The independent association of preoperative serum albumin on the functional maturation of radiocephalic arteriovenous fistulae

2017 ◽  
Vol 18 (2) ◽  
pp. 148-152 ◽  
Author(s):  
Ali Kordzadeh ◽  
Evripidis Tokidis ◽  
Alan Askari ◽  
Mekhola Hoff ◽  
Yiannis Panayiotopoulos
Keyword(s):  
Null Hypothesis ◽  
Causal Link ◽  
Multivariate Logistic Regression Model ◽  
Arteriovenous Fistulae ◽  
Functional Maturation ◽  
Preoperative Serum ◽  
Chi Squared ◽  
Independent Association ◽  
Independent Marker ◽  
Preoperative Albumin

Purpose The aim of this study is to test the null hypothesis that preoperative albumin along with other preoperative confounders have no impact on the functional maturation of radiocephalic arteriovenous fistulae (RCAVF). Methods A retrospective cohort study of n = 195 individuals undergoing RCAVF formation from July 2013 to December 2015 was conducted. The null hypothesis was assessed through chi squared test. Independent association of each variable was evaluated through univariate and multivariate logistic regression model. Pearson's correlation test was also performed between scale variables to establish their causal link. Results Preoperative hypoalbuminaemic group of individuals demonstrated significant failure of maturation (49.3% vs. 27.2%, p = 0.002). At multivariate analysis, hypoalbuminemia remained an independent marker of fistula failure (OR 0.40, 95% CI 0.21-0.76, p = 0.004) and demonstrated a weak but a positive correlation at the endpoint of maturation (R = 0.223, p = 0.002). Conclusions Preoperative hypoalbuminemia (<35 mg/dL) is independently associated with 40% reduction in the functional maturation of RCAVF. Stratification of this readily available biomarker prior to RCAVF formation may require consideration subjected to further research.

The Distribution of later Bronze Age Metalwork from Lincolnshire

1971 ◽  
Vol 37 (1) ◽  
pp. 96-111 ◽  
Author(s):  
P. J. Davey
Keyword(s):  
Bronze Age ◽  
Null Hypothesis ◽  
Local Variation ◽  
Chi Squared ◽  
Image Position ◽  
Physiographic Regions ◽  
Random Scatter

A number of distinctive physiographic regions fall wholely or partly within the county of Lincolnshire: the limestone and chalk uplands of the Lincoln Edge and the Wolds, the valleys of the Trent, Ancholme and Witham, and the low lying areas of the Isle of Axholme, the Fens and the Marsh (fig. 1). The scatter of finds of Later Bronze Age metalwork shows considerable local variation (fig. 2).These differences in distribution can be analysed statistically using the Chi Squared test (Gregory, 1963, 151–66). A comparison is made between the observed distribution of objects (o), and the pattern expected if the distribution was the product of random factors alone (e). A null hypothesis is tested by applying the formula:.The probability that the null hypothesis is true can then be shown graphically (Lindley and Miller, 1953). A high reading (e.g., more than 95 per cent) would indicate that the observed distribution was consonant with a random scatter, while a low reading (e.g. less than 5 per cent) would suggest that some factor other than chance governed the distribution.

Venous thromboembolism (VTE) risk in patients with localized urinary tract tumors (UTT).

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 422-422 ◽  
Author(s):  
Jorge Ramos ◽  
Yu-Ning Wong ◽  
Simon J. Crabb ◽  
Guenter Niegisch ◽  
Joaquim Bellmunt ◽  
...  
Keyword(s):  
Risk Factors ◽  
Renal Dysfunction ◽  
Univariate Analysis ◽  
Multivariate Logistic Regression Model ◽  
Cvd Risk Factors ◽  
Cvd Risk ◽  
Related Factors ◽  
Metastatic Setting ◽  
Chi Squared ◽  
Localized Disease

