• Title/Summary/Keyword: Reassessment

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Maximum tolerated dose estimation using continual reassessment method in Phase I Clinical Trial (연속재평가방법에 가속화 단계를 적용한 MTD 추정법)

  • Kwon, Dohee;Kim, Dongjae
    • The Korean Journal of Applied Statistics
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    • v.32 no.5
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    • pp.741-752
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    • 2019
  • The purpose of a Phase I Clinical Trial is to determine the maximum tolerated dose (MTD). MTD is important because it affects subsequent clinical trials; however, the existing method has a problem due to an inadequate dose allocated to patients. In this paper, an MTD estimation method is proposed to complement the problems of the existing MTD estimation method. The suggested method applies the initial acceleration step to the modified continual reassessment method. Monte Carlo Simulation Study is adapted to compare a suggested MTD estimation method with the standard design and the modified continual reassessment method.

Investigation on the modified continual reassessment method in phase I clinical trial (1상 임상실험에서 수정된 CRM에 대한 연구)

  • 강승호
    • The Korean Journal of Applied Statistics
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    • v.15 no.2
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    • pp.323-336
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    • 2002
  • In this paper we consider the modified continual reassessment method in which a cohort consists of three patients. Simulation has been a main research tool in the investigation of CRM. In this paper we propose complete enumeration as an alternative of simulation. Using new method we show that the expected toxicity rate at the MTD converges to the target toxicity rate well as the sample size increases.

Reassessment on numerical results by the continuum model (연속체모델에 의한 수치해석결과에 대한 재평가)

  • Jeong, Jae-Dong;Yu, Ho-Seon;No, Seung-Tak;Lee, Jun-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.12
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    • pp.3926-3937
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    • 1996
  • In recent years there has been increased interest in the continuum model associated with the solidification of binary mixtures. A review of the literature, however, shows that the model verification was not sufficient or only qualitative. Present work is conducted for the reassessment of continuum model on the solidification problems of binary mixtures widely used for model validation. In spite of using the same continuum model, the results do not agree well with those of Incropera and co-workers which are benchmark problems typically used for validation of binary mixture solidification. Inferring from the agreement of present results with the analytic, experimental and other model's numerical results, this discrepancy seems to be caused by numerical errors in applying continuum model developed by Incropera and co-workers, not by the model itself. Careful examination should be preceded before selecting validation problems.

Maximum Tolerated Dose Estimation by Stopping Rule and SM3 Design in a Phase I Clinical Trial (제 1상 임상시험에서 멈춤 규칙과 SM3 디자인을 이용한 최대허용용량 추정법)

  • Kim, Byoungchan;Kim, Dongjae
    • The Korean Journal of Applied Statistics
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    • v.27 no.1
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    • pp.13-20
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    • 2014
  • Phase I Clinical Trials estimate a Maximum Tolerated Dose(MTD). In this paper, an MTD estimation method applied stopping rule is proposed for Phase I Clinical Trials. The suggested MTD estimation method is compared to the Continual Reassessment Method(CRM) method using a Monte Carlo simulation study.

Reassessment of Cambaroides dauricus and C. schrenckii (Crustacea: Decapoda: Cambaridae)

  • Kawai, Tadashi;Machino, Yoichi;Ko, Hyun-Sook
    • Animal cells and systems
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    • v.7 no.3
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    • pp.191-196
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    • 2003
  • Taxonomic confusion has been presented within freshwater crayfishes of the genus Cambaroides since Starobogatov published morphological definition and revision of the group in 1995. He suggested that Cambaroides should be revised: the C. dauricus, contained three species C. dauricus, C. wladiwostokiensis, and C. koshewnikowi; the C. schrenckii with two. species C. schrenckii and C. sachalinensis. Also Straovogatov did not take into account the previous data. of crayfish distributions. In order to. clear up the confusion, the taxonomy of crayfish sampled from Mongolia, Russia, China, and North Korea was reassessed. Starovogatov's key could not lead to the correct identification. Also, detailed observations of apical robe of the male first pleopod did not support the taxonomy on the genus Cambaroides proposed by Starobogatov in 1995. However, some local variations of morphology exist in rostrum, pleuron, and telson of Asian crayfish. Future studies should be concentrated on whether there are geographical clines of morphology or if taxonomic subdivision is necessary.

CONSISTENCY AND ASYMPTOTIC NORMALITY OF A MODIFIED LIKELIHOOD APPROACH CONTINUAL REASSESSMENT METHOD

  • Kang, Seung-Ho
    • Journal of the Korean Statistical Society
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    • v.32 no.1
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    • pp.33-46
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    • 2003
  • The continual reassessment method (CRM) provides a Bayesian estimation of the maximum tolerated dose (MTD) in phase I clinical trials. The CRM has been proposed as an alternative design of the standard design. The CRM has been modified to improve practical feasibility and, recently, the likelihood approach CRM has been proposed. In this paper we investigate the consistency and asymptotic normality of the modified likelihood approach CRM in which the maximum likelihood estimate is used instead of the posterior mean. Small-sample properties of the consistency is examined using complete enumeration. Both the asymptotic results and their small-sample properties show that the modified CRML outperforms the standard design.

