scholarly journals Identification of Minimum Effective Dose based on Ratio of a Normally Distributed Data under Heteroscedasticity

2021 ◽  
Vol 16 (2) ◽  
pp. 2719-2731
Author(s):  
Emmanuel Dodzi Kpeglo ◽  
Michael Jackson Adjabui ◽  
Jakperik Dioggban
Keyword(s):  
Effective Dose ◽  
Practical Importance ◽  
Food Additives ◽  
Distributed Data ◽  
Familywise Error Rate ◽  
Minimum Effective Dose ◽  
Population Means ◽  
Modern Drug ◽  
Dose Levels ◽  
Normally Distributed

Efficacy and safety study is of practical importance in modern drug development. It is a key component in evaluating the safety of food additives or pesticides, and assessing the effectiveness and safety of drugs. In most of the various statistical procedures, homogeneity of variances among different dose levels was required. This paper without a need for multiplicity adjustment proposes a stepwise confidence set procedure for estimating Minimum Effective Dose (MED) of drugs based on ratio of population means for normally distributed data under heteroscedasticity. The procedure employed Fieller’s (1954) method and obtained individual confidence intervals for identification of MED. The procedure is applied to a data of an experiment that was published by Ruberg (1989) where the effect of a new compound is measured by an increase in the weight of a particular organ in mice. Simulation study was carried out and results indicate that the procedure controls the familywise error rate (FWER) strongly. Power of the procedure increases with increasing ratio of means and sample size.

scholarly journals Identification of Minimum Effective Dose based on Ratio of a Normally Distributed Data under Heteroscedasticity

2021 ◽  
Vol 16 (2) ◽  
pp. 2717-2729
Author(s):  
Emmanuel Dodzi Kpeglo ◽  
Michael Jackson Adjabui ◽  
Jakperik Dioggban
Keyword(s):  
Effective Dose ◽  
Practical Importance ◽  
Food Additives ◽  
Distributed Data ◽  
Minimum Effective Dose ◽  
Population Means ◽  
Modern Drug ◽  
The Family ◽  
Dose Levels ◽  
Normally Distributed

Efficacy and safety study is of practical importance in modern drug development. It is a key component in evaluating the safety of food additives or pesticides, and assessing the effectiveness and safety of drugs. In most of the various statistical procedures, homogeneity of variances among different dose levels was required. This paper without a need for multiplicity adjustment proposes a stepwise confidence set procedure for estimating Minimum Effective Dose (MED) of drugs based on ratio of population means for normally distributed data under heteroscedasticity. The procedure employed Fieller’s (1954) method and obtained individual confidence intervals for identification of MED. The procedure is applied to a data of an experiment that was published by Ruberg (1989) where the effect of a new compound is measured by an increase in the weight of a particular organ in mice. Simulation study was carried out and results indicate that the procedure controls the family-wise error rate (FWER) strongly. Power of the procedure increases with increasing ratio of means and sample size.

scholarly journals Identifying Minimum Effective Dose Under Heteroscedasticity

2021 ◽  
pp. 34-43
Author(s):  
Michael J. Adjabui ◽  
Jakperik Dioggban ◽  
Irene D. Angbing
Keyword(s):  
Effective Dose ◽  
Simulation Study ◽  
Error Rate ◽  
Familywise Error Rate ◽  
Minimum Effective Dose ◽  
Sample Sizes ◽  
Balanced Design ◽  
Unbalanced Design ◽  
Critical Requirement

We propose a stepwise confidence procedure for identifying minimum effective dose (MED) without multiplicity adjustment.Stepwise procedures strongly control the familywise error rate (FWER) which is a critical requirement for statistical methodologies in identification of MED. The partitioning principle is invoked to validate the control of the FWER. Our simulation study indicates that the FWER was properly controlled in the case with balanced design but failed in some cases of sample sizes for situations of unbalanced design. In addition, the power of the procedure increases with increasing mean of ratio differences and the sample sizes.

