scholarly journals SILR: A New Exact Test for Demonstrating That an Effect Exists in Binary Trials

2021 ◽  
Author(s):  
Zhengze Zhou ◽  
Richard B. Darlington
Keyword(s):  
Power Analysis ◽  
Confidence Limits ◽  
Success Rates ◽  
Significance Level ◽  
Exact Test ◽  
Hit Rate ◽  
R Program ◽  
Higher Power ◽  
Binary Trials ◽  
Null Value

Suppose N experimental participants each undergo t binary trials, and you want to show that at least some of the participants have higher success rates than would be expected if the true success rate for all participants on all trials were the same known value pnull. Under broad circumstances, a new test called SILR has substantially higher power than six other tests that might be used for this purpose. In one example, SILR yielded a significance level of 0.0032 while the other six tests all yielded values above 0.05. In one power analysis, SILR’s power exceeded that of the standard binomial test, applied to the results of all trials for all participants, even when the sample size for SILR was less than 30% that for the binomial.We provide a free R program for SILR. It can also find confidence limits on the number of experimental participants whose true hit rate exceeds the null value, and on the highest and lowest true hit rates of any participants. SILR does not show conclusively that any particular participant’s true hit rate differs significantly from the null rate. If such tests are desired, that can be done with Bonferroni-corrected binomial tests on individual participants. But SILR often has much higher power than these tests.

Vein cannulation success rates by German paramedics: a single-centre study

2021 ◽  
Vol 11 (2) ◽  
pp. 35-39
Author(s):  
Paulina Naklicka ◽  
Luis Möckel ◽  
Thomas Hofmann
Keyword(s):  
Vascular Access ◽  
Night Shift ◽  
Federal State ◽  
Success Rates ◽  
Single Centre ◽  
Exact Test ◽  
Factors Associated ◽  
Risk Of Failure ◽  
Single Centre Study ◽  
Cannulation Success

Introduction: Gaining intravenous (IV) access is vulnerable to errors and failure, and this study analysed IV procedures by paramedics in the federal state of Hesse in Germany to examine these. Methods: This was a single-centre, observational, pilot study survey on gaining vascular access. As well as identifying the success and failure rate of IV attempts, factors associated with a higher risk of failure were analysed using logistic regression, Χ2 or Fisher's exact test. Results: A total of 207 vascular access attempts were included in the analysis, of which 90.34% were successful. Significantly associated with higher risk of failure were patients' age (OR 1.05; 95% (CI 1.02–1.10); p=0.041), or when two (OR 3.94; 95% CI (2.39–6.20); p≤0.001) or more than three attempts (OR: 3.26 [95% CI: 1.35; 5.17]; p=0.003) were needed rather than one. In contrast, risk of failure was significantly lower when patients indicate a good (OR 0.02; 95% CI (0.00–0.15); p≤0.001) or moderate (OR 0.04 (95% CI 0.01–0.17); p≤0.001) vein status compared to a bad vein status. Failure rates were higher when paramedics were working a night shift (OR 0.06; 95% CI (0.00–0.98); p=0.005) rather then during the day. Conclusion: A proportion of IV access attempts by paramedics are unsuccessful and, if paramedics are to provide invasive interventions, non-IV options for drug administration should be available.

High Success Rate of Prehospital and En Route Cricothyroidotomy Performed in the Israel Defense Forces: 20 Years of Experience

2021 ◽  
pp. 1-6
Author(s):  
Eran Beit Ner ◽  
Avishai M. Tsur ◽  
Roy Nadler ◽  
Elon Glassberg ◽  
Avi Benov ◽  
...  
Keyword(s):  
Success Rate ◽  
Body Part ◽  
Salvage Procedure ◽  
Care Providers ◽  
Success Rates ◽  
Exact Test ◽  
Medical Teams ◽  
Israel Defense Forces ◽  
Different Levels ◽  
Overall Mortality

