scholarly journals Predicting COVID-19 cases with unknown homogeneous or heterogeneous resistance to infectivity

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254313
Author(s):  
Ramalingam Shanmugam ◽  
Gerald Ledlow ◽  
Karan P. Singh
Keyword(s):  
Health System ◽  
Infection Rate ◽  
Negative Correlation ◽  
Infectivity Rate ◽  
System Memory ◽  
The Mean ◽  
Hazard Level ◽  
Family Gathering ◽  
Cluster 2 ◽  
Refined Version

We present a restricted infection rate inverse binomial-based approach to better predict COVID-19 cases after a family gathering. The traditional inverse binomial (IB) model is inappropriate to match the reality of COVID-19, because the collected data contradicts the model’s requirement that variance should be larger than the expected value. Our version of an IB model is more appropriate, as it can accommodate all potential data scenarios in which the variance is smaller, equal, or larger than the mean. This is unlike the usual IB, which accommodates only the scenario in which the variance is more than the mean. Therefore, we propose a refined version of an IB model to be able to accommodate all potential data scenarios. The application of the approach is based on a restricted infectivity rate and methodology on COVID-19 data, which exhibit two clusters of infectivity. Cluster 1 has a smaller number of primary cases and exhibits larger variance than the expected cases with a negative correlation of 28%, implying that the number of secondary cases is lesser when the number of primary cases increases and vice versa. The traditional IB model is appropriate for Cluster 1. The probability of contracting COVID-19 is estimated to be 0.13 among the primary, but is 0.75 among the secondary in Cluster 1, with a wider gap. Cluster 2, with a larger number of primary cases, exhibits smaller variance than the expected cases with a correlation of 79%, implying that the number of primary and secondary cases do increase or decrease together. Cluster 2 disqualifies the traditional IB model and requires its refined version. The probability of contracting COVID-19 is estimated to be 0.74 among the primary, but is 0.72 among the secondary in Cluster 2, with a narrower gap. The advantages of the proposed approach include the model’s ability to estimate the community’s health system memory, as future policies might reduce COVID’s spread. In our approach, the current hazard level to be infected with COVID-19 and the odds of not contracting COVID-19 among the primary in comparison to the secondary groups are estimable and interpretable.

scholarly journals Predicting COVID-19 cases with unknown homogeneous or heterogeneous resistance to infectivity

2020 ◽  
Author(s):  
Ramalingam Shanmugam ◽  
Gerald Ledlow ◽  
Karan P. Singh
Keyword(s):  
Health System ◽  
Statistical Models ◽  
Expected Value ◽  
Social Events ◽  
Infectivity Rate ◽  
System Memory ◽  
Hazard Level ◽  
Family Gathering ◽  
Cluster 2 ◽  
Refined Version

AbstractThis article constructs a restricted infection rate inverse binomial-based approach to predict COVID-19 cases after a family gathering. The traditional inverse binomial (IB) model is unqualified to match the reality of COVID-19, because the data contradicts the model’s requirement that variance should be greater than expected value. A refined version of the IB model is a necessity to predict COVID-19 cases after family gatherings. Our refined version of an IB model is more appropriate and versatile, as it accommodates all potential data scenarios: equal, lesser, or greater variance than expected value.Application of the approach is based on a restricted infectivity rate and methodology on Fan et al.’s COVID-19 data, which exhibits two clusters of infectivity. Cluster 1 has a smaller number of primary cases and exhibits larger variance than the expected cases with a negative correlation of 28%, implying that the number of secondary cases is lesser when the number of primary cases increases and vice versa. The traditional inverse binomial (IB) model is appropriate for Cluster 1. The probability of contracting COVID-19 is estimated to be 0.13 among the primary, but is 0.75 among the secondary in Cluster 1, with a wider gap. Conversely, Cluster 2, exhibits smaller variance than the expected cases with a correlation of 79%, implying the number of primary and secondary cases increase or decrease together. Cluster 2 disqualifies the traditional IB model and demands its refined version. Probability of contracting COVID-19 is estimated to be 0.74 among the primary, but is 0.72 among the secondary in Cluster 2, with a narrower gap.The model’s ability to estimate the community’s health system memory for future policies to be developed is an asset of this approach. The current hazard level to be infected with COVID-19 among the primary and secondary groups are estimable and interpretable.Author SummaryCurrent statistical models are not able to accurately predict disease infection spread in the COVID-19 pandemic. We have applied a widely-used inverse binomial method to predict rates of infection after small gatherings, going from primary (original) cases to secondary (later) cases after family gatherings or social events, using the data from the Wuhan and Gansu provinces in China, where the virus first spread. The advantages of the proposed approach include that the model’s ability to estimate the community’s health system memory for future policies to be developed, as such policies might reduce COVID’s spread if not its control. In our approach, as demonstrated, the current hazard level of becoming infected with COVID-19 and the odds of contracting COVID-19 among the primary in comparison to the secondary groups are estimable and interpretable. We hope the proposed approach will be used in future epidemics.