Influence of Fatigability on the Timing of Reassessment in the Treatment of Posterior Canal Benign Paroxysmal Positional Vertigo (후반고리관 양성돌발두위현훈의 치료에서 재평가 시기에 대한 피로 현상의 영향)

  • Kim, Chang-Hee;Shin, Jung Eun;Shin, Yong Gook;Song, Mee Hyun;Shim, Dae Bo
    • Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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    • v.61 no.12
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    • pp.658-662
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    • 2018
  • Background and Objectives The early assessment of treatment is not done for benign paroxysmal positional vertigo (BPPV) since the well-known phenomenon of fatigability after a repeated positional test can mimic successful treatment. The aim of this study is to evaluate the clinical implication of 'fatigability' after Epley maneuver and to identify the therapeutic efficacy of Epley maneuver in posterior canal BPPV (PC-BPPV). Subjects and Method This study was prospectively conducted by two dizziness clinics on 51 consecutive patients diagnosed with PC-BPPV. All patients included in the study received Epley maneuver treatment. The therapeutic results were reassessed immediately after a single trial of Epley maneuver. After 30 minutes, results were reassessed repeatedly to confirm the fatigability of diagnostic procedure immediately after treatment. If the treatment was not successful after 30 minutes, Epley maneuver was repeatedly performed until complete resolution. Results Immediately after the first maneuver, 45 of 51 (88.2%) patients had neither vertigo nor nystagmus during the positional test. All patients demonstrated complete resolution after receiving one to three Epley maneuvers on the day of diagnosis. 'Fatigability (false negative result)' was confirmed for only one case (1 of 6 patients, 16.7%), in which nystagmus was observed after 30 minutes but not identified immediately after the first Epley maneuver. Conclusion The therapeutic efficacy of Epley maneuver is very high in PC-BPPV. Considering the possibility of fatigability when reassessment is performed immediately after therapeutic maneuver, clinicians should avoid assessing the outcome immediately after treatment in patients with PC-BPPV.

Change of Growth Indicators by the Treatment of Korean Medicine (한의 성장 치료에 따른 성장 지표 변화)

  • Oh Hye In;Lee Hyun Hee;Jeong Ji Eun;Lee Hye Lim
    • The Journal of Pediatrics of Korean Medicine
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    • v.37 no.3
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    • pp.35-48
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    • 2023
  • Objectives We aimed to analyze changes in growth indicators before and after Korean medicine treatment in patients treated at the pediatric department of a hospital. Methods We analyzed the medical records of children and adolescents under 18 years of age who underwent growth assessment between January 1, 2017 and December 31, 2022. Results A total of 21 patients were selected for this study. After treatment, there was a significant increase in the height percentile, whereas bone age-chronological age (BA-CA) and predicted adult height (PAH) did not show significant changes. No major adverse reactions were observed during the treatment. Growth reassessment was conducted twice for 10 participants. When comparing the growth indicators between the assessment sessions, the height percentile showed an increasing trend between the initial and the first growth reassessment. However, there were no significant differences between BA-CA and PAH across the different assessment periods. Conclusions There is a need to establish evidence for the efficacy and safety of continuous Korean medicine growth treatment through the long-term observation of growth indicators in patients undergoing treatment for two or more periods, as well as observational studies on liver and renal function indicators.

Taxonomic Reassessment of the Genus Padina (Dictyotales, Phaeophyta) from the Gulf of California

  • Riosmena-Rodriguez, Rafael;Paul-Chavez, Litzia;Hernandez-Carmona, Gustavo;Lopez-Vivas, Juan Manuel;Casas-Valdez, Margarita
    • ALGAE
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    • v.24 no.4
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    • pp.213-229
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    • 2009
  • A monographic reassessment of Padina Adanson species from the Gulf of California was developed based on an exhaustive review of the character and characters states that have been used to delimit species in recent and historically valuable collections. Eight names (P. caulescens Thivy in Taylor, P. concrescens Thivy in Taylor, P. crispata Thivy in Taylor, P. durvillaei Bory Saint-Vincent, P. gymnospora [Kutzing] Sonder, P. mexicana Dawson, P. tetrastromatica Hauck and P. vickersiae Hoyt in Howe) were reported from the region. An analysis of 1,200 specimens led to the conclusion that only three species (P. durvillaei, P. concrescens and P. mexicana) can be recognized for the area based on four discriminating characters: presence of calcium carbonate in the cell wall; number of medullary cell layers in the basal area; number of medullary cell layers in the middle part and presence/absence of cortical cells. Comparative analysis of the species in the Gulf of California in relation to other recently evaluated species has shown a clear distinction among them suggesting Padina species were overestimated in our area.