Abstract Introduction: Securing the airway is a crucial stage of trauma care. Cricothyroidotomy (CRIC) is often addressed as a salvage procedure in complicated cases or following a failed endotracheal intubation (ETI). Nevertheless, it is a very important skill in prehospital settings, such as on the battlefield. Hypothesis/Problem: This study aimed to review the Israel Defense Forces (IDF) experience with CRIC over the past two decades. Methods: The IDF Trauma Registry (IDF-TR) holds data on all trauma casualties (civilian and military) cared for by military medical teams since 1997. Data of all casualties treated by IDF from 1998 through 2018 were extracted and analyzed to identify all patients who underwent CRIC procedures. Variables describing the incident scenario, patient’s characteristics, injury pattern, treatment, and outcome were extracted. The success rate of the procedure was described, and selected variables were further analyzed and compared using the Fisher’s-exact test to identify their effect on the success and failure rates. Odds Ratio (OR) was further calculated for the effect of different body part involvement on success and for the mortality after failed ETI. Results: One hundred fifty-three casualties on which a CRIC attempt was made were identified from the IDF-TR records. The overall success rate of CRIC was reported at 88%. In patients who underwent one or two attempts, the success rate was 86%. No difference was found across providers (physician versus paramedic). The CRIC success rates for casualties with and without head trauma were 80% and 92%, respectively (P = .06). Overall mortality was 33%. Conclusions: This study shows that CRIC is of merit in airway management as it has shown to have consistently high success rates throughout different levels of training, injuries, and previous attempts with ETI. Care providers should be encouraged to retain and develop this skill as part of their tool box.

scholarly journals Utilisation of CryoSat-2 SAR altimeter in operational ice charting

2016 ◽  
Vol 10 (1) ◽  
pp. 121-131 ◽  
Author(s):  
E. Rinne ◽  
M. Similä
Keyword(s):  
Synthetic Aperture Radar ◽  
Real Time ◽  
Training Data ◽  
Synthetic Aperture ◽  
First Year ◽  
Success Rates ◽  
Hit Rate ◽  
Snow Conditions ◽  
Simple Product ◽  
Barents And Kara Seas

Abstract. We present methods to utilise CryoSat-2 (CS-2) synthetic aperture radar (SAR) mode data in operational ice charting. We compare CS-2 data qualitatively to SAR mosaics over the Barents and Kara seas. Furthermore, we compare the CS-2 to archived operational ice charts. We present distributions of four CS-2 waveform parameters for different ice types as presented in the ice charts. We go on to present an automatic classification method for CS-2 data which, after training with operational ice charts, is capable of determining open ocean from ice with a hit rate of  >  90 %. The training data are dynamically updated every 5 days using the most recent 15 days of CS-2 data and operative ice charts. This helps the adaption of the classifier to the evolving ice/snow conditions throughout winter. The classifier is also capable of detecting three different ice classes (thin and thick first-year ice as well as old ice) with success rates good enough for the output to be usable to support operational ice charting. Finally, we present a near-real-time CS-2 product just plotting the waveform characteristics and conclude that even such a simple product is usable for some of the needs of ice charting.

scholarly journals Phlebitis associated with peripheral intravenous catheters in adults admitted to hospital in the Western Brazilian Amazon

2016 ◽  
Vol 50 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Sandra Maria Sampaio Enes ◽  
Simone Perufo Opitz ◽  
André Ricardo Maia da Costa de Faro ◽  
Mavilde de Luz Gonçalves Pedreira
Keyword(s):  
Intermittent Infusion ◽  
Brazilian Amazon ◽  
Fisher Exact Test ◽  
Intravenous Therapy ◽  
Chi Square ◽  
Significance Level ◽  
Exact Test ◽  
Dorsal Hand Vein ◽  
Mean Time ◽  
Intravenous Catheters

Abstract OBJECTIVE To identify the presence of phlebitis and the factors that influence the development of this complication in adult patients admitted to hospital in the western Brazilian Amazon. METHOD Exploratory study with a sample of 122 peripheral intravenous catheters inserted in 122 patients in a medical unit. Variables related to the patient and intravenous therapy were analyzed. For the analysis, we used chi-square tests of Pearson and Fisher exact test, with 5% significance level. RESULTS Complication was the main reason for catheter removal (67.2%), phlebitis was the most frequent complication (31.1%). The mean duration of intravenous therapy use was 8.81 days in continuous and intermittent infusion (61.5%), in 20G catheter (39.3%), inserted in the dorsal hand vein arc (36.9 %), with mean time of usage of 68.4 hours. The type of infusion (p=0.044) and the presence of chronic disease (p=0.005) and infection (p=0.007) affected the development of phlebitis. CONCLUSION There was a high frequency of phlebitis in the sample, being influenced by concomitant use of continuous and intermittent infusion of drugs and solutions, and more frequent in patients with chronic diseases and infection.