422 Background: VTE is common in cancer patients, but there is limited data in patients with UTT. We previously demonstrated that non-urothelial histology, cardiovascular disease (CVD) or CVD risk factors or renal dysfunction increased VTE risk in metastatic UTT. In this study, we assessed the frequency and risk factors for VTE in localized disease. Methods: Data was collected via an electronic data capture platform from 29 centers. Patients diagnosed with < cT2, > N1, or M1 disease at diagnosis were excluded. Patients without a date of diagnosis, last follow up, or VTE data were excluded. Cumulative, unadjusted VTE incidence was calculated from time of diagnosis, excluding VTEs diagnosed in the metastatic setting. Chi-squared analyses were used to assess differences in VTE rates for various patient, therapy, and tumor-related factors. Significant covariates were incorporated into a multivariate, logistic regression model. Results: 1131 patients were eligible for analysis. Perioperative chemotherapy was utilized in 46.9% (530/1131) of patients. 70.8% (801/1131) underwent definitive surgical intervention. There were 64 VTEs (cumulative incidence 5.7%). Treatment with chemotherapy (p = 0.609) or surgery (p = 0.886) did not increase VTE risk. In the univariate analysis, non-urothelial histology (p = 0.025), CVD or CVD risk factors (p = 0.004), renal dysfunction (p = 0.023), and radiation to the primary tumor (p = 0.048) were statistically significant factors. Multivariate analysis demonstrated that non-urothelial histology and CVD or CVD risk factors were associated with increased VTE risk (table). Conclusions: The VTE incidence of 5.7% in localized disease is lower than our previously reported rate in the metastatic setting (8.2%). Consistent with our findings in metastatic UTT, non-urothelial histology and CVD or CVD risk factors increase VTE risk in localized disease. Additional analyses to control for baseline demographics in patients treated with surgery and chemotherapy will be performed. [Table: see text]

scholarly journals Usefulness of Leukocyte Esterase Test Versus Rapid Strep Test for Diagnosis of Acute Strep Pharyngitis

2015 ◽  
Vol 2 ◽  
pp. 2333794X1559915 ◽  
Author(s):  
Kumara V. Nibhanipudi
Keyword(s):  
Null Hypothesis ◽  
Throat Swab ◽  
Test Strip ◽  
Rapid Diagnosis ◽  
Acute Pharyngitis ◽  
Chi Squared ◽  
Data Configuration ◽  
Group A ◽  
Urine Testing ◽  
Statistical Results

Objective: A study to compare the usage of throat swab testing for leukocyte esterase on a test strip(urine dip stick-multi stick) to rapid strep test for rapid diagnosis of Group A Beta hemolytic streptococci in cases of acute pharyngitis in children. Hypothesis: The testing of throat swab for leukocyte esterase on test strip currently used for urine testing may be used to detect throat infection and might be as useful as rapid strep. Methods: All patients who come with a complaint of sore throat and fever were examined clinically for erythema of pharynx, tonsils and also for any exudates. Informed consent was obtained from the parents and assent from the subjects. 3 swabs were taken from pharyngo-tonsillar region, testing for culture, rapid strep & Leukocyte Esterase. Results: Total number is 100. Cultures 9(+); for rapid strep== 84(-) and16 (+); For LE== 80(-) and 20(+) Statistics: From data configuration Rapid Strep versus LE test don’t seem to be a random (independent) assignment but extremely aligned. The Statistical results show rapid and LE show very agreeable results. Calculated Value of Chi Squared Exceeds Tabulated under 1 Degree Of Freedom (P<.0.0001) reject Null Hypothesis and Conclude Alternative Conclusions: Leukocyte esterase on throat swab is as useful as rapid strep test for rapid diagnosis of strep pharyngitis on test strip currently used for urine dip stick causing acute pharyngitis in children.

Power Anaysis of Independence Testing for Two-Way Contingency Tables Bigger than 2×2

2016 ◽  
Vol 63 (2) ◽  
pp. 191-210 ◽  
Author(s):  
Piotr Sulewski
Keyword(s):  
Monte Carlo ◽  
Statistical Analysis ◽  
Null Hypothesis ◽  
Contingency Tables ◽  
Critical Values ◽  
Simulation Methods ◽  
The Family ◽  
Chi Squared ◽  
Independence Testing

In the statistical literature there are many test measures to study the independence features in the two-way contingency tables. For statistical analysis, the family of six so-called “chi-squared statistic” was selected – including Pearson’s χ2 statistics – and the proposal of the author in the form of modu-lar statistics. In order to free themselves from the limitations of the applicability of the “chi-squared statisti c”, critical values for all analyzed statistics were determined by simulation methods of Monte Carlo. In order to compare the tests, the measure of untruthfulness of H0was proposed and calculated the power of the tests which is the ability of two-way contingency tables to reject null hypothesis which says that between features X and Y there is no relation.

