Reliability of fetal–infant mortality rates in perinatal periods of risk (PPOR) analysis

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Vito Di Bona
Keyword(s):  
Infant Mortality ◽  
Standard Error ◽  
Infant Mortality Rate ◽  
Relative Standard Error ◽  
Statistical Reliability ◽  
Relative Standard ◽  
Vital Records ◽  
Large Populations ◽  
Perinatal Periods Of Risk ◽  
Interval Estimators

Abstract The Fetal–Infant mortality rate (FIMR) is the basic surveillance statistic in perinatal periods of risk (PPOR) analyses. This paper presents a model for the FIMR as the ratio of two Poisson random variables. From this model, expressions for estimators of variance, standard error, and relative standard error are developed. The coverage properties of interval estimators for the FIMR are investigated in a simulation study for both small and large populations and FIMR rates. Results from these studies are applied to a PPOR analysis of NC vital records. Results suggest that the sample size guidance provided in the literature to ensure statistical reliability is overly conservative and interval construction methodology should be selected based on population size.

scholarly journals Systematic Sampling for Estimating Harvest-Induced Changes of a Forest Stand

2009 ◽  
Vol 9 (1) ◽  
pp. 39-55
Author(s):  
Dennis Peque ◽  
Keyword(s):  
Sample Size ◽  
Standard Error ◽  
Basal Area ◽  
Systematic Sampling ◽  
Relative Standard Error ◽  
Stem Density ◽  
Relative Standard ◽  
The Individual ◽  
Induced Changes ◽  
Forest District

This study was conducted in Compartment 2012a in Bosinghausen Forest District in Germany covering an area of 5 hectared. Twenty two sampling plots were laid out in the field following systematic sampling design. Results showed that all estimates for all variables (e.g. tree heights, DBH, stem density, basal area and volume) under trees that were marked for cutting have higher relative standard error. This was due to higher dispersion of individual estimates in each plot. On the other hand, the simulation study shows that sampling efficiency can be acheived by increasing the sample size. When more samples are included, the relative standard error becomes low. From this study, it can be concluded that the variability of the estimates were affected by sample size and the variability of individual units in the population or the individual esitmates (in this case, estimates in each plot).

A Counting Method for Measuring the Volumes of Tissue Components in Microscopical Sections

1964 ◽  
Vol s3-105 (72) ◽  
pp. 503-517
Author(s):  
A. DOUGLAS HALLY
Keyword(s):  
Standard Error ◽  
Relative Volume ◽  
Square Lattice ◽  
Relative Standard Error ◽  
Consistent Estimate ◽  
Relative Area ◽  
Counting Method ◽  
Tissue Sections ◽  
Relative Standard ◽  
Random Sections

Several methods are available for estimating the relative volume of a tissue component from a study of tissue sections. These methods are all based on the fact that the mean relative area of a component in a series of random sections through a tissue is a consistent estimate of its relative volume in the whole tissue. Thus the problem is basically one of measuring area in a section, which can be done by the following simple counting method. The method consists of placing a regular pattern of points in the form of a square lattice upon the section image, and counting the number of points over the section N, and over the component n Relative area of component ≑n/N The method also measures absolute ares, and where d is the distance between adjacent points, absolute area of component ≑nd2 This capacity to measure absolute area means that the method is particularly suitable for determining a component which has a low relative volume. The accuracy of the method is influenced by several factors including the size of the grid mesh, and the relative area, shape, and spatial arrangment of the component. With reasonable care the error will not be larger than that of a truly randon system of points, as expressed by the following: relative standard error ≑√(1-p)/√n, where p is the relative area of the component, and the relative standard error (R.S.E.) is S.E./relative area of component. The method is equallyapplicable to either light or electron microscopy. A series of measurements on electron micrographs of rat cardiac muscle revealed a close agreement between the counting method and planimetry. The method is rapid, simple and accurate, and requres no complex apparatus.

Kinetic Method for the Determination of 2,4-Dinitrophenol

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
S. S. Mitic ◽  
V. V. Zivanovic ◽  
G. Z. Miletic ◽  
D. A. Kostic ◽  
I. D. Rasic
Keyword(s):  
Detection Limit ◽  
River Water ◽  
Standard Error ◽  
Kinetic Method ◽  
Relative Standard Error ◽  
Potassium Periodate ◽  
Experimental Conditions ◽  
Inhibiting Effect ◽  
Relative Standard

A kinetic method for the determination of dinitrophenol is proposed. The method is based on the inhibiting effect of 2,4-dinitrophenol on the Mn(II) catalysis of the oxidation of malachite green with potassium periodate. The reaction was monitored spectrophotometrically at 615 nm. Kinetic expressions for the reaction are postulated. The optimal experimental conditions for the determination of 2,4-dinitrophenol were established and 2,4-dinitrophenol was determined in concentrations from 0.092-0.92 mg . mL-1 with relative standard error of 5.9 %. Detection limit is 0.014 mg . mL-1. The selectivity of the method is appropriate. The method was applied for the determination of dinitrophenol in urine and river water.