scholarly journals Avaliação das Variantes Genéticas dos Genes AMELX e ENAM na Cárie Dentária em Adolescentes

2021 ◽  
Vol 24 (5-esp.) ◽  
pp. 650-654
Author(s):  
Gabriela Paschoalini Romagni ◽  
Paula Marino Costa ◽  
Sandra Mara Maciel ◽  
Maria Paula Jacobucci ◽  
Regina Célia Poli-Frederico
Keyword(s):  
Genetic Component ◽  
World Health ◽  
Caries Experience ◽  
Nucleotide Polymorphisms ◽  
Chi Square ◽  
Single Nucleotide ◽  
Significance Level ◽  
Exact Test ◽  
Polymerase Chain ◽  
Health Organization

A doença cárie é considerada, atualmente, como biofilme sacarose dependente, entretanto, estudos recentes apontam que fatores genéticos também podem influenciar seu desenvolvimento. Variantes nos gene amelogenina (AMELX) e enamelina (ENAM), responsáveis pela formação do esmalte, têm sido propostas como potencialmente envolvidos na doença. O objetivo deste estudo foi avaliar se a ocorrência de cárie dentária em adolescentes está relacionado às variantes nos genes AMELX e ENAM. Para a avaliação da prevalência de cárie foi utilizado o índice de dentes cariados, perdidos e obturados (CPO-D), segundo critérios da Organização Mundial de Saúde. As amostras de DNA foram extraídas das células da mucosa oral. Para a análise dos polimorfismos de nucleotídeo único (SNPs) dos genes AMELX (rs17878486) e ENAM (rs7671281) foi utilizada  a técnica de amplificação de fragmentos de DNA pela reação em cadeia da polimerase foi realizada (PCR) em tempo real pelo sistema TaqMan (Applied Biosystems, Foster City, EUA). Para a análise estatística, foi utilizado o teste exato de Fisher e qui-quadrado com nível de significância de 5%. Apenas os fatores socioeconômicos influenciaram a experiência de cárie. Concluiu-se que o componente genético, na população deste estudo, não influenciou o desenvolvimento da cárie.   Palavras-chave: Polimorfismo genético. Adolescentes. Esmalte.   Abstract Caries disease is currently considered a sucrose-dependent biofilm, however recent studies indicate that a genetic component can also influence its development. Variants in the amelogenin (AMELX) and enamelin (ENAM) genes, responsible for the enamel formation, have been proposed as potentially involved in the disease. The purpose of this study was to evaluate whether the occurrence of dental caries in adolescents is related to variants in the AMELX and ENAM genes. To assess the caries prevalence, the index of decayed, missing and filled teeth (DMFT) were used, according to World Health Organization criteria. DNA samples were extracted from oral mucosa cells. For the analysis of single nucleotide polymorphisms (SNPs) of the AMELX (rs17878486) and ENAM (rs7671281) genes, the amplifying DNA fragments technique  by the polymerase chain reaction was performed (PCR) in real time by the TaqMan system (Applied Biosystems, Foster City, USA). For the statistical analysis, Fisher's exact test and chi-square were used with a 5% significance level. Only socioeconomic factors influenced the caries experience. It was concluded that the genetic component in the population of this study, did not influence the development of caries.   Keywords: Genetic polymorphism. Adolescents. Enamel.

scholarly journals Association between speech and dental occlusion changes in children with cleft lip and palate and time of primary plastic surgeries

Revista CEFAC ◽  
2021 ◽  
Vol 23 (4) ◽  
Author(s):  
Gabriela Ribeiro Schilling ◽  
Maria Cristina de Almeida Freitas Cardoso ◽  
Paulo Sérgio Gonçalves da Silva ◽  
Marcia Angélica Peter Maahs
Keyword(s):  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Cross Sectional Study ◽  
Dental Occlusion ◽  
Chi Square ◽  
Cross Sectional ◽  
Significance Level ◽  
Exact Test ◽  
Chi Square Test ◽  
Incisive Foramen