The minimum effective dose of praziquantel in treatment of Hymenolepis diminuta in rats

1995 ◽  
Vol 69 (1) ◽  
pp. 91-92 ◽  
Author(s):  
P.C. Fan ◽  
A. Ito
Keyword(s):  
Effective Dose ◽  
Hymenolepis Diminuta ◽  
Minimum Effective Dose ◽  
Faecal Examination ◽  
Faecal Samples

AbstractTo determine the minimum effective dose of praziquantel against Hymenolepis diminuta in rats, 5.0 mg/kg, 2.5 mg/kg, 1.0 mg/kg, 0.5 mg/kg, 0.1 mg/kg, or 0.05 mg/kg praziquantel were given to each of five experimentally infected rats in six groups. Faecal samples from each rat were examined for worms on day 10. Based on the results of faecal examination and autopsy, the minimum effective dose of praziquantel against Hymenolepis diminuta in rats was determined to be 0.5 mg/kg.

Comparison of GEE, MINQUE, ML, and REML Estimating Equations for Normally Distributed Data

2001 ◽  
Vol 55 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Chi-tsung Wu ◽  
Marcia L Gumpertz ◽  
Dennis D Boos
Keyword(s):  
Estimating Equations ◽  
Distributed Data ◽  
Normally Distributed

Diagnostic and therapeutic applications of radiopharmaceutical agents: The medical use of radioactive iodine (I-131) therapy for hyperthyroidism treatments.

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Hasnae WATLA ◽  
Mohamed LAHKIM ◽  
Mohamed Amine CHAD
Keyword(s):  
Nuclear Medicine ◽  
Effective Dose ◽  
Radioactive Iodine ◽  
Minimum Effective Dose ◽  
Therapeutic Aspect ◽  
Therapeutic Applications ◽  
Medical Centers ◽  
Iodine 131 ◽  
Radiopharmaceutical Agents

The treatment of hyperthyroidism with iodine-131 has been recognized on nuclear medicine as simple, effective and inexpensive, this kind of radiopharmaceutical is chosen by the majority of medical centers by administering a minimum effective dose enabling euthyroidism to be easily compensated as quickly as possible while avoiding radiation problems. In this mini_review, we are going to explain the diagnostic and therapeutic aspect of radiopharmaceuticals by taking an example of radioiodine I-131 and its role on hyperthyroidism treatment .

1.2 Method of constant stimuli (Method of frequency) By the Method of Frequency the stimulus range is selected in discrete intervals so that the frequency of positive answers is distributed over the range between 1% and 99%. In general, the frequency of positive res­ ponses either for an individual or for a group, is cumulatively normally distributed over a geometric intensity continuum. The absolute odor thre­ shold can then be defined as the effective dose corresponding to an arbi­ trarily selected frequency of positive responses, ordinarily 50% : ED^: Effective dose at the 50% level. 3.1.3 Signal detection The Signal Detection principle is a determination of the relation­ ship between hits and false alarms. In determining signal detectability, a stimulus or a few stimuli are presented in random order, alternating with noise. Since sensory impressions resulting frcm the presentation of stimulus versus noise are assumed to be normally distributed over the same intensity continuum and to have the same dispersion, the index of detectability d' for p (hits) minus p (false) indicates the extent to which the two distributions overlap. 3.2 Indication of response 3.2.1 "Yes" or "no" response In the classical evaluation yes-no answers are dependent on the sub­ jects1 honesty and motivation among other factors. However, yes-no ans­ wers may be evaluated if they are presented a sufficiently large number of times alternating with blanks. 3.2.2 forced choice technique One method of controlling response perseveration and otter antici­ pation factors is to use a forced choice response indication based on two or more response categories. In the measurement of odors the panelist has to report the temporal position of positive stimuli in a series of randan blanks. If the concentration is below the threshold, the test sub­ jects will guess. As the odorant concentration will increase, the rela­ tive cumulative frequency for identification of the correct sample will be greater. In order to determine the relative odor recognition a cor­ rection must be made. 3.3 Size of stimulus intervals 3.3.1 Concentration intervals In selecting the stimulus continuum in threshold determination, the relation between just noticeable difference in relation to the intensity of stimuli is of interest. In accordance with Weber's law this quotient is assumed to be a constant. Therefore it would appear best to determine absolute thresholds on an intensity continuum in the form of a gecxnetric progression. 3.2.2 Time intervals Because of adaptation processes the exposure time until reaching a decision should be limited. Also the interval between two stimuli must be observed.

1986 ◽  
pp. 71-71
Keyword(s):  
Signal Detection ◽  
Effective Dose ◽  
Random Order ◽  
Stimulus Range ◽  
Forced Choice ◽  
Just Noticeable Difference ◽  
False Alarms ◽  
Choice Response ◽  
Temporal Position ◽  
Normally Distributed
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