Algorithmic Salvage Techniques in Non-Maturing Radiocephalic Arteriovenous Fistulae with Their Long-Term Patency

2017 ◽  
Vol 18 (5) ◽  
pp. 443-449 ◽  
Author(s):  
Ali Kordzadeh ◽  
Yiannis P. Panayiotopolous
Keyword(s):  
Minimally Invasive ◽  
Primary Patency ◽  
Minimally Invasive Procedures ◽  
Invasive Procedures ◽  
Arteriovenous Fistulae ◽  
Functional Maturation ◽  
Vein Diameter

Introduction The aim of this study is to examine the role of five different operative salvage techniques with their long-term primary patency (PP) in an algorithmic manner in gaining primary functional maturation (FM) in radio cephalic arteriovenous fistulae (RCAVF) formation following their impairment. Methods A prospective consecutive data collection on 195 patients undergoing only autogenous RCAVF formation from July 2013 to December 2015 was conducted. Each non-maturing fistula was then exposed to a salvage technique by an algorithmic methodology and their FM and PP was prospectively recorded. Results Forty-two patients were exposed to five different salvages techniques, with a median age of 67 years (IQR, 27-90), cephalic vein diameter of 2 mm (IQR, 1.5-4 mm) and radial artery diameter of 1.8 mm (IQR, 1.2-2.1 mm), demonstrated 63.1% FM and cumulative primary patency of 15.2 months (95% CI, 12.5-17.9) over a 21-month follow-up period. Conclusions Operative salvage techniques play an important role in achieving assisted functional maturation and long-term patency in RCAVF as an alternative and/or in conjunction with other minimally invasive procedures. These procedures can maximize access outcome, minimize bridging procedures, decrease complications and optimize patient anatomical resources for longer access provisions in an era of aging population.

Balloon-assisted maturation of autogenous arteriovenous fistulae: A randomized controlled prospective study

Vascular ◽  
2020 ◽  
pp. 170853812097987
Author(s):  
Mohammed Elkassaby ◽  
Nashaat Elsaadany ◽  
Khaled Mowaphy ◽  
Mosaad Soliman
Keyword(s):  
Controlled Study ◽  
Complication Rates ◽  
Arteriovenous Fistulae ◽  
Early Maturation ◽  
Randomized Controlled ◽  
Functional Maturation ◽  
Increased Risk ◽  
Group A ◽  
Group B

Background Current guidelines recommend referral of patient with renal failure for access creation 6 months before planned dialysis. There is a growing cohort of patients that require long-term hemodialysis without adequate preparation. Temporary dialysis catheters and rapid access arteriovenous grafts (AVG) are far from being an ideal solution in this scenario. In an effort to expedite maturation of autogenous arteriovenous fistulae (AVF), balloon-assisted maturation (BAM) was advised by some authors. This technique still lacks the support of high-level evidence studies. We investigated the ability of intra-operative BAM to induce early functional maturation of AVFs. Methods This is a prospective randomized controlled study conducted in a tertiary referral center, with a catchment area of more than 15 million population. Cases were divided into two groups; Group (A), where BAM technique was performed, while in the control group (B), the standard technique was used (NO BAM) for creation of AVFs. Results Between June 2017 and May 2019, 300 cases were recruited from a total of 648 primary AVF creation instances. Patients’ age ranged from 19 to 89 (mean 51.17 ±SD 15.5) years. Group A (BAM) included 52.3% ( n = 157) AVFs, while Group B included 47.7% ( n = 143) AVFs. The average maturation time was 3.7 weeks (SD ± 1.3, 95% CI 3.55–3.95) and 5.91 weeks (SD ± 2.2, 95% CI 5.55–6.26) for both groups, respectively ( p = 0.0001). 78.3% of the AVFs that underwent BAM showed early maturation within 2–4 weeks vs 32.2% only in the NO BAM group ( p = 0.002). Successful functional maturation was higher among cases of the BAM group (93%), compared to the NO BAM group (77%) ( p = 0.001). Complication rates were 9.6% and 4.9% in the two groups, respectively ( p = 0.042). Conclusion BAM can play a pivotal role in helping the dialysis society meet the goals of the Fistula First Initiative, keeping in mind that this comes with an increased risk of complications. BAM should be considered only when unplanned early access to long-term dialysis is required.

scholarly journals Preoperative High-Protein Diet Can Improve The Serum Albumin Levels of Patients Undergoing Total Knee Arthroplasty

2020 ◽  
Author(s):  
Hong Xu ◽  
Li Liu ◽  
Jinwei Xie ◽  
Duan Wang ◽  
Zeyu Huang ◽  
...  
Keyword(s):  
Serum Albumin ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Preoperative Serum ◽  
Total Knee ◽  
The Relationship ◽  
Preoperative Albumin

