• Korean Journal of Acupuncture
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• v.35 no.2
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• pp.47-55
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• 2018

Objectives: Clinical improvements can be observed following placebo administrations in clinical trials. Randomized controlled trials have been conducted to disentangle the specific effects of therapeutic interventions over the past decade. In acupuncture trials, non-penetrating placebo needles offer the opportunity to determine the specific effects of needling. Methods: The present review provides an overview of the concept of the placebo effect and the characteristics of the placebo needles. Results: Placebo control can contribute to minimize for bias and the contextual and psychological components of therapeutic interventions. Placebo control should meet two criteria: blinding efficacy (indistinguishable from active treatment) and physiological inertness. In the case of acupuncture, however, it is difficult to meet both criteria simultaneously. The dilemma of placebo needles suggests that placebo needles do not constitute proper control in acupuncture research. Considering the characteristics of placebo needles, patients are more likely to perceive placebo needles as active treatment in acupuncture trials compared to placebo pills in pharmaceutical trials. Placebo response might be observed more frequently to placebo needles than to placebo pills. When acupuncture treatments are utilized in clinical use, placebo effects can be enhanced by exploiting patients' expectations in the contextual or environmental cues that surround medical intervention. Conclusions: We have to consider these unique characteristics of placebo needles in order to avoid drawing premature conclusions that acupuncture itself is just a placebo.

• The Korean Journal of Applied Statistics
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• v.25 no.4
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• pp.575-587
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• 2012

The effect of a new treatment is proven through the comparison of a new treatment with placebo; however, the number of parent non-inferiority trials tends to grow proportionally to the number of active controls. In a non-inferiority trial a new treatment is approved by proof that the new treatment is not inferior to an active control; however, both additional assumptions and historical trials are needed to show (through the comparison of the new treatment with the active control in a non-inferiority trial) that the new treatment is more efficacious than a putative placebo. The two different methods of using the historical data: frequentist principle method and meta-analytic method. This paper discusses the statistical methods and different Type I error rates obtained through the different methods employed.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.2
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• pp.94-101
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• 2008

Objectives : To discuss the types of control groups in randomized controlled trials (RCTs) of herbal medicine, and to provide suggestions for improving the design of control group in future clinical trials. Methods : We reviewed the 8 articles about clinical trial design of Chinese herbal preparation which were published from 2005 through 2008. We selected those articles from CNKI(中國知識基礎施設工程(http://www.cnki.net)). Results : It is necessary to have control group in randomized controlled trials(RCTs) of Korean herbal preparation. But there are problems in the selection of appropriate control group drug. This paper lists several problems about the choice of control drug and puts forward some proposals and countermeasures. There are problems such as ethics and manufacturing matching placebo and positive control herbal drug. Conclusion : To improve the quality of control group design, we introduce standard drug plus placebo drug method and add-on research for placebo control group design, double dummy technique, using negative control drug or composite control drug for active control group design.

• Clinical and Experimental Pediatrics
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• v.55 no.11
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• pp.403-407
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• 2012

Noninferiority trials test whether a new experimental treatment is not unacceptably less efficacious than an active control treatment already in use. With continuous improvements in health technologies, standard care, and clinical outcomes, the incremental benefits of newly developed treatments may be only marginal over existing treatments. Sometimes assigning patients to a placebo is unethical. In such circumstances, there has been increasing emphasis on the use of noninferiority trial designs. Noninferiority trials are more complex to design, conduct, and interpret than typical superiority trials. This paper reviews the concept of noninferiority trials and discusses some important issues related to them.

• Journal of Acupuncture Research
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• v.28 no.5
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• pp.29-38
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• 2011

Objectives : Recent well-designed randomized controlled trials(RCTs) and their meta-analysis have been published on the efficacy of acupuncture in different condition. In most of them, real acupuncture is compared with sham acupuncture including invasive and non-invasive sham methods. But it is not clear how active sham methods are. These results tend to lead the conclusion that acupuncture has no more effective than sham acupuncture. In order to investigate that sham acupuncture is appropriate as a control, we reviewed several acupuncture trials using different sham acupuncture as a control. Methods : We searched Cochrane researches of acupuncture, reviewed and analyzed 25 RCTs in 42 Cochrane reviews. And especially we compared the effect of acupuncture according to the type of sham acupuncture. Results : Invasive sham acupunctures are used in 12 RCTs and non-invasive types are used in the rest. The majority of studies(19 RCTs) fail to show effects beyond a sham acupuncture. Streitberger's sham needle is a validated sham acupuncture of non-invasive type that was used in 8 trials and also no significant group differences are shown except one trial. Conclusions : Acupuncture is a complex intervention. Clinical trials of acupuncture need to be reexamined and redesigned to remove several bias. Especially, sham acupuncture as a control might be investigated for physiological effects as well as validation test including patient-blinding and de qi sensation. Other research need to be investigated and developed for acupuncture trials.

