Detection of Safety Deterioration in a Series of Accident Counts

1996 ◽  
Vol 1542 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Ezra Hauer
Keyword(s):  
Random Variables ◽  
Detailed Examination ◽  
Statistical Test ◽  
Sudden Increase ◽  
Identification Procedure ◽  
Accident Frequency ◽  
Test Of Significance ◽  
The Mean ◽  
The Difference ◽  
Over Time

The task is to develop a workable procedure with the object of detecting sites where the mean accident frequency has increased over time to more than what can be attributed to changes in traffic or to general trends. Two kinds of increase are to be detected: a steady but gradual deterioration and a sudden increase in mean accident frequency at an unknown time. The procedure is to be applied to many sites, with the detected sites subsequently examined in detail. Both the gradual and the sudden increase in accident frequency are to be detected by a statistical test of significance for the difference between the means of two Poisson random variables. The software for doing such tests of significance has been developed and is available. An identification procedure is suggested to take account of (a) the number of sites that can be practically subjected to detailed examination and (b) the marginal yield of correctly identified sites.

scholarly journals Discrepancies in International Normalized Ratio Results between Instruments: A Model to Split the Variation into Subcomponents

2010 ◽  
Vol 56 (10) ◽  
pp. 1618-1626 ◽  
Author(s):  
Una Ø Sølvik ◽  
Per H Petersen ◽  
Grete Monsen ◽  
Anne V Stavelin ◽  
Sverre Sandberg
Keyword(s):  
Point Of Care ◽  
International Normalized Ratio ◽  
Patient Specific ◽  
Specific Effects ◽  
Warfarin Treatment ◽  
Analytical Imprecision ◽  
The Mean ◽  
The Difference ◽  
Analytical Variation ◽  
Over Time

BACKGROUND Observed differences between results obtained from comparison of instruments used to measure international normalized ratio (INR) have been higher than expected from the imprecision of the instruments. In this study the variation of these differences was divided into subcomponents, and each of the subcomponents was estimated. METHODS Blood samples were collected at 4 different patient visits from each of 36 outpatients who were receiving warfarin treatment and were included in the study. INR was determined on 1 laboratory instrument (STA Compact®) and 3 point-of-care instruments (Simple Simon®PT, CoaguChek®XS, and INRatio™). All 4 INR instruments were compared in pairs. Linear regression was used to correct for systematic deviations. The remaining variation of the differences was subdivided into between-subject, within-subject, and analytical variation in an ANOVA nested design. RESULTS The mean difference between instruments varied between 1.0% and 14.3%. Between-subject variation of the differences (expressed as CV) varied between 3.3% and 7.4%, whereas within-subject variation of the differences was approximately 5% for all 6 comparisons. The analytical imprecision of the differences varied between 3.8% and 8.6%. CONCLUSIONS The differences in INR between instruments were subdivided into calibration differences, between- and within-subject variation, and analytical imprecision. The magnitude of each subcomponent was estimated. Within results for individual patients the difference in INR between 2 instruments varied over time. The reasons for the between- and within-subject variations of the differences can probably be ascribed to different patient-specific effects in the patient plasma. To minimize this variation in a monitoring situation, each site and patient should use results from only 1 type of instrument.

scholarly journals EVALUATION OF THE CONVERGENCE SPEED IN THE LAW OF LARGE NUMBERS FOR GAMMA-DISTRIBUTED SEQUENCES

2018 ◽  
pp. 28-54 ◽  
Author(s):  
Georgiy Aleksandrovich Popov
Keyword(s):  
Distribution Function ◽  
Law Of Large Numbers ◽  
Random Variables ◽  
Mean Value ◽  
Minimum Volume ◽  
Average Value ◽  
Large Numbers ◽  
The Mean ◽  
The Law ◽  
The Difference

The paper considers the problem of estimating the rate of convergence in the law of large numbers for the case when the initial set of random variables is distributed according to the law of the gamma distribution. The problem is urgent due to the fact that with a small number of initial random variables, accurate and close to the true values are the values obtained on the basis of averaging, in particular, if the receipt of each additional value is associated with significant resource costs. The main result of the paper contains estimates for the modulus of difference in distribution function of the mean value for the set of N random variables in the original population, where N is arbitrary, and distribution function of their limiting value, which is a constant (mean value). The result includes three cases: when the argument of distribution function is greater than the average value; when it is equal to it and when it is less than the average value. Estimates are obtained for the modulus of difference of distributions, which depend not only on the number of random variables N, but also on the argument of distribution function. The dependence of the obtained estimate on the argument of distribution function has an exponential character, and on the volume of the set N this dependence makes about the root of N. For convenience of practical application, and also for solving the inverse problem on the basis of the obtained result, estimating the modulus of the difference of distributions is simplified. On the basis of the simplified estimates obtained, the solution of the following inverse problem is given: to find the minimum volume of the string N at which the modulus of the difference of distributions (the accuracy of estimating the mean value on the basis of the mean value) does not exceed a given (small) value. The paper presents a formula for finding the specified minimum volume N, and an algorithm for finding the exact value of N for the estimate under consideration.