Abstract Background: Preoperative hypoproteinemia are risk factors for complications in patients undergoing total knee arthroplasty (TKA). However, the relationship between preoperative albumin levels and postoperative use of albumin is unclear, as are the effects of a high-protein diet on preoperative serum albumin levels for these patients. Methods: We retrospectively enrolled 660 patients who underwent primary TKA from January to December 2019, of whom 97 received postoperative albumin and 563 did not. Logistic and restrictive cubic spline regression analyses were used to explore the relationship between preoperative serum albumin levels and postoperative albumin use. Additionally, 88 patients undergoing primary TKA were educated to follow a high-protein diet during the preoperative waiting period from January to July 2020. From these 88 patients, data from laboratory tests on the day of the outpatient visit and admission were collected and compared to evaluate the effect of high-protein diet on preoperative serum albumin levels. Results: Higher preoperative serum albumin levels were negatively associated with risk of postoperative albumin use (relative risk 0.725, 95% confidence interval 0.666-0.789), and the risk of needing postoperative albumin decreased with increasing preoperative albumin level with a negative dose-response relationship (P overall < 0.001; P nonlinear = 0.186). After an average of 39.05±22.78 days on a high-protein diet, the albumin levels on admission (46.04±2.49 g/L) were significantly higher than on outpatient (42.79±4.09) g/L), while the biomarkers of liver and kidney function and lipid metabolism did not differ significantly between the two time points. Conclusions: Preoperative albumin levels were highly associated with postoperative albumin use, showing an obvious dose-response relationship. Preoperative high-protein diet could improve the albumin levels in patients undergoing TKA. Trial registration: The study was registered in the Chinese Clinical Trial Registry (registration no. ChiCTR2000034978) on July 26, 2020.

scholarly journals Dominance of Alpha and Iota variants in SARS-CoV-2 vaccine breakthrough infections in New York City

2021 ◽  
Author(s):  
Ralf Duerr ◽  
Dacia Dimartino ◽  
Christian Marier ◽  
Paul Zappile ◽  
Guiqing Wang ◽  
...  
Keyword(s):  
New York ◽  
New York City ◽  
Immune Evasion ◽  
Null Hypothesis ◽  
Immune Escape ◽  
Real Life ◽  
Receptor Binding Domain ◽  
Vaccine Type ◽  
Genomic Analyses ◽  
Chi Squared

The efficacy of COVID-19 mRNA vaccines is high, but breakthrough infections still occur. We compared the SARS-CoV-2 genomes of 67 breakthrough cases after full vaccination with BNT162b2 (Pfizer/BioNTech), mRNA-1273 (Moderna), or JNJ-78436735 (Janssen) to unvaccinated controls (February-April 2021) in metropolitan New York, including their phylogenetic relationship, distribution of variants, and full spike mutation profiles. Their median age was 45 years; seven required hospitalization and one died. Most breakthrough infections (54/67) occurred with B.1.1.7 (Alpha) or B.1.526 (Iota). Among the 7 hospitalized cases, 5 were infected with B.1.1.7, including 1 death. Both unmatched and matched statistical analyses considering age, sex, vaccine type, and study month as covariates supported the null hypothesis of equal variant distributions between vaccinated and unvaccinated in chi-squared and McNemar tests (p>0.1) highlighting a high vaccine efficacy against B.1.1.7 and B.1.526. There was no clear association among breakthroughs between type of vaccine received and variant. In the vaccinated group, spike mutations in the N-terminal domain and receptor-binding domain that have been associated with immune evasion were overrepresented. The evolving dynamic of SARS-Co-V2 variants requires broad genomic analyses of breakthrough infections to provide real-life information on immune escape mediated by circulating variants and their spike mutations.

Tests’ power for independence in the two-way contingency table

2016 ◽  
Vol 61 (8) ◽  
pp. 1-17
Author(s):  
Piotr Sulewski
Keyword(s):  
Monte Carlo ◽  
Statistical Analysis ◽  
Monte Carlo Methods ◽  
Null Hypothesis ◽  
Contingency Table ◽  
Contingency Tables ◽  
Critical Values ◽  
The Family ◽  
Chi Squared ◽  
Simulation Monte Carlo

In the statistical literature there are many test measures to study the independence of features in the two-way contingency tables. For statistical analysis, the family of six so-called ”chi-squared statistic” was selected — including Pearson’s X² statistics — and the proposal of the author in the form of modular statistics. In order to free themselves from the limitations of the applicability of the ”chi-squared statistic”, critical values for all analyzed statistics were determined by simulation Monte Carlo methods. In order to compare the tests, the measure of untruthfulness of H₀ was proposed and calculated the power of the tests which is the ability of two-way contingency tables to reject null hypothesis which says that between features X and Y there is no relation.

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