RELATIONSHIP BETWEEN CARDIOVASCULAR DISEASES AND ANATOMOSIS OF ARTERIOVENOUS FISTULAR IN PATIENTS WITH REGULARLY HEMODIALYSIS

2017 ◽  
pp. 88-92
Author(s):  
Van Hien Pham ◽  
Huu Vu Quang Nguyen ◽  
Tam Vo
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Renal Failure ◽  
Chronic Renal Failure ◽  
Cardiovascular Diseases ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Negative Correlation ◽  
Mean Value ◽  
The Mean

Background: Cardiovascular diseases are the leading cause of death in patients with chronic renal failure. When a patient undergoes dialysis, making AVF or AVG causes cardiovascular events. Understanding the relationship between complications: hypertension, heart failure, AVF or AVG (formation time, position, diameter) helps us monitor, detect, prevent and treatment of complications to limit the risk of death in patients with dialysis. Objective: Relationship between cardiovascular diseases and anatomosis of arteriovenous fistular in patients with regularly hemodialysis at Cho Ray Hospital. Methods: A cross-sectional study was conducted at Cho Ray Hospital from 2015 to 2016. The survey some cardiovascular diseases are done by clinical examination, tests for diagnostic imaging such as X-ray, electrocardiogram and echocardiogram: heart and diameter of anastomosis AVF, AVG. Results: The study population included 303 patients with chronic renal failure who were dialysis. Of which, patients aged 25-45 accounted for the highest proportion (43.9%). The proportion of male and female patients was similar (48.5% and 51.5% respectively). The mean value of systolic blood pressure on patients made AVF, AVG less than 12 months is higher than patients made AVF, AVG over 12 months, and there is negative correlation (r = -0.43) between AVF, AVG and systolic blood pressure (p <0.05). The mean value of diastolic blood pressure on patients made AVF, AVG less than 12 months is lower than patients made AVF, AVG over 12 months, and and there is positive correlation (r = -0.43) between AVF, AVG and diastolic blood pressure (p <0.05) (p <0.05). The prevalence of patients with heart failure made AVF, AVG over 12 months is higher than that of the under 12 months group, there is a negative correlation (r = - 0.43) between AVF, AVG diameter and EF index (p <0.05). Conclusion: It is important to note the diameter of anastomosis AVF, AVG in patients with chronic renal failure dialysis to limit cardiovascular complications, especially heart failure. Key words: Chronic kidney disease, hemodialysis.

scholarly journals P170 The validity and utility of the SLE-key® rule-out serological test when applied in a selected cohort of patients with SLE and other connective tissue diseases

Rheumatology ◽  
2021 ◽  
Vol 60 (Supplement_1) ◽  
Author(s):  
Sheilla Achieng ◽  
John A Reynolds ◽  
Ian N Bruce ◽  
Marwan Bukhari
Keyword(s):  
Linear Regression ◽  
Connective Tissue ◽  
Connective Tissue Disease ◽  
Negative Correlation ◽  
Connective Tissue Diseases ◽  
Inflammatory Myositis ◽  
The Mean ◽  
Negative Rule ◽  
Spearman’S Correlation ◽  
Rule Out