ABSTRACT Purpose: to describe the changes in speech and dental occlusion in children with cleft lip and palate and verify their association with each other and with the time of primary plastic surgeries. Methods: a cross-sectional study with collected data on the subjects’ identification, age at the time of primary surgeries, and clinical assessment of speech and dental occlusion. The chi-square test, Fisher's exact test, and t-test were used to verify the associations between the variables at the 5% significance level (p < 0.05). Results: the sample comprised 11 children aged 6 to 10 years, most of whom were males, self-reported white, with trans-incisive foramen cleft, predominantly on the left side. The mean age at lip repair surgery was 6 months, and 13 months at palatoplasty. Among the main dental occlusion changes, posterior and anterior crossbite stood out. All the subjects presented changed speech, with a prevalence of cases with dentoalveolar and palatine deformities, followed by passive and active changes. Subjects with anterior crossbite tended to have undergone primary lip repair surgery at a mean of four months earlier than the subjects without anterior crossbite. Conclusions: the associations between speech and dental occlusion changes, and between these and the time of primary plastic surgeries were not statistically significant. Even though it is known that early lip repair surgery is ideal to favor oral functions and aesthetics, the results revealed a tendency towards anterior crossbite, in these subjects.

scholarly journals Influence of apical foramen lateral opening and file size on cemental canal instrumentation

2012 ◽  
Vol 23 (2) ◽  
pp. 122-126 ◽  
Author(s):  
Ronaldo Araújo Souza ◽  
Yara T. Corrêa Silva Sousa ◽  
José Antônio Poli de Figueiredo ◽  
João da Costa Pinto Dantas ◽  
Suely Colombo ◽  
...  
Keyword(s):  
Root Apex ◽  
File Size ◽  
Significance Level ◽  
Exact Test ◽  
Cyanoacrylate Adhesive ◽  
Group 2 ◽  
Ethyl Cyanoacrylate ◽  
Student’S T ◽  
Cleaning And Disinfection ◽  
Selection Of

Since instrumentation of the apical foramen has been suggested for cleaning and disinfection of the cemental canal, selection of the file size and position of the apical foramen have challenging steps. This study analyzed the influence of apical foramen lateral opening and file size can exert on cemental canal instrumentation. Thirty-four human maxillary central incisors were divided in two groups: Group 1 (n=17), without flaring, and Group 2 (n=17), with flaring with LA Axxess burs. K-files of increasing diameters were progressively inserted into the canal until binding at the apical foramen was achieved and tips were visible and bonded with ethyl cyanoacrylate adhesive. Roots/files set were cross-sectioned 5 mm from the apex. Apices were examined by scanning electron microscopy at ×140 and digital images were captured. Data were analyzed statistically by Student’s t test and Fisher’s exact test at 5% significance level. SEM micrographs showed that 19 (56%) apical foramina emerged laterally to the root apex, whereas 15 (44%) coincided with it. Significantly more difficulty to reach the apical foramen was noted in Group 2. Results suggest that the larger the foraminal file size, the more difficult the apical foramen instrumentation may be in laterally emerged cemental canals.

Foodborne Snow Mountain Agent Gastroenteritis in a School Cafeteria

PEDIATRICS ◽  
1987 ◽  
Vol 79 (4) ◽  
pp. 559-563
Author(s):  
Charles Guest ◽  
Kenneth C. Spitalny ◽  
H. Paul Madore ◽  
Katherine Pray ◽  
Raphael Dolin ◽  
...  
Keyword(s):  
Relative Risk ◽  
Strong Association ◽  
Case Definition ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fisher Exact Test ◽  
Confidence Limits ◽  
Serum Samples ◽  
Exact Test ◽  
Relative Risks ◽  
The Mean

