Zhang
Keyword(s):  
Mortality Rate ◽  
Stochastic Model ◽  
Sufficient Conditions ◽  
Positive Periodic Solution ◽  
Global Dynamics ◽  
Type Ii ◽  
Predator Prey ◽  
Persistence In The Mean ◽  
The Mean ◽  
Predator Prey Models

In this paper we study the global dynamics of stochastic predator-prey models with non constant mortality rate and Holling type II response. Concretely, we establish sufficient conditions for the extinction and persistence in the mean of autonomous stochastic model and obtain a critical value between them. Then by constructing appropriate Lyapunov functions, we prove that there is a nontrivial positive periodic solution to the non-autonomous stochastic model. Finally, numerical examples are introduced to illustrate the results developed.

Aflibercept in real-life for the treatment of age-related macular degeneration using a treat and extend protocol: The Armada study

2021 ◽  
pp. 112067212110057
Author(s):  
Pierre Gascon ◽  
Prithvi Ramtohul ◽  
Charles Delaporte ◽  
Sébastien Kerever ◽  
Danièle Denis ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Real Life ◽  
Age Related Macular Degeneration ◽  
Cumulative Number ◽  
Treat And Extend ◽  
Treatment Interval ◽  
Age Related ◽  
Treatment Naïve ◽  
The Mean

Purpose: To report the visual and anatomic outcomes in treatment-naïve neovascular age-related macular degeneration (nAMD) patients treated with aflibercept under a standardized Treat and Extend (T&E) protocol for up to 3 years of follow-up in “real-life” practice. Methods: This retrospective, observational, multicenter study included patients with treatment-naïve nAMD and at least 12 months of follow-up. T&E regimen adjustment was initiated after loading phase. At each visit best-corrected visual acuity (BCVA) and optical coherence tomography parameters were performed. Results: One hundred and thirty-six eyes of 115patients had at least 1 year of follow-up with 114 and 82 eyes completing at least 2 and 3 years of follow-up, respectively (mean follow-up duration: 2.7 ± 1.3 years). Mean age was 78.6 ± 8.6 years old and 52% were women. Mean BCVA increased from 60.6 ± 18.7 letters at diagnosis to 66.9 ± 16.2 letters at 1 year (+6.3 letters, p = 0.003) and remained stable throughout the follow-up period (63.1 ± 20.3 letters (+2.5, p = 0.1) and 64.0 ± 20.1 letters (+3.4, p = 0.27) at 2 and 3 years, respectively). The mean central retinal thickness decreased significantly from 358.2 ± 87.9 µm at baseline to 302 ± 71.7 µm at 12 months and maintained stable after 36 months of follow-up (297.1 ± 76 µm, p < 0.0001). Mean number of injections was 6.6 ± 2.2, 4.8 ± 1.9, and 5.6 ± 1.7 at 1, 2, and 3 years, respectively. Mean cumulative number of 16.4 ± 5.6 injections after 3 years. Mean treatment interval was 6.8 ± 2.5 weeks at 1 year. Eight-week and 12-week treatment interval were achieved in 59.5% and 19.1%, 65.8%, and 36.8% and 69.5% and 41.5% at 1, 2, and 3 years, respectively. Conclusions: Our study demonstrated that intravitreal injections of aflibercept initiated under a standardized T&E for patients with treatment-naïve nAMD allow for significant visual improvement at 12 months, which was maintained over a 3-year follow-up period.

scholarly journals Country-level determinants of the severity of the first global wave of the COVID-19 pandemic: an ecological study

BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e042034
Author(s):  
Tiberiu A Pana ◽  
Sohinee Bhattacharya ◽  
David T Gamble ◽  
Zahra Pasdar ◽  
Weronika A Szlachetka ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Vaccination Coverage ◽  
Urban Areas ◽  
Ecological Study ◽  
Environmental Parameters ◽  
The Philippines ◽  
International Travel ◽  
Bcg Vaccination ◽  
Country Level ◽  
The Mean