scholarly journals GENERALIZED SYNTHETIC ESTIMATOR FOR DOMAIN MEAN IN TWO PHASE SAMPLING USING SINGLE AUXILIARY CHARACTER

2019 ◽  
pp. 139-151
Author(s):  
Ashutosh ◽  
B. B. Khare ◽  
S. Khare
Keyword(s):  
Simulation Study ◽  
Standard Error ◽  
Relative Bias ◽  
Relative Standard Error ◽  
Two Phase ◽  
Auxiliary Character ◽  
Relative Standard ◽  
Phase Sampling ◽  
Two Phase Sampling

In this paper, we have proposed a two phase sampling estimator for domain mean using auxiliary character with unknown X a domain mean. Also discussed properties of the proposed estimator for domain mean ps a T ,γ , using auxiliary character. Simulation study of the proposed estimator ps a T ,γ , has been made with conventional ratio synthetic estimator for domain mean ps a T ,−1, using auxiliary character in terms of simulated relative standard error (SRSE) and absolute relative bias (ARB). Simulation study shows that under synthetic assumption proposed estimator is more efficient than conventional ratio synthetic estimator for domain mean using auxiliary character.  

scholarly journals PENEREAPAN MODEL REGRESI THRESHOLD UNTUK PENINGKATAN EFISIENSI DALAM PENDUGAAN AREA KECIL

2020 ◽  
Vol 2019 (1) ◽  
pp. 84-92
Author(s):  
Azka Ubaidillah
Keyword(s):  
Root Mean Square Error ◽  
Mean Square Error ◽  
Root Mean Square ◽  
Standard Error ◽  
Linear Prediction ◽  
Relative Standard Error ◽  
Mean Square ◽  
Relative Standard

Pendugaan area kecil (SAE) dewasa ini berkembang cukup pesat seiring dengan meningkatnya kebutuhan atas penyediaan statistik yang terpercaya di area kecil, yaitu area dengan jumlah contoh (sampel) yang sedikit atau tidak mencukupi untuk dilakukan pendugaan secara langsung. Metode SAE dapat meningkatkan efektivitas contoh dengan “meminjam” kekuatan dari informasi area yang bertetanggaan dan pengaruh peubah penyertanya. Dalam aplikasinya, model Fay-Herriot menggunakan pendekatan Empirical Best Linear Prediction (EBLUP) banyak dilakukan karena sifat modelnya yang sederhana. Salah satu sifat sederhana dari model EBLUP adalah penggunaan hubungan linier antara peubah yang diamati dengan peubah penyertanya. Namun sering dijumpai bahwa hubungan linier tersebut belum cukup untuk meningkatkan efisiensi model SAE sebagai akibat pola yang terbentuk antara peubah amatan dan peubah penyertanya tidak linier. Paper ini menjelaskan salah satu alternatif cara untuk meningkatkan efisiensi model SAE dengan menerapkan model regresi threshold. Dari hasil simulasi dan aplikasi data pengeluaran perkapita makanan tingkat kabupaten/kota di Jawa Tengah tahun 2015 diperoleh keterangan bahwa model regresi threshold menghasilkan pendugaan dengan RMSE (root mean square error) dan RSE (relative standard error) yang lebih kecil dibandingkan model EBLUP. Hal ini menunjukkan bahwa penerapan model regresi threshold mampu untuk meningkatkan efisiensi dalam pendugaan area kecil.

scholarly journals Sequential Population Pharmacokinetic Modeling of Lopinavir and Ritonavir in Healthy Volunteers and Assessment of Different Dosing Strategies

2011 ◽  
Vol 55 (6) ◽  
pp. 2775-2782 ◽  
Author(s):  
Laura Dickinson ◽  
Marta Boffito ◽  
David Back ◽  
Laura Else ◽  
Nils von Hentig ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Standard Error ◽  
Performance Criteria ◽  
Maximum Effect ◽  
Population Pharmacokinetic ◽  
Relative Standard Error ◽  
Adequate Model ◽  
Relative Standard ◽  
Dosing Strategies ◽  
The Relationship