scholarly journals Perbedaan Pengaruh Antara Penggunaan Abm Kruk Dengan Prostesis Terhadap Mobilitas Pasien Pasca Amputasi Transtibial

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Yopi Harwinanda Ardesa ◽  
Cica Tri Mandasari Ningsih
Keyword(s):  
Research Design ◽  
Comparison Group ◽  
Statistical Test ◽  
P Value ◽  
Test Results ◽  
Patient Mobility ◽  
Transtibial Amputation ◽  
Group Research ◽  
The Mean ◽  
The Difference

Background: To know the difference between using crutches utch and prosthesis on patient mobility after transtibial amputation, Research Design is a type of pre-experimental study with static comparison group research design. The subjects of this study were transtibial amputation patients divided into two groups. Each group consists of 15 people. Methods: The type of group in this study is a paired group in which one person gets two treatments. PT Kuspito Ortotik Prostetik Karanganyar, Time: June to October 2017. One person gets two treatments in the form of Kruk and prosthesis, prosthesis user will be tested with AMPpro test and Kruk user usage will be tested using AMPnopro, Measurements: AMPpro 20 test and AMPnopro 21 test, different test with Wilcoxon Signed Ranks Test. Results: Showed an average balance in the crutches group (15,32) while the mean balance was in the prosthesis group (45,38). The result of the statistical test with man Whitney shows p-value 0,000 <0,05 so there is a difference in the effect of crutch and prosthesis on patient mobility after transtibial amputation. Conclusion: The results of this study indicate that there is a difference between the use of Kruk and the prosthesis of mobility, the mobility of the prosthesis user has a higher level at the level of k-4, while the Kruk level is the k-3 level.

Physiological changes in the size of the septal swell body correlate with changes in inferior turbinate size

2020 ◽  
Vol 134 (4) ◽  
pp. 323-327
Author(s):  
E H Wong ◽  
M Noussair ◽  
Z Hasan ◽  
M Duvnjak ◽  
N Singh
Keyword(s):  
Middle Turbinate ◽  
Inferior Turbinate ◽  
Normal Function ◽  
Mean Difference ◽  
Nasal Breathing ◽  
Area Of Interest ◽  
The Mean ◽  
The Difference ◽  
The Impact ◽  
Over Time

AbstractObjectiveThe nasal septal swell body is a normal anatomical structure located in the superior nasal septum anterior to the middle turbinate. However, the impact of the septal swell body in nasal breathing during normal function and disease remains unclear. This study aimed to establish that the septal swell body varies in size over time and correlates this with the natural variation of the inferior turbinates.MethodConsecutive patients who underwent at least two computed tomography scans were identified. The width and height of the septal swell body and the inferior turbinates was recorded. A correlation between the difference in septal swell body and turbinates between the two scans was performed using a Pearson's coefficient.ResultsA total of 34 patients (53 per cent female with a mean age of 58.3 ± 20.2 years) were included. The mean and mean difference in septal swell body width between scans for the same patient was 1.57 ± 1.00 mm. The mean difference in turbinate width between scans was 2.23 ± 2.52 mm. A statistically significant correlation was identified between the difference in septal swell body and total turbinate width (r = 0.35, p = 0.04).ConclusionThe septal swell body is a dynamic structure that varies in width over time in close correlation to the inferior turbinates. Further research is required to quantify its relevance as a surgical area of interest.

scholarly journals Dynamics of a Population Subject to Impulse Type Random Loss

2017 ◽  
Vol 71 (4) ◽  
pp. 298-302
Author(s):  
Jevgeņijs Carkovs ◽  
Kārlis Šadurskis
Keyword(s):  
Differential Equation ◽  
Population Growth ◽  
Population Size ◽  
Random Variables ◽  
Time Interval ◽  
Small Positive Parameter ◽  
The Mean ◽  
The Difference ◽  
Linear Differential ◽  
Independent Identically Distributed

