110. Determination of Upperbound Failure Rate by Graphic Confidence Interval Estimate

2001 ◽  
Author(s):  
K. Kim
Keyword(s):  
Confidence Interval ◽  
Failure Rate ◽  
Interval Estimate

scholarly journals Alterations of Left Ventricular Hypertrophy in and Survival of Patients Receiving Hemodialysis: Follow-up of an Interventional Study

2001 ◽  
Vol 12 (12) ◽  
pp. 2759-2767 ◽  
Author(s):  
Gérard M. London ◽  
Bruno Pannier ◽  
Alain P. Guerin ◽  
Jacques Blacher ◽  
Sylvain J. Marchais ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Left Ventricular ◽  
Independent Effect ◽  
Lv Mass ◽  
History Of ◽  
Cv Disease ◽  
Stage Renal Disease ◽  
End Stage

ABSTRACT. Left ventricular (LV) hypertrophy (LVH) is a risk factor for mortality in patients with end-stage renal disease (ESRD). Whether the attenuation of LVH has a positive effect on survival of patients with ESRD has not been documented. The aim of this study was to determine the effect of parallel treatment of hypertension and anemia on LV mass (LVM) and to determine the effect of LVM changes on survival. A cohort of 153 patients receiving hemodialysis was studied. The duration of follow-up was 54 ± 37 mo. All patients had echocardiographic determination of LV dimensions and LVM at baseline and regular intervals until the end of the follow-up period. During the study, BP decreased from (mean ± SD) 169.4 ± 29.7/90.2 ± 15.6 to 146.7 ± 29/78 ± 14.1 mmHg (P< 0.001), and hemoglobin increased from 8.65 ± 1.65 to 10.5 ± 1.45 g/dl (P< 0.001). The LV end-diastolic diameter and mean wall thickness decreased from 56.6 ± 6.5 to 54.8 ± 6.5 mm (P< 0.001), and from 10.4 ± 1.6 to 10.2 ± 1.6 mm (P< 0.05), respectively. The LVM decreased from 290 ± 80 to 264 ± 86 g (P< 0.01). Fifty-eight deaths occurred, 38 attributed to cardiovascular (CV) disease and 20 attributed to non-CV causes. According to Cox analyses after adjustment for age, gender, diabetes, history of CV disease, and all nonspecific CV risk factors, LVM regression positively affected the survival. The hazard risk ratio associated with a 10% LVM decrease was 0.78 (95% confidence interval, 0.63 to 0.92) for all-causes mortality and 0.72 (95% confidence interval, 0.51 to 0.90) for mortality due to CV disease. These results show that a partial LVH regression in patients with ESRD had a favorable and independent effect on patients’ all-cause and CV survival.

Markov Chain Monte Carlo-Based Estimation of Stress–Strength Reliability Parameter for Generalized Linear Failure Rate Distributions

2021 ◽  
pp. 2150031
Author(s):  
F. Shahsanaei ◽  
A. Daneshkhah
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Failure Rate ◽  
Interval Estimate ◽  
Reliability Parameter ◽  
Bayes Estimates ◽  
Squared Error ◽  
Classical Inference ◽  
Strength Models

This paper provides Bayesian and classical inference of Stress–Strength reliability parameter, [Formula: see text], where both [Formula: see text] and [Formula: see text] are independently distributed as 3-parameter generalized linear failure rate (GLFR) random variables with different parameters. Due to importance of stress–strength models in various fields of engineering, we here address the maximum likelihood estimator (MLE) of [Formula: see text] and the corresponding interval estimate using some efficient numerical methods. The Bayes estimates of [Formula: see text] are derived, considering squared error loss functions. Because the Bayes estimates could not be expressed in closed forms, we employ a Markov Chain Monte Carlo procedure to calculate approximate Bayes estimates. To evaluate the performances of different estimators, extensive simulations are implemented and also real datasets are analyzed.

Method for Constructing a Confidence Interval for the Variance of a Random Variable

Vestnik NSUEM ◽  
2021 ◽  
pp. 146-155
Author(s):  
A. V. Ganicheva ◽  
A. V. Ganichev
Keyword(s):  
Probability Distribution ◽  
Confidence Interval ◽  
Random Variable ◽  
New Method ◽  
Interval Estimate ◽  
Normal Law

The problem of reducing the number of observations for constructing a confidence interval of variance with a given degree of accuracy and reliability is considered. The new method of constructing an interval estimate of variance developed in the article is formulated by three statements and justified by four proven theorems. Formulas for calculating the required number of observations depending on the accuracy and reliability of the estimate are derived. The results of the calculations are presented in the table and shown in the diagram. The universality and effectiveness of this method is shown. The universality of the method lies in the fact that it is applicable to any laws of probability distribution, and not only for the normal law. The effectiveness of the developed method is justified by comparing its performance with other known methods.

scholarly journals Detection of Specific Antinuclear Reactivities in Patients with Negative Anti-nuclear Antibody Immunofluorescence Screening Tests