ObjectiveWe aimed to identify the country-level determinants of the severity of the first wave of the COVID-19 pandemic.DesignEcological study of publicly available data. Countries reporting >25 COVID-19 related deaths until 8 June 2020 were included. The outcome was log mean mortality rate from COVID-19, an estimate of the country-level daily increase in reported deaths during the ascending phase of the epidemic curve. Potential determinants assessed were most recently published demographic parameters (population and population density, percentage population living in urban areas, population >65 years, average body mass index and smoking prevalence); economic parameters (gross domestic product per capita); environmental parameters (pollution levels and mean temperature (January–May); comorbidities (prevalence of diabetes, hypertension and cancer); health system parameters (WHO Health Index and hospital beds per 10 000 population); international arrivals; the stringency index, as a measure of country-level response to COVID-19; BCG vaccination coverage; UV radiation exposure; and testing capacity. Multivariable linear regression was used to analyse the data.Primary outcomeCountry-level mean mortality rate: the mean slope of the COVID-19 mortality curve during its ascending phase.ParticipantsThirty-seven countries were included: Algeria, Argentina, Austria, Belgium, Brazil, Canada, Chile, Colombia, the Dominican Republic, Ecuador, Egypt, Finland, France, Germany, Hungary, India, Indonesia, Ireland, Italy, Japan, Mexico, the Netherlands, Peru, the Philippines, Poland, Portugal, Romania, the Russian Federation, Saudi Arabia, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, the UK and the USA.ResultsOf all country-level determinants included in the multivariable model, total number of international arrivals (beta 0.033 (95% CI 0.012 to 0.054)) and BCG vaccination coverage (−0.018 (95% CI −0.034 to –0.002)), were significantly associated with the natural logarithm of the mean death rate.ConclusionsInternational travel was directly associated with the mortality slope and thus potentially the spread of COVID-19. Very early restrictions on international travel should be considered to control COVID-19 outbreaks and prevent related deaths.

scholarly journals Acute coronary syndrome: which age group tends to delay call for help?

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Ahmed Ayuna ◽  
Ayyaz Sultan
Keyword(s):  
Acute Coronary Syndrome ◽  
Time Delay ◽  
Local Population ◽  
Age Groups ◽  
Age Group ◽  
Teaching Programme ◽  
The Road ◽  
Coronary Syndrome ◽  
The Mean ◽  
Mean Time

Abstract Background Early diagnosis and treatment of ACS can reduce the risk of complications and death. Delay calling for help can increase morbidity and mortality. It is unclear which age group among patients with acute coronary syndrome tend to delay their call for help. Results Our observational retrospective study showed that men and women in their 50s and 40s respectively tend to delay their call for help from symptoms onset. For the former, the mean time delays (590 ± 71.1 min), whereas for the latter it was (1084 ± 120.1 min). Moreover, these groups tend to have a longer time delay between symptoms onset and arrival at the hospital. Among deaths, we observed that the death rate was proportional to the time delay, which is not unexpected. Next step, we plan to perform a qualitative study in the form of questionnaires to target the individuals with a high risk of CVD within these age groups. Conclusion Middle age group of both genders tend to delay their call for help when they experience symptoms of ACS; moreover, regardless of the age, the longer the delay, the higher the mortality rate. The results of this study gave us a better understanding of our local population and will pave the road for a well-structured teaching programme for them to minimise the time delay for calling for help.

scholarly journals Early mortality in hip fracture patients admitted during first wave of the COVID-19 pandemic in Northern Italy: a multicentre study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Dante Dallari ◽  
Luigi Zagra ◽  
Pietro Cimatti ◽  
Nicola Guindani ◽  
Rocco D’Apolito ◽  
...  
Keyword(s):  
Hip Fracture ◽  
Mortality Rate ◽  
Multicentre Study ◽  
Proximal Femur ◽  
Femur Fracture ◽  
Northern Italy ◽  
Proximal Femur Fracture ◽  
Time To Surgery ◽  
Fracture Management ◽  
The Mean

