• 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.

• Journal of Korean Medicine for Obesity Research
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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.

• The Journal of Korean Obstetrics and Gynecology
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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

The traditional method of 3+3 standard design and model-based Bayesian continual reassessment method (CRM) are commonly used in Phase I clinical trials to identify the maximal tolerated dose(MTD) of a new drug. In this paper we review clinical examples of Phase I trials that were carried out in patients with refractory or relapsed leukemia and myelodysplastic syndrome. The recently proposed 3+1+1 design and rolling-6 design can shorten the trial duration, when a very slow accrual of patients with a simple 3+3 standard design may result in the untimely termination of trials. Too conservative approaches in determining the dose levels in Phase I clinical trials can leave clinical investigators unable to accurately determine the MTD. When determining future patient doses, the designs that use a time-to-event CRM can cooperate late toxicities by accounting for the proportion of the observation period of each enrolled patient. With the CRM design, simulations under different scenarios during the trial are important in detecting the under- or over-estimation of the initial estimate of the dose-limiting toxicity rate for each dose level. We present the advantages and drawbacks of the designs used in Phase I clinical trials for leukemia patients.

• 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.

• The Journal of Korean Medicine
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• 제44권2호
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• pp.70-105
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• 2023

This study was conducted to examine the current status of traditional korean medicine studies on gastroesophageal reflux disease in Korea, identify deficiencies, and suggest the direction of future medicine research methods to lay the foundation for traditional korean medicine treatment. All domestic papers on the korean traditional treatment of gastroesophageal reflux disease were selected among the literature published until August 2022 in six domestic databases. A total of 52 selected research data were classified into experimental research papers, clinical research papers, and review papers. In experimental papers, to evaluate the effectiveness of treatment, improvement of esophageal mucosal lesions, anti-inflammatory mechanisms, antioxidant mechanisms, esophageal mucosal protection mechanisms, gastric peristalsis control, and gastric acid secretion inhibition mechanisms were used as evaluation measures. In the clinical research paper, the basis for diagnosis of cases was clinical symptoms through medical history listening and diagnosis through visits to hospitals in the past. The average treatment period was 40.7 days, and the duration of treatment was not significantly affected by the duration of the disease. The most widely used Korean medicine treatment intervention was herbal medicine. There were 3 literature review studies, 3 systematic literature review and meta-analysis studies, 1 comparative review study for clinical trial guideline development, all using Chinese papers. This study included all domestic papers on gastroesophageal reflux disease to identify the research trend of the Korean oriental medicine community, and based on this, it is meaningful to confirm areas that need to be supplemented in future research plans.

• Journal of the Korea Society of Computer and Information
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• 제15권1호
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• pp.23-30
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• 2010

With the advancement of information technology and increasing diversity in medical field, there are ongoing researches on ontology based intelligent medical system in Oriental medicine field. Intelligent diagnostic support system uses ontology to give a structure to complex medical knowledge and personal medical history so that we can make diagnosis more scientific, and provide better medical services. In this paper, we suggest an ontology that structuralize three knowledge types basic medical data, clinical trial data, and personal health information, which can be used as important information for individually tailored diagnosis. Especially in Oriental medicine diagnosis, both patient's symptoms of illness and physical constitution play a great role; it can lead to distinct diagnosis depending on their combination. Thus, it is much needed to have a diagnostic support system that uses personal health history and physical constitution along with basic medical data and clinical trial data in the field. In this paper, we implemented an Oriental medicine diagnostic support system that provides individualized diagnosis service to each patient by building an ontology on Oriental medicine focused on individual physical constitution and disease information.