Abstract Background/Aims  We aimed to establish the validity of the SLE-key® rule-out test and analyse its utility in distinguishing systemic lupus erythematosus (SLE) from other autoimmune rheumatic connective tissue diseases. Methods  We used data from the Lupus Extended Autoimmune Phenotype (LEAP) study, which included a representative cross-sectional sample of patients with a variety of rheumatic connective tissue diseases, including SLE, mixed connective tissue disease (MCTD), inflammatory myositis, systemic sclerosis, primary Sjögren’s syndrome and undifferentiated connective tissue disease (UCTD). The modified 1997 ACR criteria were used to classify patients with SLE. Banked serum samples were sent to Immune-Array’s CLIA- certified laboratory Veracis (Richmond, VA) for testing. Patients were assigned test scores between 0 and 1 where a score of 0 was considered a negative rule-out test (i.e. SLE cannot be excluded) whilst a score of 1 was assigned for a positive rule-out test (i.e. SLE excluded). Performance measures were used to assess the test’s validity and measures of association determined using linear regression and Spearman’s correlation. Results  Our study included a total of 155 patients of whom 66 had SLE. The mean age in the SLE group was 44.2 years (SD 13.04). 146 patients (94.1%) were female. 84 (54.2%) patients from the entire cohort had ACR SLE scores of ≤ 3 whilst 71 (45.8%) had ACR SLE scores ≥ 4. The mean ACR SLE total score for the SLE patients was 4.85 (SD 1.67), ranging from 2 to 8, with mean disease duration of 12.9 years. The Sensitivity of the SLE-Key® Rule-Out test in diagnosing SLE from other connective tissue diseases was 54.5%, specificity was 44.9%, PPV 42.4% and NPV 57.1 %. 45% of the SLE patients had a positive rule-out test. SLE could not be ruled out in 73% of the MCTD patients whilst 51% of the UCTD patients had a positive Rule-Out test and &gt;85% of the inflammatory myositis patients had a negative rule-out test. ROC analysis generated an AUC of 0.525 illustrating weak class separation capacity. Linear regression established a negative correlation between the SLE-key Rule-Out score and ACR SLE total scores. Spearman’s correlation was run to determine the relationship between ACR SLE total scores and SLE-key rule-out score and showed very weak negative correlation (rs = -0.0815, n = 155, p = 0.313). Conclusion  Our findings demonstrate that when applied in clinical practice in a rheumatology CTD clinic setting, the SLE-key® rule-out test does not accurately distinguish SLE from other CTDs. The development of a robust test that could achieve this would be pivotal. It is however important to highlight that the test was designed to distinguish healthy subjects from SLE patients and not for the purpose of differentiating SLE from other connective tissue diseases. Disclosure  S. Achieng: None. J.A. Reynolds: None. I.N. Bruce: Other; I.N.B is a National Institute for Health Research (NIHR) Senior Investigator and is funded by the NIHR Manchester Biomedical Research Centre. M. Bukhari: None.

scholarly journals The impact of quarantine on Covid-19 infections

2021 ◽  
Vol 10 (s1) ◽  
Author(s):  
Pablo Marshall
Keyword(s):  
Health System ◽  
Infection Rate ◽  
District Level ◽  
Infection Model ◽  
Social Distancing ◽  
Proposed Model ◽  
Lower Infection ◽  
The Impact ◽  
Lower Infection Rate ◽  
Over Time

Abstract Objectives: Coronavirushas had profound effects on people’s lives and the economy of many countries, generating controversy between the need to establish quarantines and other social distancing measures to protect people’s health and the need to reactivate the economy. This study proposes and applies a modification of the SIR infection model to describe the evolution of coronavirus infections and to measure the effect of quarantine on the number of people infected. Methods: Two hypotheses, not necessarily mutually exclusive, are proposed for the impact of quarantines. According to the first hypothesis, quarantine reduces the infection rate, delaying new infections over time without modifying the total number of people infected at the end of the wave. The second hypothesis establishes that quarantine reduces the population infected in the wave. The two hypotheses are tested with data for a sample of 10 districts in Santiago, Chile. Results: The results of applying the methodology show that the proposed model describes well the evolution of infections at the district level. The data shows evidence in favor of the first hypothesis, quarantine reduces the infection rate; and not in favor of the second hypothesis, that quarantine reduces the population infected. Districts of higher socio-economic levels have a lower infection rate, and quarantine is more effective. Conclusions: Quarantine, in most districts, does not reduce the total number of people infected in the wave; it only reduces the rate at which they are infected. The reduction in the infection rate avoids peaks that may collapse the health system.