In 1984, an outbreak of gastroenteritis occurred at a school with 1,860 students in Brooklyn, NY. In a single-stage cluster sample of 375 students, 129 (34%) had illnesses that met our case definition of vomiting or diarrhea. The mean incubation period was 26 hours, and the mean illness duration was 24 hours. All case students had eaten in the cafeteria on at least one day between Nov 13 and 16, compared with 174/214 (81%) noncase students (P = 10-8, Fisher exact test). Foods implicated were french fries (relative risk 1.7, 95% confidence limits 1.4, 2.0) and hamburgers (relative risk 1.6, 95%, confidence limits 1.2, 2.1). Two cafeteria employees had served those foods while affected by diarrhea. By a recently developed blocking enzyme-linked immunosorbent assay, six of 11 (55%) case students showed fourfold antibody increases between acute-and convalescent-phase serum samples for Snow Mountain agent, a Norwalk-like virus, compared with one of ten (10%) noncase students (P = .04, Fisher exact test). We strongly suspect, but cannot document conclusively, that the Snow Mountain agent was spread to students on a vector of hot foods contaminated by ill food handlers. Implicated foods conferred low relative risks and could only have accounted for 74% of cases of illness. The strong association between cafeteria exposure and illness, therefore, suggests that additional modes of spread occurred.

scholarly journals Histology of the rectus abdominis muscle in rats subjected to cranial and caudal devascularization

2012 ◽  
Vol 27 (2) ◽  
pp. 162-167 ◽  
Author(s):  
Walder Costa ◽  
Alcino Lázaro da Silva ◽  
Gustavo Rocha Costa ◽  
Tarcizo Afonso Nunes
Keyword(s):  
Inflammatory Infiltrate ◽  
Microscopic Analysis ◽  
Rectus Abdominis ◽  
Rectus Abdominis Muscle ◽  
Significance Level ◽  
Exact Test ◽  
Delay Procedure ◽  
Histological Alterations ◽  
Group A ◽  
The Right

PURPOSE: To investigate the microscopic changes in the rectus abdominis muscle in rats subjected to five delay procedure. METHODS: 30 male holtzmann rats, weighting between 250 and 350 grams, were used. The animals were divided into five groups (n=6): A - cranial section of the right muscle; B - caudal section of the right muscle; C - craniocaudal section of the right muscle; D - cranial section reflecting the right muscle in the craniocaudal direction; E - caudal section reflecting the right muscle in the caudocranial direction. On the seventh day after surgery, a resection of the cranial and caudal fragments of the right and left muscles, respectively, was performed for microscopic analysis. Histological alterations were quantified and the right and left (control) muscle fragments compared. Fisher's exact test was used for statistical purposes with a significance level of 5%. RESULTS: The comparison between right and left muscles showed statistically significant differences in group A - inflammatory infiltrate in the cranial fragment (p=0.015); in group C - inflammatory infiltrate (p=0.000) and necrosis (p=0.015) in the caudal fragment; and in group E - edema in the caudal fragment (p=0.000). No significant alterations were noted in groups B and D. CONCLUSIONS: Irrigation exclusively through the perforating muscle vessels is inappropriate; irrigation exclusively through the cranial pedicle causes milder, insignificant histological alterations, when compared with irrigation exclusively through the caudal pedicle; irrigation exclusively through the caudal pedicle causes more pronounced, but still insignificant, histological alterations when compared with other forms of devascularization.

scholarly journals Tests of Independence for a $2 \times 2$ Contingency Table with Random Margins

2017 ◽  
Vol 6 (2) ◽  
pp. 106 ◽  
Author(s):  
Yuan Yu ◽  
Dhiman Bhadra ◽  
Balgobin Nandram
Keyword(s):  
Contingency Table ◽  
Bayes Factor ◽  
Small Sample ◽  
Ratio Test ◽  
Power Functions ◽  
Significance Level ◽  
Exact Test ◽  
Fisher's Exact Test ◽  
Cell Counts ◽  
Fisher’S Exact Test

Fisher's exact test is commonly used for testing the hypothesis of independence between the row and column variables in a $r \times c$ contingency table. It is a ``small-sample'' test since it is used when the sample size is not large enough for the Pearsonian chi-square test to be valid. Fisher's exact test conditions on both margins of a $2 \times 2$ table leading to a hypergeometric distribution of the cell counts under independence. Moreover, it is conservative in the sense that its actual significance level falls short of the nominal level. In this paper, we modify Fisher's exact test by lifting the restriction of fixed margins and allow the margins to be random. In doing so, we propose two new tests - a likelihood ratio test in a frequentist framework and a Bayes factor test in a Bayesian framework, both of which are based on a new multinomial distributional framework. We apply the three tests on data from the Worcester Heart Attack study and compare their power functions in assessing gender difference in the therapeutic management of patients with acute myocardial infarction (AMI).

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