• Communications for Statistical Applications and Methods
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• v.25 no.3
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• pp.321-328
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• 2018

In clinical trials with repeated measurements, the time-averaged difference (TAD) may provide a more powerful evaluation of treatment efficacy than the rate of changes over time when the treatment effect has rapid onset and repeated measurements continue across an extended period after a maximum effect is achieved (Overall and Doyle, Controlled Clinical Trials, 15, 100-123, 1994). The sample size formula has been investigated by many researchers for the evaluation of TAD in two treatment groups. For the evaluation of TAD in multi-arm trials, Zhang and Ahn (Computational Statistics & Data Analysis, 58, 283-291, 2013) and Lou et al. (Communications in Statistics-Theory and Methods, 46, 11204-11213, 2017b) developed the sample size formulas for continuous outcomes and count outcomes, respectively. In this paper, we derive a sample size formula to evaluate the TAD of the repeated binary outcomes in multi-arm trials using the generalized estimating equation approach. This proposed sample size formula accounts for various correlation structures and missing patterns (including a mixture of independent missing and monotone missing patterns) that are frequently encountered by practitioners in clinical trials. We conduct simulation studies to assess the performance of the proposed sample size formula under a wide range of design parameters. The results show that the empirical powers and the empirical Type I errors are close to nominal levels. We illustrate our proposed method using a clinical trial example.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.4
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• pp.193-206
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• 2008

Purpose: In spite of many arguments on the result of WHI (Women's Health Initiative) study, no one can deny the necessity for researches on the alternative treatment to HRT (hormone replacement therapy). In this study, the author wanted to investigate the method of precedent acupuncture RCTs (randomized controlled trials) to make out the appropriate acupuncture study design on postmenopausal and perimenopausal hot flashes in Korea. Methods: Precedent studies were investigated using Pubmed search and key-words "acupuncture and hot flash", "acupuncture and menopause", "acupuncture and vasomotor", limited to RCT, from 2000 to 2008 April. Results: As a result. 10 studies were searched. In the hereafter studies, multi-center clinical trials which consist of population group of postmenopausal and perimenopausal women that would be pre-stratified and more than 50 patients per treatment arm seem adequate. Sham control study can make out the proper consequence because many people are get used to acupuncture in Korea. Flexible choice of acupoints addressed an individual's symptoms using standardized algorithm is recommended. Treatment consist of 4 weeks' observation, 11 acupuncture sessions during 7 weeks, follow-up of 3 months or more after treatment and hot flash score as a primary outcome measure seem appropriate. After all, higher level of description according to global standard must be obtained in the study report and publishing. Conclusion: The researchers should develope the methodology of acupuncture clinical trial on the postmenopausal and perimenopausal hot flashes.

• Korean Journal of Acupuncture
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• v.34 no.3
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• pp.116-125
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• 2017

Objectives : The aim of this study was to assess the effectiveness of acupuncture in treating prehypertension and stage 1 hypertension in postmenopausal women. Methods : The study was a multi-center, four-arm, non-blinded, randomized clinical trial. Sixty participants were randomly assigned to experimental or control groups. The experimental groups received 10 acupuncture sessions over 4 weeks(Group A, n=20) or 20 sessions over 8 weeks(Group B, n=20) along with usual care. The acupoints were GB20, LI11, ST36, and SP6, bilaterally. The acupuncture groups were followed-up for an additional 12 weeks after acupuncture treatment. The control groups received usual care for 16 weeks(Group C, n=10) or 20 weeks(Group D, n=10). The outcomes were blood pressure, blood pressure control rates, lipid profile, and high-sensitivity C-reactive protein(hs-CRP). Results : After 4 weeks, DBP in the acupuncture groups(A+B) showed no significant decrease compared to the control group(C+D). However, after 8 weeks of acupuncture treatment, group B showed a significant decrease in DBP after acupuncture treatment and follow-up period compared to control group. Although there was no difference between the acupuncture and control groups in SBP after acupuncture treatment, group B showed a significant decrease in SBP compared to control group after follow-up period. Lipid profiles and hs-CRP did not differ significantly between acupuncture and control groups. Conclusions : Acupuncture treatment for 8 weeks showed the effect on prehypertension and mild hypertension. To verify the effect of acupuncture on blood pressure, rigorous trials including more participants are required.