• The Korean Journal of Applied Statistics
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• v.18 no.1
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• pp.159-171
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• 2005

The US Food and Drug Administration(FDA) recommends that population bioequivalence and individual bioequivalence would be assessed to address the prescribability and switchability between a brand-name drug and its new formulation or generic copy in its 2001 guidance document. The test for population bioequivalence in the latest FDA guidance is recommended in 2 x 4 crossover design, but it turns out to be very conservative. Recently Lee, Shao & Chow(2002), Chow, Shao & Wang(2003) and McNally, Iyer & Mathew(2002) proposed new statistical methods for assessing population bioequivalence between drugs to correct the biasness of current FDA method. Since 2 x 2 crossover experiment is most welcomed design in bioequivalence testing, we adopt their methods to 2 x 2 crossover designs and compare their methodologies with FDA one through the simulation study.

• Communications for Statistical Applications and Methods
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• v.11 no.2
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• pp.235-246
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• 2004

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1211-1218
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• 2008

Maximum likelihood estimator (MLE) and restricted maximum likelihood estimator (REMLE) approaches are available in analyzing the linear mixed model (LMM) like bioequivalence trials. US FDA (2001) guides that REMLE may be useful to assess bioequivalence (BE) test. This paper studies the statistical behaviors of the methods in assessing BE tests when some of observations are missing at random. The simulation results show that the REMLE maintains the given nominal level well and the MLE gives a bit higher power. Considering the levels and the powers, the REMLE approach is recommended when the sample sizes are small to moderate and the MLE approach should be used when the sample size is greater than 30.

• The Korean Journal of Applied Statistics
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• v.23 no.1
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• pp.139-150
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• 2010

In recent years, more generic drug products became available. The current regulation for assessing the bioequivalence of two drug formulations is based on the concept of average bioequivalence. This approach has been indicated to be insufficient for assessing switchability between two drug formulations and US FDA has adopted individual bioequivalence as one of the bioequivalence criterion since 2001. The US FDA recommends that individual bioequivalence be assessed based on $2\;{\times}\;4$ crossover design, while a $2\;{\times}\;3$ crossover design may be used as an alternative design to reduce the length and cost of the study. In this paper, a statistical procedure for assessment of individual bioequivalence under $3\;{\times}\;2$ crossover designs is proposed and some statistical points are discussed with $2\;{\times}\;3$ crossover design and $2\;{\times}\;3$ extra-reference design through simulation studies.

• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.107-113
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• 2016

In this paper, we suggest a design method of a wide-band Butler matrix working at 5.9 GHz for V2X communication antennas. Since V2X communication needs beam-forming and beam-steering antennas to make transportation systems, mobile comm platforms, saturated frequency-resources, and signal TX-and-RX smart, multi-functional, resolved, and efficient utmost, respectively, the proper Butler matrix and its radiating elements as a low-profile geometry are realized. The constitutive components of the basic Butler matrix of a narrow band are designed first. And then, it is extended to a wide-band version to make its frequency-shift less affected by the event of the antenna system being mounted on a car body. The beam-forming and beam-steering performance is presented as the common feature tagged along with the different bandwidths of the frequency responses as the comparison between the narrow- and wide-band cases.

• Communications for Statistical Applications and Methods
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• v.16 no.5
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• pp.745-751
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• 2009

Outlying or extreme observations are defined to be subject data for which one or more bioavailability measures are discordant with corresponding data for that subject and/or for the rest of the subjects in a study. The presence of outlying observations can have very serious consequences on the conclusions resulting from a bioequivalence study. Two statistical methods are proposed by generalizing the current well known methods and an illustrated example is presented with discussion.

• Korean Parent-Child Health Journal
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• v.13 no.2
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• pp.78-85
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• 2010

Purpose: The purpose of this study was to examine the pain reducing effects of the dextrose-coated pacifier on venipuncture in premature infants. Methods: The design of this study is a nonequivalent control group pretest-posttest design and a crossover trial. The analysed cases were 40 premature infants (20 in experimental group and 20 in control group) in neonatal intensive care unit of a University Hospital, Gyeongnam Province, Korea. The data were collected from April to October, 2009. The experimental treatment was carried out nursing 20% dextrose-coated pacifier on venipuncture for IV injection. The instruments were $O_2$ saturation and heart rate on pulse oxymeter monitor to measure physiologic pain responses, and NIPS to measure behavioral pain responses. Collected data were analyzed with $x_2$ test, t-test using SPSS program. Results: The effects of the 20% dextrose-coated pacifier were found in the physiologic (only heart rate) and behavioral pain response on venipuncture. Conclusion: These finding is suggested that the dextrose-coated pacifier could be an effective nursing intervention for reducing pain on venipuncture in premature infants.

• Physical Therapy Rehabilitation Science
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• v.12 no.3
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• pp.320-326
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• 2023

Objective: The purpose of this study is to investigate the impact of visual biofeedback methods utilizing pressure sensors on the static balance of stroke patients. Design: Randomized crossover study. Methods: A total of 27 patients with hemiparesis participated in this study. The following three feedback conditions were considered: condition 1 (Knowledge of performance feedback), condition 2 (Knowledge of result feedback), and condition 3 (None feedback). A force plate was used to measure static balance. The total sway length, average sway velocity, x-axis excursion, and y-axis excursion of the center of pressure were measured. One-way repeated-measures analysis of variance was employed for comparisons of variables between each condition. The statistical significance level was set at α = 0.05 for all analyses. Results: There was a significant difference in the static balance results between each feedback condition (p<0.05). In the post-hoc results, it was confirmed that the static balance was significant in the order of knowledge of performance feedback, knowledge of result feedback, and none feedback. Conclusions: When comparing the three conditions, it was observed that knowledge of performance feedback showed the most improved effect on static balance ability. As further research progresses, that this approach could be used as an effective intervention method in clinical settings.

• Journal of Pharmaceutical Investigation
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• v.36 no.3
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• pp.193-199
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• 2006

A bioequivalence study of $Sudo^{TM}$ Ranitidine HCI tablet (Sudo Pharma. Ind. Co., Ltd.) to $Curan^{TM}$ tablet (Il Dong Pharma. Ind. Co., Ltd.) was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty four healthy male Korean volunteers received each medicine at the ranitidine hydrochloride dose of 150 mg in a 2x2 crossover study. There was a one week wash-out period between the doses. Plasma concentrations of ranitidine were monitored by a high-turbulent liquid chromatography (HTLC) for over a period of 12 hours after drug administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found far all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Sudo^{TM}$ Ranitidine $HCl/Curan^{TM}$ were 0.92-1.00 and 0.90-1.03, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the bioequivalence of $Sudo^{TM}$ Ranitidine HCI and $Curan^{TM}$ with respect to the rate and extent of absorption.