Abstract We present a qualitative population growth analysis approach using the Pearl logistic population growth differential equation for a population with the intensity of birth a, stationary size K to instances of fast small random population size extractions proportional to εξn at random time moments τn, where ε is the small positive parameter. Assuming that the intervals τn − τn−1 are independent identically exponentially distributed random variables with the parameter λ / ε, and that ξn are the independent identically distributed positive random variables with the mean h and the variance b2, we analyse the population dynamics and the population asymptotic behaviour. We propose a probabilistic limit theorem based stochastic approximation algorithm for the qualitative analysis of the above model on any finite time interval. At first we derive the linear differential equation for mathematical expectation 𝔼{x(t)} of the population growth and the stochastic Ito differential equation for the normalised deviations (𝔼{x(t)} − x(t))ε−1/2. Assuming that the difference a − λh = εc is sufficiently small we derive the stochastic differential equation for the scaled population growth in accelerated time ε−1 Kx(t / ε)and prove that under condition 2c < λ(h2+b2) the population disappears with probability one, otherwise the distribution of the scaled population size with increasing time tends to the Gamma-distribution Γ(k,q) with the shape k = 2c/λ(h2 + b2) and the scale θ = λ(h2 + b2)/2c.

scholarly journals Variability Over Time of Normal-Sized Fetal Renal Pelvis During the Second Trimester Scan

2017 ◽  
Vol 03 (04) ◽  
pp. E131-E136
Author(s):  
Maria Røset ◽  
Harm-Gerd Blaas ◽  
Tove Fagerli ◽  
Torbjørn Eggebø
Keyword(s):  
Renal Pelvis ◽  
Intraclass Correlation ◽  
Second Trimester ◽  
Lower Range ◽  
The Mean ◽  
The Difference ◽  
Intraobserver Variation ◽  
Over Time ◽  
Anterior Posterior ◽  
Interobserver Variations

Abstract Purpose To investigate the variability of the normal-sized fetal renal pelvis (≤5 mm) over time and to analyze repeatability of measurements. Materials and Methods 98 fetal renal pelvises and 49 fetal urinary bladders were analyzed at a gestational age of 17–20 weeks at St. Olavs Hospital, Trondheim, Norway. The anterior-posterior diameter (APD) of the fetal renal pelvis and two diameters of the fetal bladder were measured with an interval of at least 30 min. Intra- and interobserver variations and variations over time and in association with bladder size were investigated. Results The mean difference in renal pelvis size between the first and second measurements was 0.09 mm (95% CI, −0.09 to 0.26 mm). The variation over time was ≤1 mm in 85% of cases and the renal pelvis was ≤4 mm in both the first and second examinations in 92% of cases. The intraclass correlation coefficient (ICC) was 0.54 (95% CI: 0.31 to 0.69). We did not observe any association between variation of bladder size and variation of APD. The difference in fetal renal pelvis size was ≤1 mm in 70% of observations for the first examiner and 58% for the second examiner. The intraobserver ICCs were 0.71 (95% CI: 0.62–0.78) and 0.60 (95% CI: 0.50–0.70) for the two observers respectively. The interobserver difference was ≤1 mm in 72% of cases and the interobserver ICC was 0.56 (95% CI: 0.34–0.71). Conclusion The variation of the APD of the fetal renal pelvis over time was small in fetuses with the APD in the lower range and can mainly be explained by intraobserver variation.

The Effect of Vocabulary Intervention on Text Comprehension: Who Benefits?

2019 ◽  
Vol 50 (4) ◽  
pp. 562-578 ◽  
Author(s):  
Dawna Duff
Keyword(s):  
Middle School ◽  
Reading Comprehension ◽  
Text Comprehension ◽  
Classroom Instruction ◽  
Vocabulary Instruction ◽  
Clinical Intervention ◽  
Vocabulary Knowledge ◽  
Vocabulary Intervention ◽  
The Mean ◽  
The Difference

Purpose Vocabulary intervention can improve comprehension of texts containing taught words, but it is unclear if all middle school readers get this benefit. This study tests 2 hypotheses about variables that predict response to vocabulary treatment on text comprehension: gains in vocabulary knowledge due to treatment and pretreatment reading comprehension scores. Method Students in Grade 6 ( N = 23) completed a 5-session intervention based on robust vocabulary instruction (RVI). Knowledge of the semantics of taught words was measured pre- and posttreatment. Participants then read 2 matched texts, 1 containing taught words (treated) and 1 not (untreated). Treated texts and taught word lists were counterbalanced across participants. The difference between text comprehension scores in treated and untreated conditions was taken as a measure of the effect of RVI on text comprehension. Results RVI resulted in significant gains in knowledge of taught words ( d RM = 2.26) and text comprehension ( d RM = 0.31). The extent of gains in vocabulary knowledge after vocabulary treatment did not predict the effect of RVI on comprehension of texts. However, untreated reading comprehension scores moderated the effect of the vocabulary treatment on text comprehension: Lower reading comprehension was associated with greater gains in text comprehension. Readers with comprehension scores below the mean experienced large gains in comprehension, but those with average/above average reading comprehension scores did not. Conclusion Vocabulary instruction had a larger effect on text comprehension for readers in Grade 6 who had lower untreated reading comprehension scores. In contrast, the amount that children learned about taught vocabulary did not predict the effect of vocabulary instruction on text comprehension. This has implications for the identification of 6th-grade students who would benefit from classroom instruction or clinical intervention targeting vocabulary knowledge.

