scholarly journals Fixed-width confidence interval for a lognormal mean

2002 ◽  
Vol 29 (3) ◽  
pp. 143-153 ◽  
Author(s):  
Makoto Aoshima ◽  
Zakkula Govindarajulu
Keyword(s):  
Confidence Interval ◽  
Asymptotic Properties ◽  
Sequential Procedure ◽  
Two Stage ◽  
Accelerated Sequential Procedure ◽  
Width Confidence Interval

We consider the problem of constructing a fixed-width confidence interval for a lognormal mean. We give a Birnbaum and Healy type two-stage procedure to construct such a confidence interval. We discuss some asymptotic properties of the procedure. A three-stage procedure and an accelerated sequential procedure are also given for the comparison of efficiency among these three multistage methodologies.

scholarly journals Multistage Estimation of the Rayleigh Distribution Variance

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2084
Author(s):  
Ali Yousef ◽  
Ayman A. Amin ◽  
Emad E. Hassan ◽  
Hosny I. Hamdy
Keyword(s):  
Confidence Interval ◽  
Sample Size ◽  
Interval Estimation ◽  
Sequential Estimation ◽  
Rayleigh Distribution ◽  
Point Estimation ◽  
Asymptotic Results ◽  
Squared Error Loss Function ◽  
Estimation Problems ◽  
Width Confidence Interval

In this paper we discuss the multistage sequential estimation of the variance of the Rayleigh distribution using the three-stage procedure that was presented by Hall (Ann. Stat. 9(6):1229–1238, 1981). Since the Rayleigh distribution variance is a linear function of the distribution scale parameter’s square, it suffices to estimate the Rayleigh distribution’s scale parameter’s square. We tackle two estimation problems: first, the minimum risk point estimation problem under a squared-error loss function plus linear sampling cost, and the second is a fixed-width confidence interval estimation, using a unified optimal stopping rule. Such an estimation cannot be performed using fixed-width classical procedures due to the non-existence of a fixed sample size that simultaneously achieves both estimation problems. We find all the asymptotic results that enhanced finding the three-stage regret as well as the three-stage fixed-width confidence interval for the desired parameter. The procedure attains asymptotic second-order efficiency and asymptotic consistency. A series of Monte Carlo simulations were conducted to study the procedure’s performance as the optimal sample size increases. We found that the simulation results agree with the asymptotic results.

Fixed Length Interval Estimation of the Location Parameter of a Pareto Distribution

1986 ◽  
Vol 35 (1-2) ◽  
pp. 67-76 ◽  
Author(s):  
Malay Ghosh ◽  
Dennis Wackerly
Keyword(s):  
Confidence Interval ◽  
Shape Parameter ◽  
Pareto Distribution ◽  
Interval Estimation ◽  
Location Parameter ◽  
Fixed Length ◽  
Asymptotically Efficient ◽  
Width Confidence Interval

A sequential fixed-width confidence interval for the location parameter of a Pareto distribution with unknown shape parameter is developed. The procedure Is shown to be asymptotically consistent and asymptotically efficient in the sense of Chow and Robbins (1965).

P4714Individual patient data meta-analysis comparing general anesthesia and deep sedation on safety and length of intensive care unit stay in patients undergoing percutaneous mitral valve repair

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Jobs ◽  
S De Waha-Thiele ◽  
J Ledwoch ◽  
H Sievert ◽  
T Rassaf ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Confidence Interval ◽  
Deep Sedation ◽  
Meta Analysis ◽  
Valve Repair ◽  
Two Stage ◽  
Intensive Care Stay ◽  
Safety Endpoint ◽  
Procedural Success

Abstract Background Percutaneous edge-to-edge mitral valve repair (PMVR) has emerged as a treatment option for patients with severe mitral regurgitation not considered suitable candidates for surgery. The procedure can be performed in general anesthesia (GA) or deep sedation (DS) without mechanical ventilation. However, debate remains about the optimal approach. Purpose To compare the impact of the anesthetic method on efficacy, safety, and length of intensive care stay. Methods We identified studies comparing GA versus DS in patients undergoing PMVR by searching PubMed and CENTRAL. We included studies for which investigators agreed to provide individual patient data. Analyzed outcomes were a composite safety endpoint comprising all-cause death, stroke, pneumonia, and major to life-threating bleeding as well as length of intensive care unit stay. We performed an one-stage and two-stage meta-analysis on each outcome after multiple imputation of missing data. For two-stage meta-analysis, between-study heterogeneity was estimated according to Paule-Mandel and confidence intervals were derived using the method proposed by Hartung and Knapp. Results We included five observational studies (n=647 patients). Procedural success was achieved in 618 of 647 (95.5%) patients. The composite safety endpoint occurred in 92 of 647 (14.2%) patients with no difference between patients treated with GA or DS. In this regard, risk ratio was 0.78 (95% confidence interval, 0.53 to 1.14; P=0.20) following the one-stage approach and 0.73 (95% confidence interval, 0.30 to 1.80; P=0.39) following the two-stage approach. Length of intensive care stay was longer after GA as compared to DS (adjusted mixed linear regression model, 1.94 days, 95% confidence interval, 1.29 to 2.59 days, P<0.001; random effects model pooling study-specific estimates from adjusted linear models 1.40 days, 95% confidence interval, 0.54 to 2.22 days, P=0.0104). Conclusion Both, DS and GA offer good procedural success rates and a similar safety profile. However, length of intensive care stay is shorter after DS.

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