93 Does Spinal Bone Mineral Density Predict An Absolute 10 Year Probability of Sustaining A Major Osteoporotic Fracture

2021 ◽  
Vol 50 (Supplement_1) ◽  
pp. i12-i42
Author(s):  
A Nandi ◽  
N Obiechina ◽  
A Timperley ◽  
F Al-Khalidi
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Osteoporotic Fracture ◽  
Negative Correlation ◽  
Pearson Correlation ◽  
Fragility Fractures ◽  
Mineral Density ◽  
Major Osteoporotic Fracture ◽  
T Score ◽  
The Mean

Abstract Introduction Spine and hip bone mineral density (BMD) have previously been shown to predict the risk of sustaining future fractures. Although these have been shown in population studies, there is a paucity of trials looking at the relationship between BMD and 10 year probability of major osteoporotic fractures (Using FRAX UK without BMD) in patients with previous fragility fractures. Aims To evaluate the correlation between spinal T-score and an absolute 10 year probability of sustaining a major osteoporotic fracture (using FRAX without BMD) in patients with prior fragility fractures. Methods A retrospective cross-sectional analysis of 202 patients (29 males and 173 females) with prior fragility fractures attending a fracture prevention clinic between January and August 2019 was performed. Patients with pathological and high impact traumatic fractures were excluded. The BMD at the spine was determined using the lowest T-score of the vertebrae from L1 to L4. Using the FRAX (UK) without BMD, the absolute 10 year probability of sustaining a major osteoporotic fracture was calculated for each patient. Statistical analysis was performed using SPSS 26 software. Results The mean T-score at the spine was −1.15 (SD +/− 1.90) for all patients, −0.68 (SD +/− 0.45) for males and − 1.23 (SD +/− 0.14) for females. The mean FRAX score without BMD for major osteoporotic fracture was 18.5% (SD +/− 8.84) for all patients, 11.41% (SD +/−0.62) and 19.7% (SD +/−0.68) for males and females respectively. Pearson correlation coefficient showed a statistically significant, slightly negative correlation between spinal T- score and the FRAX (UK) without BMD (r = −0.157; p &lt; 0.05). Correlation was not statistically significant when males (r = 0.109; p = 0.59) and females (r = 0.148; p = 0.053) were considered independently. Conclusion In patients with prior fragility fracture spinal BMD has a statistically significant negative correlation with an absolute 10 year probability of sustaining a major osteoporotic fracture.

scholarly journals The Mean Square Error of Prediction in the Chain Ladder Reserving Method – A Comment

2006 ◽  
Vol 36 (02) ◽  
pp. 543-552 ◽  
Author(s):  
Thomas Mack ◽  
Gerhard Quarg ◽  
Christian Braun
Keyword(s):  
Mean Square Error ◽  
Negative Correlation ◽  
Mean Square ◽  
New Approach ◽  
The Mean ◽  
Chain Ladder ◽  
Original Formula

We discuss some questionable points of the approach taken in the paper by Buchwalder, Bühlmann, Merz and Wüthrich and come to the conclusion that this approach does not yield an improvement of Mack’s original formula. The main reason is that the new approach disregards the negative correlation of the squares of the development factors. The same applies to the formula by Murphy (PCAS 1994).

scholarly journals Correlation between smoking and neovascularization in biceps tendinopathy: a functional preoperative and immunohistochemical study

2020 ◽  
Vol 11 ◽  
pp. 204062232095641
Author(s):  
Jan Zabrzynski ◽  
Maciej Gagat ◽  
Lukasz Paczesny ◽  
Dariusz Grzanka ◽  
Gazi Huri
Keyword(s):  
Negative Correlation ◽  
Immunohistochemical Study ◽  
Biceps Tendon ◽  
Smoking History ◽  
Tissue Samples ◽  
Biceps Tenotomy ◽  
Preoperative Status ◽  
Former Smokers ◽  
The Mean ◽  
Long Head

Aims: The purpose of this study was to investigate whether smoking is associated with neovascularization in the tendinopathy of the long head of the biceps tendon (LHBT). Methods: The study included 40 consecutive patients who underwent arthroscopic biceps tenotomy/tenodesis due to chronic biceps tendinopathy and divided into three groups: (1) non-smokers, (2) former smokers, (3) smokers. LHBT tissue samples were stained with H&E, Alcian blue and Trichrome staining. Immunohistochemical examination was performed using anti-CD31 and anti-CD34. The neovessel density score (NDS) was scored by Bonar criteria. Results: The mean period of smoking was 15.50 years with an average number of 24 cigarettes/day in the former smokers and 21.69 years with an average number of 15 cigarettes/day in the active smokers. The mean NDS was 2.23/3 in non-smokers, whereas it was 1.60/3 in former smokers and 1.31/3 in active smokers. The mean American Shoulder and Elbow Surgeons score equaled 46 in never smoked patients, 43.60 in former smokers, and 41.46 in active smokers. In the patients with smoking history, the disorganized tendinous tissue islands were avascular and composed of compact acidic polysaccharides and mucopolysaccharides. We observed negative correlation between the NDS and the smoking indexes, including cigarettes per day ( p = 0.0150), smoking years ( p = 0.0140), pack-years ( p = 0.0088). Conclusion: In conclusion, the present study revealed that smoking impairs the vascularization of the biceps tendon in chronic tendinopathy. Clinically, we observed a negative correlation between smoking and neovascularization. Furthermore, there was no correlation between neovascularization and functional preoperative status.