• Korean Journal of Applied Biomechanics
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• v.32 no.4
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• pp.121-127
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• 2022

Objective: The purpose of this study was to investigate potential effects of transcranial direct current stimulation (tDCS) on bimanual force control capabilities in healthy young adults. Method: Eighteen right-handed healthy young adults (10 females and 8 males; age: 23.55 ± 3.56 yrs) participated in this crossover design study. All participants were randomly allocated to both active-tDCS and sham-tDCS conditions, respectively. While receiving 20 min of active- or sham-tDCS interventions, all participants performed bimanual isometric force control tasks at four submaximal targeted force levels (i.e., 5%, 10%, 15, and 20% of maximal voluntary contraction: MVC). To compare bimanual force control capabilities including force accuracy, variability, and regularity between active-tDCS and sham-tDCS conditions, we conducted two-way repeated measures ANOVAs (2 × 4; tDCS condition × Force levels). Results: We found no significant difference in baseline MVC between active-tDCS and sham-tDCS conditions. Moreover, our findings revealed that providing bilateral tDCS including anodal tDCS on left primary motor cortex (M1) and cathodal on right M1 while conducting bimanual force control trials significantly decreased force variability and regularity at 5%MVC. Conclusion: These findings suggest that providing bilateral tDCS on M1 areas may improve bimanual force control capabilities at a relatively low targeted force level.

• 대한예방의학회:학술대회논문집
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• 1994.02b
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• pp.270-284
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• 1994

Interim analyses of randomized trials enable investigators to make more efficient use of limited research resources and to satisfy ethical requirements that a regimen be discontinued as soon as it has been established to have an inferior efficacy/toxicity profile. Unfortunately. the integrity and credibility of these trials can be compromised if inappropriate procedures are used in monitoring interim data. 'In this paper we discuss how group sequential designs provide useful guidelines that enable one to satisfy the valid objectives of interim monitoring while avoiding undesirable consequences, and we consider how flexible one can be in the way such designs are implemented. We also provide motivation for the role of data-monitoring committees in preserving study integrity and credibility in either government- or industry-sponsored trials. In our view. these committees should have multidisciplinary representation and membership limited to individuals free of apparent significant conflict of interest, and ideally should be the only individuals to whom the data analysis center provides interim results on relative efficacy of treatment regimens. Finally. we discuss some important practical issues such as estimation following group sequential testing, anal ysis of secondary outcomes after using a group sequential design applied to a primary outcome, early stopping of negative trials. and the role of administrative analyses.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2073-2075
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• 2003

This paper presents the active vibration control of flexible cantilever beam using piezoceramic actuators. The transfer function from the force input to the bending displacement was obtained via modal analysis results and piezoelectric constitutive equations. For the active vibration control piezoceramic actuators and sensors were used to construct a flexible smart cantilever beam. To further enhance the sensing and actuation properties of the piezoceramics, a typical interdigitated electrode pattern was fabricated. The PID controller was designed via various simulation and experiment trials. It was shown that the PID controller could suppress vibration of the beam effectively. Simulations and experiments verified good performances of the designed controller.

• Journal of Pharmacopuncture
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• v.20 no.3
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• pp.179-193
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• 2017

Objectives: Nigella sativa (black seed or black cumin), which belongs to the Ranunculacea family, is an annual herb with many pharmacological properties. Among its many active constituents, thymoquinone (TQ) is the most abundant constituent of the volatile oil of Nigella sativa (N. sativa) seeds, and it is the constituent to which most properties of this herb are attributed. Methods: PubMed-Medline, Scopus, and Web of Science databases were searched to identify randomized control trials (RCTs) investigating the therapeutic effects of N. sativa and/or TQ. In this review, we investigated the clinical uses of N. sativa and TQ in the prevention and the treatment of different diseases and morbidity conditions in humans. Results: Black seed and TQ are shown to possess multiple useful effects for the treatment of patients with several diseases, such as inflammatory and auto-immune disorders, as well as metabolic syndrome. Also, other advantages, including antimicrobial, anti-nociceptive and anti-epileptic properties, have been documented. The side effects of this herbal medicine appear not to be serious, so it can be applied in clinical trials because of its many advantages. Conclusion: Some effects of N. sativa, such as its hypoglycemic, hypolipidemic and bronchodilatory effects, have been sufficiently studied and are sufficiently understood to allow for the next phase of clinical trials or drug developments. However, most of its other effects and applications require further clinical and animal studies.

• The Korean Journal of Applied Statistics
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• v.27 no.5
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• pp.833-842
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• 2014

Non-inferiority trials indicate whether the effect of an experimental treatment is not worse than an active control. Chen et al. (2006) and Kang (2010) proposed a test method for non-inferiority trials using confidence intervals. In this paper, we suggest a new nonparametric method using a confidence interval based on Wilcoxon rank-sum test and Hodges-Lehmann estimator of active control. A Monte-Carlo simulation study compares the type I error and the power of the proposed method with previous methods.