Efficacy and Safety of Oral Ivermectin and Topical Permethrin in the Treatment of Scabies

2020 ◽  
Vol 33 (1) ◽  
pp. 41-47
Author(s):  
Mohsena Akhter ◽  
Ishrat Bhuiyan ◽  
Zulfiqer Hossain Khan ◽  
Mahfuza Akhter ◽  
Gulam Kazem Ali Ahmad ◽  
...  
Keyword(s):  
Skin Diseases ◽  
Close Contact ◽  
Randomized Study ◽  
Sarcoptes Scabiei ◽  
Efficacy And Safety ◽  
Common Skin ◽  
Group A ◽  
The Mean ◽  
The Difference ◽  
Group B

Background: Scabies is one of the most common skin diseases in our country. It is caused by the mite Sarcoptes scabiei var hominis, which is an ecto-parasite infesting the epidermis. Scabies is highly contagious. Prevalence is high in congested or densely populated areas. Individuals with close contact with an affected person should be treated with scabicidal which is available in both oral and topical formulations. The only oral but highly effective scabicidal known to date is Ivermectin. Amongst topical preparations, Permethrin 5 % cream is the treatment of choice. Objective: To evaluate the efficacy & safety of oral Ivermectin compared to topical Permethrin in the treatment of scabies. Methodology: This prospective, non-randomized study was conducted at the out-patient department of Dermatology and Venereology of Shaheed Suhrawardy Medical College & Hospital over a period of 6 months, from August 2016 to January 2017. The study population consisted of one hundred patients having scabies, enrolled according to inclusion criteria. They were divided into two groups. group A was subjected to oral Ivermectin and the group B to Permethrin 5% cream. Patients were followed up on day 7 and 14 for assessment of efficacy and safety. Result: The mean scoring with SD in group A (Ivermectin) and group B (Permethrin) were 8.26 ± 2.22 and 7.59 ± 2.01 respectively at the time of observation. The difference between the mean score of the two group is not significant (p=0.117) the mean scoring with SD in group A and group B were 4.54 ± 2.05 and 1.64 ± 1.84 respectively at 7thdays. The difference between the mean score of the two group is significant (p<0.001). The mean scoring with SD in group A and group B were 2.68± 2.35 and .36± 1.10 respectively at 14th day difference between the mean score of the group is significant (p<0.001). Conclusion: Topical application of permethrin 5% cream is more effective and safer than oral Ivermectin in the treatment of scabies. TAJ 2020; 33(1): 41-47

EFFECTS OF SYNTHETIC LH/FSH-RELEASING HORMONE (LRH) ON PLASMA LH AND FSH IN AMENORRHOEIC WOMEN

1974 ◽  
Vol 75 (4) ◽  
pp. 647-652 ◽  
Author(s):  
G. Rannevik ◽  
J. Thorell
Keyword(s):  
Urinary Excretion ◽  
Initial Response ◽  
Releasing Hormone ◽  
The Mean ◽  
The Difference ◽  
Serial Measurements

ABSTRACT Eight amenorrhoeic women were given 100 μg synthetic LRH (Hoechst) iv and im, respectively, at an interval of 2 weeks. Four of the women received the iv injection first and four the im injection. The urinary excretion of oestrogens and pregnanediol was low and unaltered throughout the test weeks. The effects of LRH were compared by serial measurements of the plasma LH and FSH during 8 h. The initial response of LH for up to 25 min and that of FSH for up to 60 min were equal whether LRH was given iv or im. The difference appeared later. Four hours after the injection the mean increase of LH to iv injection was 0.5 ng/ml (N. S.), while that to im injection was 1.9 ng/ml (P < 0.01). The corresponding values for FSH were 1.3 (P < 0.05) and 3.2 (P < 0.001). The effect of LRH administration im was thus found to be larger and more prolonged.

The Distinction between [P] and [S]

2017 ◽  
Author(s):  
Galen Strawson
Keyword(s):  
Personal Identity ◽  
Radical Change ◽  
Legal Responsibility ◽  
The Difference ◽  
Definition Of ◽  
Over Time

This chapter examines the difference between John Locke's definition of a person [P], considered as a kind of thing, and his definition of a subject of experience of a certain sophisticated sort [S]. It first discusses the equation [P] = [S], where [S] is assumed to be a continuing thing that is able to survive radical change of substantial realization, as well as Locke's position about consciousness in relation to [P]'s identity or existence over time as [S]. It argues that Locke is not guilty of circularity because he is not proposing consciousness as the determinant of [S]'s identity over time, but only of [S]'s moral and legal responsibility over time. Finally, it suggests that the terms “Person” and “Personal identity” pull apart, in Locke's scheme of things, but in a perfectly coherent way.

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