Cross-correlation of cyclosporine concentrations and biochemical measures of kidney and liver function in heart and heart-lung transplant recipients

1990 ◽  
Vol 36 (8) ◽  
pp. 1474-1478 ◽  
Author(s):  
A Trull ◽  
K Hue ◽  
K Tan ◽  
S Gore ◽  
S Whitewood ◽  
...  
Keyword(s):  
Renal Function ◽  
Liver Function ◽  
Correlation Coefficient ◽  
Negative Correlation ◽  
Whole Blood ◽  
Lung Transplant ◽  
Cross Correlation ◽  
Transplant Recipients ◽  
The Mean ◽  
Lung Transplant Recipients

Abstract Cross-correlation of cyclosporine concentrations with results of biochemical tests of renal and liver function, measured during the first three months post-operatively, was carried out retrospectively in 24 heart and eight heart-lung transplant recipients to assess the temporal relationship between cyclosporine treatment and the development of possible toxic side-effects. We found a statistically significant negative correlation (95% confidence interval of the mean correlation coefficient did not overlap zero) between the five-day mean concentration of cyclosporine in whole blood (but not plasma) as measured with nonselective (NSRIA) and selective radioimmunoassays (SRIA) and the mean reciprocal creatinine concentration measured in the subsequent five days. In 15 of 32 (47%) patients the negative correlation coefficient exceeded 0.7 (high susceptibility), whereas in 11 of 32 (34%) it was between 0.5 and 0.7 (medium susceptibility), and in only six of 32 (19%) was it less than 0.3 (low susceptibility). We found no consistent correlations between cyclosporine measurements and results of other renal-function tests or liver-function tests. This suggests that therapeutic doses of the drug are not hepatotoxic in most patients. There was, however, a significantly correlated decrease in the NSRIA/SRIA ratio and in serum bilirubin concentration with time post-operatively, reflecting improvement in hepatic function and clearance of the cyclosporine metabolites that are detected by NSRIA. Assays of cyclosporine in whole blood, but not in plasma, are of value in anticipating changes in renal function after heart and heart-lung transplantation.

scholarly journals Cost of Living with Parkinson’s Disease over 12 Months in Australia: A Prospective Cohort Study

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Shalika Bohingamu Mudiyanselage ◽  
Jennifer J. Watts ◽  
Julie Abimanyi-Ochom ◽  
Lisa Lane ◽  
Anna T. Murphy ◽  
...  
Keyword(s):  
Cohort Study ◽  
Health System ◽  
Prospective Cohort Study ◽  
Resource Use ◽  
Prospective Cohort ◽  
Annual Cost ◽  
Severe Disease ◽  
Medicare Data ◽  
The Mean

Background. Parkinson disease (PD) is a costly chronic condition in terms of managing both motor and nonmotor symptoms. The burden of disease is high for individuals, caregivers, and the health system. The aim of this study is to estimate the annual cost of PD from the household, health system, and societal perspectives. Methods. A prospective cohort study of newly referred people with PD to a specialist PD clinic in Melbourne, Australia. Participants completed baseline and monthly health resource use questionnaires and Medicare data were collected over 12 months. Results. 87 patients completed the 12-month follow-up assessments. The mean annual cost per person to the health care system was $32,556 AUD. The burden to society was an additional $45,000 per annum per person with PD. The largest component of health system costs were for hospitalisation (69% of total costs). The costs for people with moderate to severe disease were almost 4 times those with mild PD ($63,569 versus $17,537 p<0.001). Conclusion. PD is associated with significant costs to individuals and to society. Costs escalated with disease severity suggesting that the burden to society is likely to grow with the increasing disease prevalence that is associated with population ageing.

Sign in / Sign up

Export Citation Format

Share Document