Abstract Background Treatment of hip fractures during the coronavirus disease 2019 (COVID-19) pandemic has posed unique challenges for the management of COVID-19-infected patients and the maintenance of standards of care. The primary endpoint of this study is to compare the mortality rate at 1 month after surgery in symptomatic COVID-positive patients with that of asymptomatic patients. A secondary endpoint of the study is to evaluate, in the two groups of patients, mortality at 1 month on the basis of type of fracture and type of surgical treatment. Materials and methods For this retrospective multicentre study, we reviewed the medical records of patients hospitalised for proximal femur fracture at 14 hospitals in Northern Italy. Two groups were formed: COVID-19-positive patients (C+ group) presented symptoms, had a positive swab for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and received treatment for COVID-19; COVID-19-negative patients (C− group) were asymptomatic and tested negative for SARS-CoV-2. The two groups were compared for differences in time to surgery, survival rate and complications rate. The follow-up period was 1 month. Results Of the 1390 patients admitted for acute care for any reason, 477 had a proximal femur fracture; 53 were C+ but only 12/53 were diagnosed as such at admission. The mean age was > 80 years, and the mean American Society of Anesthesiologists (ASA) score was 3 in both groups. There was no substantial difference in time to surgery (on average, 2.3 days for the C+ group and 2.8 for the C− group). As expected, a higher mortality rate was recorded for the C+ group but not associated with the type of hip fracture or treatment. No correlation was found between early treatment (< 48 h to surgery) and better outcome in the C+ group. Conclusions Hip fracture in COVID-19-positive patients accounted for 11% of the total. On average, the time to surgery was > 48 h, which reflects the difficulty of maintaining normal workflow during a medical emergency such as the present pandemic and notwithstanding the suspension of non-urgent procedures. Hip fracture was associated with a higher 30-day mortality rate in COVID-19-positive patients than in COVID-19-negative patients. This fact should be considered when communicating with patients and/or their family. Our data suggest no substantial difference in hip fracture management between patients with or without COVID-19 infection. In this sample, the COVID-19-positive patients were generally asymptomatic at admission; therefore, routine screening is recommended. Level of evidence Therapeutic study, level 4.

scholarly journals Universality of the Wigner Time Delay Distribution for One-Dimensional Random Potentials

1999 ◽  
Vol 82 (21) ◽  
pp. 4220-4223 ◽  
Author(s):  
Christophe Texier ◽  
Alain Comtet
Keyword(s):  
Time Delay ◽  
Random Potentials ◽  
One Dimensional ◽  
Delay Distribution

scholarly journals Prevalence of multidrug-resistant Acinetobacter baumannii in a critical care setting: A tertiary teaching hospital experience

2021 ◽  
Vol 9 ◽  
pp. 205031212110011
Author(s):  
Thabit Alotaibi ◽  
Abdulrhman Abuhaimed ◽  
Mohammed Alshahrani ◽  
Ahmed Albdelhady ◽  
Yousef Almubarak ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Mortality Rate ◽  
Acinetobacter Baumannii ◽  
Care Setting ◽  
Multidrug Resistant ◽  
University Hospital ◽  
Published Data ◽  
Tertiary Teaching ◽  
The Mean

Background: The management of Acinetobacter baumannii infection is considered a challenge especially in an intensive care setting. The resistance rate makes it difficult to manage and is believed to lead to higher mortality. We aim to investigate the prevalence of Acinetobacter baumannii and explore how different antibiotic regimens could impact patient outcomes as there are no available published data to reflect our population in our region. Methods: We conducted a retrospective review of all infected adult patients admitted to the intensive care unit at King Fahad University Hospital with a confirmed laboratory diagnosis of Acinetobacter baumannii from 1 January 2013 until 31 December 2017. Positive cultures were obtained from the microbiology department and those meeting the inclusive criteria were selected. Variables were analyzed using descriptive analysis and cross-tabulation. Results were further reviewed and audited by blinded co-authors. Results: A comprehensive review of data identified 198 patients with Acinetobacter baumannii. The prevalence of Acinetobacter baumannii is 3.37%, and the overall mortality rate is 40.81%. Our sample consisted mainly of male patients, that is, 68.7%, with a mean age of 49 years, and the mean age of female patients was 56 years. The mean age of survivors was less than that of non-survivors, that is, 44.95 years of age. We observed that prior antibiotic use was higher in non-survivors compared to survivors. From the review of treatment provided for patients infected with Acinetobacter baumannii, 65 were treated with colistin alone, 18 were treated with carbapenems, and 22 were treated with a combination of both carbapenems and colistin. The mean length of stay of Acinetobacter baumannii–infected patients was 20.25 days. We found that the survival rates among patients who received carbapenems were higher compared to those who received colistin. Conclusion: We believe that multidrug-resistant Acinetobacter baumannii is prevalent and associated with a higher mortality rate and represents a challenging case for every intensive care unit physician. Further prospective studies are needed.