ABSTRACTNonlinear mixed-effects modeling was applied to explore the relationship between lopinavir and ritonavir concentrations over 72 h following drug cessation and also to assess other lopinavir and ritonavir dosing strategies compared to the standard 400-mg–100-mg twice-daily dose. Data from 16 healthy volunteers were included. Possible covariates influencing lopinavir and ritonavir pharmacokinetics were also assessed. Data were modeled first separately and then together by using individually predicted ritonavir pharmacokinetic parameters in the final lopinavir model. The model was evaluated by means of a visual predictive check and external validation. A maximum-effect model in which ritonavir inhibited the elimination of lopinavir best described the relationship between ritonavir concentrations and lopinavir clearance (CL/F). A ritonavir concentration of 0.06 mg/liter was associated with a 50% maximum inhibition of the lopinavir CL/F. The population prediction of the lopinavir CL/Fin the absence of ritonavir was 21.6 liters/h (relative standard error, 14.0%), and the apparent volume of distribution and absorption rate constant were 55.3 liters (relative standard error, 10.2%) and 0.57 h−1(relative standard error, 0.39%), respectively. Overall, 92% and 94% of the observed concentrations were encompassed by the 95% prediction intervals for lopinavir and ritonavir, respectively, which is indicative of an adequate model. Predictions of concentrations from an external data set (HIV infected) (n= 12) satisfied predictive performance criteria. Simulated lopinavir exposures at lopinavir-ritonavir doses of 200 mg-150 mg and 200 mg-50 mg twice daily were 38% and 65% lower, respectively, than that of the standard dose. The model allows a better understanding of the interaction between lopinavir and ritonavir and may allow a better prediction of lopinavir concentrations and assessments of different dosing strategies.

PENERAPAN MODEL FAY-HERRIOT PADA ESTIMASI PREVALENSI STUNTING LEVEL KECAMATAN DI NUSA TENGGARA BARAT TAHUN 2017

2020 ◽  
Vol 2019 (1) ◽  
pp. 74-83
Author(s):  
Muhammad Alfiyan Chairi Hakim ◽  
Siti Muchlisoh
Keyword(s):  
Standard Error ◽  
Small Area ◽  
Small Area Estimation ◽  
Relative Standard Error ◽  
Area Estimation ◽  
Relative Standard

Penerapan survei di Indonesia telah digunakan oleh banyak pihak, salah satunya adalah Kementerian Kesehatan (Kemenkes) dalam melaksanakan Pemantauan Status Gizi (PSG). Karakteristik yang diestimasi dari survei ini salah satunya adalah angka prevalensi stunting pada balita, akan tetapi level estimasi yang dapat disajikan hanya hingga level kabuapten/kota. Penelitian ini bertujuan untuk mengestimasi angka prevalensi stunting hingga ke level wilayah yang lebih rendah yaitu pada tingkat kecamatan dengan menerapkan metode small area estimation menggunakan model Fay-Herriot. Data yang digunakan pada penelitian ini berasal dari data mentah PSG Kemenkes dan juga Potensi Desa (PODES) 2014 yang dilaksanakan oleh BPS. Hasil dari penelitian ini menunjukkan bahwa model yang paling baik adalah EBLUP Fay-Herriot dengan variabel penyerta berbentuk jumlah. Hal ini berdasarkan nilai dari relative standard error serta rata-rata nilai gamma yang dihasilkan lebih rendah dari metode lainnya seperti estimasi langsung dan juga EBLUP Fay-Herriot dengan variabel penyerta berbentuk rasio. Kemudian berdasarkan hasil model terbaik didapatkan kecamatan dengan angka prevalensi stunting tertinggi adalah Kecamatan Praya dengan 60,83 persen, sedangkan yang terendah adalah Kecamatan Aikmel dengan 17,75 persen. Dari hasil penelitian, pemerintah diharapkan mengutamakan kebijakan penurunan stunting pada daerah-daerah dengan angka prevalensi stunting yang tinggi.

Point-Counting Technique for Fission-Track Dating of Tephra Glass Shards, and Its Relative Standard Error

1999 ◽  
Vol 51 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Giulio Bigazzi ◽  
Rex F. Galbraith
Keyword(s):  
Standard Error ◽  
Fission Track ◽  
Track Density ◽  
Relative Standard Error ◽  
Fission Track Dating ◽  
Point Counting ◽  
Counting Technique ◽  
Glass Shard ◽  
Relative Standard ◽  
Simplified Procedure

AbstractFission-track dating of glass is potentially an efficient technique for tephrochronological studies. However, most glasses from Quaternary tephra have very low spontaneous track densities and track counting is laborious. The point-counting technique is a simplified procedure for evaluating fission-track areal densities in a glass shard population that allows the analyst to count larger numbers of tracks in significantly shorter times. A field of view is coded as 1 if its center is on glass and is 0 otherwise, and the total area of glass is estimated by counting the number of 1's. Under simple assumptions, the binomial distribution appears to provide a reasonable evaluation of the additional experimental error in a fission-track density determination by this technique. Glass shard populations have been simulated, assuming that glass areas are random samples from distributions analogous to real ones. The effect of variation in glass area on the relative standard error of the estimated track density is found to be small. The point-counting technique significantly enhances the potential of fission-track dating, especially for very low track densities typical of most Quaternary tephra, as the additional error associated with its use is largely counterbalanced by the greater number of tracks that can be counted.

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