2002 ◽  
Vol 48 (12) ◽  
pp. 2171-2176 ◽  
Author(s):  
Ilse EA Hoffman ◽  
Isabelle Peene ◽  
Eric M Veys ◽  
Filip De Keyser
Keyword(s):  
Connective Tissue ◽  
Confidence Interval ◽  
Connective Tissue Disease ◽  
Indirect Immunofluorescence ◽  
Connective Tissue Diseases ◽  
Clinical Suspicion ◽  
Screening Tests ◽  
Strongly Correlated ◽  
Nuclear Antigens

Abstract Background: For detection of anti-nuclear antibodies (ANAs) and antibodies to extractable nuclear antigens (ENAs), samples frequently are screened with indirect immunofluorescence (IIF); further determination of anti-ENA antibodies is performed only when the result is positive. However, because anti-ENA reactivities are found in samples with low fluorescence intensities, we determined anti-ENA antibodies in samples with negative IIF and thus calculated the sensitivity of IIF for specific ANAs. Methods: We collected 494 samples consecutively referred by rheumatologists for routine ANA testing. IIF on HEp-2 and HEp-2000 (HEp-2 cells transfected with Ro60 cDNA) and line immunoassay (LIA) for the detection of specific ANAs were performed on all samples. Results: Fluorescence intensities and patterns on HEp-2 were strongly correlated with those on HEp-2000 [Spearman ρ = 0.852 (P &lt;0.001) and 0.838 (P &lt;0.001), respectively]. Sixty-eight of 494 samples were positive on LIA, of which only 72% (confidence interval, 68–76%) were detected with HEp-2 and 75% (confidence interval, 70–78%) with HEp-2000. Of 291 samples negative on both substrates, 12 were positive on LIA. Connective tissue diseases were diagnosed in four of these patients and suspected in at least three others. Conclusion: The HEp-2 and HEp-2000 substrates perform comparably for fluorescence intensities and patterns and for detecting specific ANAs, but some patients with negative IIF show reactivity on LIA. We recommend testing for fine reactivities, regardless of the IIF result, when the clinical suspicion for rheumatic connective tissue disease is high.

Microbiological Determination of Neomycin in Feeds: Collaborative Study

1989 ◽  
Vol 72 (2) ◽  
pp. 237-241
Author(s):  
Gerald L Stahl ◽  
D Dal Kratzer ◽  
Charles W Kasson
Keyword(s):  
Statistical Analysis ◽  
Confidence Interval ◽  
Salt Concentration ◽  
Agar Medium ◽  
Collaborative Study ◽  
Tris Buffer ◽  
Official Method ◽  
The Mean ◽  
Swine Feed

Abstract A modification of the AOAC microbiological determination of neomycin in feeds was collaboratively studied by 12 laboratories. The official method was modified by substituting a constant salt concentration diluent for the feed extract diluent, preparing the agar medium in tris buffer, and performing the test with a monolayer plating system. Each laboratory performed single assays on 8 samples in a randomized sequence. The samples included duplicates of a cattle and swine feed at 2 different marketed concentrations. The mean recovery across all laboratories was 110.7% of theory with a range of means of 69.4-128.6 across the 12 laboratories. The results of one laboratory and 2 additional values from different laboratories were deemed outliers and excluded from statistical analysis. The statistical analysis gave a confidence interval of ± 26% for individual assays.

scholarly journals Clinic-morphological diagnosis of Barrett’s esophagus

2018 ◽  
Vol 85 (7) ◽  
pp. 9-12 ◽  
Author(s):  
O. G. Кuryk ◽  
М. Yu. Коlomoiets ◽  
V. О. Yakovenko ◽  
Т. V. Теreshchenko Т. V. Теreshchenko ◽  
R. P. Тkachenko
Keyword(s):  
Confidence Interval ◽  
Barrett’S Esophagus ◽  
Barrett's Esophagus ◽  
Objective Criterion ◽  
Disease Prognosis ◽  
Morphological Diagnosis ◽  
Endoscopic Investigation ◽  
Objective Determination ◽  
Selection Of

Objective. Determination of efficacy of morphological diagnosis of the Barrett’s esophagus (BE). Маterials and methods. Diagnosis of BE in accordance to data obtained during screening endoscopic investigation with biopsy and morphological verification in 2014 - 2016 yrs, basing on Medical Centre «University Clinic «Оberig», Kyiv, was analyzed. Results. BE was diagnosed in 841 (36.8%) patients (95% of confidence interval (CІ) 36.02 – 39.76) among 2405 patients, in whom esophagogastroscopy was conducted. Histologically cardiac metaplasia was revealed in 48 (5.71%) patients, fundic - in 136 (16.19%), intestinal specialized - in 625 (72.28%), and the mixed - in 32 (3.81%) patients. Dysplasia of high and low grades was diagnosed in 32 (3.81%) (95% CІ 2.04 – 4.62), including: in 24 (75.0%) - low, and in 8 (25.0%) – high. Аdenocarcinoma was revealed in 4 (0.47%) patients (95% CІ 0.20 – 1.36). Conclusion. Мorphological verdict constitutes the main and objective criterion for the BE verification, what is important for selection of the treatment tactics and certainly help to determine the disease prognosis.

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