Treatment of Severe Apnea in Prematures With Orally Administered Theophylline

PEDIATRICS ◽  
1975 ◽  
Vol 55 (5) ◽  
pp. 595-598
Author(s):  
Ricardo Uauy ◽  
Donald L. Shapiro ◽  
Barbara Smith ◽  
Joseph B. Warshaw
Keyword(s):  
Heart Rate ◽  
Mechanical Ventilation ◽  
Premature Infants ◽  
Side Effect ◽  
Significant Side Effect ◽  
Daily Number ◽  
The Mean

Twelve premature infants with primary apnea were treated with theophylline as an alternative to mechanical ventilation. There was a significant (P&lt; .005) reduction in the mean daily number and the severity of apneic episodes after treatment. The only significant side effect noted was a rise in heart rate.

scholarly journals Mean first-passage time of a tumor cell growth system with time delay and colored cross-correlated noises excitation

2017 ◽  
Vol 37 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Shenghong Li ◽  
Yong Huang
Keyword(s):  
Time Delay ◽  
Noise Intensity ◽  
First Passage Time ◽  
Passage Time ◽  
Mean First Passage Time ◽  
Tumor Cell Growth ◽  
First Passage ◽  
Growth System ◽  
The Mean ◽  
Correlated Noises

In this paper, the mean first-passage time of a delayed tumor cell growth system driven by colored cross-correlated noises is investigated. Based on the Novikov theorem and the method of probability density approximation, the stationary probability density function is obtained. Then applying the fastest descent method, the analytical expression of the mean first-passage time is derived. Finally, effects of different kinds of delays and noise parameters on the mean first-passage time are discussed thoroughly. The results show that the time delay included in the random force, additive noise intensity and multiplicative noise intensity play a positive role in the disappearance of tumor cells. However, the time delay included in the determined force and the correlation time lead to the increase of tumor cells.

scholarly journals Indications of admitting patients in internal ICU and the rate of mortality in Emam Khomeini hospital in 2013

2019 ◽  
Vol 6 (6) ◽  
pp. 2335
Author(s):  
Hasan Ghobadi ◽  
Shahram Habibzadeh ◽  
Bita Shahbazzadegan ◽  
Mohsen Mirzanezhadasl ◽  
Mahsa Kamranimoghaddam
Keyword(s):  
Mortality Rate ◽  
Continuous Monitoring ◽  
Good Condition ◽  
Vital Signs ◽  
The Public ◽  
Special Services ◽  
Disease Prognosis ◽  
Significant Difference ◽  
The Mean ◽  
End Stage

Background: ICU is the costly part of the hospital that has functional approach for patients who have reversible conditions so it needs mechanical ventilation and other special services. Some patients are not really in need of special care only the continuous monitoring of vital signs needs of the public sector. Patients with good condition or End-Stage were not candidate to admitting in ICU. The aim of this study was to evaluate indications of admitting patients in internal ICU and the rate of mortality in Emam Khomeini hospital in 2013.Methods: The study was conducted retrospectively evaluated the records of patients hospitalized in ICU and disease prognosis and treatment of disease and APACHE2 criteria was analyses.Results: The mean age of patients in the study was 61.05±19.81. Of 118 patients, 70 (59.3%) survived and 48 (40.7%) patients died. APACHE2 mean in the study was 21.46±7.5. GCS average was 9.83±4.27. There was correlation between mortality of patients and type of disease. In this study in APACHE2 score between 25-29 and >35 in mortality rate we are higher than standard average and in 10-14 and 20-24 we are lower than standard average.Conclusions: This study shows that GCS is not a good measure for the evaluation of patients hospitalized in internal ICU. In the present study, patients with higher APACHE2 score of 35 died. That show hospitalization that patient in ICU has no difference in the prognosis of them. As regards mortality rate in ICU patients in this study has no significant difference with predicted APACHE values, indications of ICU admition in Emam Khomeini hospital observed exactly.

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