• Journal of the Korean Data and Information Science Society
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• 제22권3호
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• pp.605-612
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• 2011

In multi-center randomized clinical trial the treatment eect may be changed over centers. It is thus important to investigate the heterogeneity in treatment eect between centers. For this, uncorrelated random-eect models assuming independence between random-eect terms have been often used, which may be a strong assumption. In this paper we propose a correlated frailty modelling approach of investigating such heterogeneity using the hierarchical-likelihood method when the outcome is time-to-event. In particular, we show how to construct a proper prediction interval for frailty, which explores graphically the potential heterogeneity for a treatment-by-center interaction term. The proposed method is illustrated via numerical studies based on data from the design of a multi-center clinical trial.

• Communications for Statistical Applications and Methods
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• 제5권3호
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• pp.707-722
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• 1998

This paper evaluates a new clinical trial designs for low infection rate disease. This type of sparse disease reaction makes the traditional two sample t-test or Wilcoxon rank-sum test inefficient compared to a new test suggested. The new test, which is based solely on the larger changes, is shown to be more effective than existing method by simulation for small samples. However, this test can be shown to be connected to the locally most powerful rank test under certain practical conditions. This design is motivated in testing the treatment effects in periodontal disease research.

• 한방비만학회지
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• 제12권1호
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• pp.48-58
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• 2012

Objectives These prescribing recommendations have been written to guide clinicians on the appropriate use of Bangpungtongseong-san(BT) and Bangkihwangki-tang(BH) in the treatment of obesity. These recommendation are aimed at providing evidence based information concerning diagnosis and management of obesity. Methods We collected all relevant references about treatment effect of BT and BH on obesity in the forms of meta-analysis, systematic review, randomized controlled trial, case-control study, observational study and practice guideline from international and domestic databases and paper journals. We examined treatment effect, side effects, recommendations for dose, indication and contraindication of BT and BH. Results The treatment effect of BT and BH on obesity has been proved through clinical trial. BT is indicated for obese patients (Body mass index, $BMI{\geq}25$) with strong abdomen and a tendency to constipation, BH is indicated for obese patients ($BMI{\geq}25$) with a fair skinned, soft muscled, edematous and sweat easily. Conclusion We wish the information contained in theses recommendations will help clinicians reach a reasonable and beneficial decision with evidence-based results. Further studies are strongly needed to develop better treatment strategies for herbal medicines on obesity.

• 대한방사성의약품학회지
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• 제10권1호
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• pp.83-96
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• 2024

Peptide-based radiopharmaceuticals have brought significant advancements in the diagnosis and treatment of various cancers, serving as a powerful tool in nuclear medicine. These radiopharmaceuticals utilize the high specificity of peptides for certain cell receptors, such as the prostate-specific membrane antigen in prostate cancer and somatostatin receptors in neuroendocrine tumors. This review paper aims to describe the clinical benefits of peptide-based radiopharmaceuticals, emphasizing their high target affinity, improved imaging quality, and therapeutic efficacy. By integrating ongoing research and clinical trial data, the innovative impact of peptide-based radiopharmaceuticals in nuclear medicine is highlighted.

• 응용통계연구
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• 제37권4호
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• pp.411-444
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• 2024

제 1상 임상시험의 목적은 사람이 견딜 수 있는 최대 허용 용량(maximum tolerated dose; MTD)을 결정하여 안전성이 허용되는 범위하에 충분히 높은 용량까지 올바르게 평가하는 것이 중요하다. MTD를 추정하는 방법은 알고리즘 기반, 모델 기반 및 모델 보조방법을 포함한 여러 가지 방법이 고안되었다. 본 논문에서는 기존 용량 탐색 방법의 단점을 보완하기 위해 연속 재평가 방법(continual reassessment method; CRM)에 기반한 새로운 용량 탐색 방법을 제안하여 다양한 문제 상황에서 기존 용량 탐색 방법들과의 성능을 비교하기 위해 시뮬레이션 연구를 수행하였다. 연구의 결과 MTD 추정에서의 정확도와 안전성을 높일 수 있고, 적은 시험대상자를 사용한다는 점에서 가장 우월한 성능을 보임을 확인하였다.

• 대한한방부인과학회지
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• 제24권3호
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• pp.171-189
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• 2011

Objectives: Female Sexual Dysfuction(FSD) is a common gynecologic condition and its prevalence is more higher than men. Despite its high prevalence and clinical importance, research on FSD is not enough in both of oriental and western medicine. The purpose of this study is to review research tendency of recent oriental medicine studies on FSD and to suggest the following research on FSD. Methods: We searched oriental medicine papers related to FSD published in the last 10 years(2001-2011) through Korean Medicine Gynecology Society database, KISS, RISS, NDSL, CNKI(China National Knowledge Infrastructure), and Pubmed. Results: 26 papers were searched, then 18 papers of them were related to Traditional Chinese Medicine(TCM), 8 papers of them were related to Korean Medicine(KM). In classification according to paper type, 16 papers were clinical study, 1 paper was experimental study, 2 papers were bibliographic study, and 7 papers were the other study. Then 5 papers of clinical study was Randomized Controlled Trial(RCT). Conclusion: There was a lack of oriental medicine research on FSD. On the base of this study, so further research is needed. Especially, Clinical trials such as RCT have strong objective evidence power in the viewpoint of Evidence Based Medicine(EBM) are needed.

• Communications for Statistical Applications and Methods
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• 제18권5호
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• pp.581-594
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• 2011

제 1상 임상시험 계획에서 신약제의 최대허용용량을 추정하기 위해 전통적 방법인 표준 3+3계획과 모형중심의 베이지안 방법을 적용시킨 연속재평가방법이 주로 사용되고 있다. 본 논문에서는 치료불응 또는 재발된 백혈병이나 골수형성 이상증후군 환자를 대상으로 시행한 제 1상 임상시험의 연구계획을 개관하였다. 단순한 표준 3+3계획으로 환자확보 기간이 길어져 연구를 완성하지 못하고 때 이르게 중단할 수밖에 없는 실정에 반하여, 최근에 제시된 표준 3+1+1계획과 Rolling-6 계획은 연구기간을 크게 단축시킬 수 있다. 제1상 임상시험의 용량수준 선택과정에서 너무 보수적인 연구자의 태도는 최대허용용량의 정확한 추정을 불가능하게 한다. 새로운 환자에게 투여할 용량수준을 결정할 시점에서 용량제한 독성반응이 아직 나타나지 않은 환자의 관측시간 및 늦게 나타나는 환자의 독성반응 시간을 모두 감안한 연속재평가방법인 TITE-CRM계획이 유용하며, 이러한 CRM계획으로 진행되는 임상시험 시행 중 모의실험으로 각 용량수준에서 용량제한 독성반응율이 과대 또는 과소 추정되는지를 파악할 수 있음이 장점이다. 백혈병환자 대상의 임상연구에서 채택되는 제 1상 임상시험의 여러 연구계획의 장, 단점을 제시한다.

• Communications for Statistical Applications and Methods
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• 제22권4호
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• pp.389-399
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• 2015

It is important not to overcalculate sample sizes for clinical trials due to economic, ethical, and scientific reasons. Kang and Kim (2014) investigated the accuracy of a well-known sample size calculation formula based on the approximate power for continuous endpoints in equivalence trials, which has been widely used for Development of Biosimilar Products. They concluded that this formula is overly conservative and that sample size should be calculated based on an exact power. This paper extends these results to binary endpoints for three popular metrics: the risk difference, the log of the relative risk, and the log of the odds ratio. We conclude that the sample size formulae based on the approximate power for binary endpoints in equivalence trials are overly conservative. In many cases, sample sizes to achieve 80% power based on approximate powers have 90% exact power. We propose that sample size should be computed numerically based on the exact power.

• Communications for Statistical Applications and Methods
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• 제15권5호
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• pp.727-735
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• 2008

Consider a clinical trial in which the main end-point is survival. Suppose after the start of the study an intermediate event occurs which may be influenced by a covariate(or treatment). In many clinical studies the occurrence of an intermediate event may change the survival distribution. This investigation develops two-stage model which, in the first stage, models the effect of covariate on the intermediate event and models the relationship between survival time and covariate as well as the intermediate event. In this paper, the two-stage model is presented in order to model intermediate event and a test based on this model is also provided. A numerical simulations are carried out to evaluate its overall significance level.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3284-3288
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• 2013

This paper describes first development and validation of pentafluorophenylprophyl ligand-based liquid chromatography coupled to tandem mass spectrometry (PFPLC-MS/MS) method to determine metformin, a highly polar compound, in human plasma. Metformin and Phenformin (internal standard) were extracted from human plasma 50 ${\mu}L$ with a single-step protein precipitation. The chromatographic separation was performed using a linear gradient elution of mobile phase involving 5.0 mM ammonium formate solution with 0.1% formic acid (A) and acetonitrile (B) over 3.0 min of run time on a Phenomenex Luna PFP column. The detection was performed using a triple-quadrupole tandem mass spectrometer (Waters Quattro micro) with electrospray ionization in the mode of positive ionization and multiple-reaction monitoring (MRM). The developed method was validated with 5.0 ng/mL of lower limit of quantification (LLOQ). The calibration curve was linear over 5-3000 ng/mL of the concentration range ($R^2$ > 0.99). The specificity, selectivity, carry-over effect, precision, accuracy and stability of the method met the acceptance criteria. The method developed in this study had had rapidness, simplicity and ruggedness. The reliable method was successfully applied to high throughput analysis of real samples for a practical purpose of a pharmacokinetic study.