• The Journal of Korean Academy of Prosthodontics
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• v.45 no.3
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• pp.321-328
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• 2007

Statement of problem. To work the economic limitation of dental implant usage, some types of domestic implant have been developing. But, there have been seldom reported about the clinical success rate of them as yet. Purpose. The aim of this retrospective multicenter study was to evaluate the performance of CSM implants(CSM company, Daegu, Korea). Material and methods. Thirty-five patients were rehabilitated with 150 CSM implants in this multicenter study. Results. The success rate was 96.2%. CSM Titanium fixtures can obtain slightly higher success rate when a cover screw was not used for implant installation than when used. However it doesn't show significant difference(p=.7615, Fisher's Exact test). Conclusion. This multicenter retrospective study demonstrated the efficacy of the CSM implant in the treatment of variety of clinical manifestation of tooth loss. And it can be assumed that whether a cover screw is used or not should no influence on the osseointegration.

• The Korean journal of internal medicine
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• v.33 no.6
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• pp.1119-1128
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• 2018

Background/Aims: In multicenter clinical trials, laboratory tests are performed in the laboratory of each center, mostly using different measuring methodologies. The purpose of this study was to evaluate coefficients of variation (CVs) of laboratory results produced by various measuring methods and to determine whether mathematical data adjustment could achieve harmonization between the methods. Methods: We chose 10 clinical laboratories, including Green Cross Laboratories (GC Labs), the central laboratory, for the measurement of total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), serum triglycerides, creatinine, and glucose. The serum panels made with patient samples referred to GC Labs were sent to the other laboratories. Twenty serum samples for each analyte were prepared, sent frozen, and analyzed by each participating laboratory. Results: All methods used by participating laboratories for the six analytes had traceability by reference materials and methods. When the results from the nine laboratories were compared with those from GC Labs, the mean CVs for total cholesterol, HDL-C, LDL-C, and glucose analyzed using the same method were 1.7%, 3.7%, 4.3%, and 1.7%, respectively; and those for triglycerides and creatinine analyzed using two different methods were 4.5% and 4.48%, respectively. After adjusting data using Deming regression, the mean CV were 0.7%, 1.4%, 1.8%, 1.4%, 1.6%, and 0.8% for total cholesterol, HDL-C, LDL-C, triglyceride, creatinine, and glucose, respectively. Conclusions: We found that more comparable results can be produced by laboratory data harmonization using commutable samples. Therefore, harmonization efforts should be undertaken in multicenter trials for accurate data analysis (CRIS number; KCT0001235).

• The Journal of KAIRB
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• v.6 no.2
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• pp.38-47
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• 2024

Purpose: The purpose of this study is to compare the efficiency of 2 types of Institutional Review Boards (IRBs) for multicenter research. Methods: The 2 types are joint IRB and local IRB. For this study, we selected multicenter research reviewed and approved by joint or local IRBs between October 2019 and December 2022. We assessed the time it took for each IRB to approve the research based on the number of working days per IRB review case. We then stratified the data according to the number of participating institutions, the type of research, and the type of IRB review. Results: The results of our study show that joint IRB is more efficient than local IRB. The median IRB approval time for joint IRB was 27 days, 73.5% shorter than local IRB (27 days vs. 102 days, respectively, p<0.001). As the number of participating institutions in multicenter research increased, joint IRB reviews became more efficient regarding the required approval time than local IRB reviews. We also found that joint IRB was faster in every administrative step until new research was approved (p<0.005) when compared to local IRB. Conclusion: Our study highlights that a single review through a joint IRB can significantly reduce the time required for IRB approval of multicenter research. This approach can ensure that all participating institutions follow the same review results. Therefore, a single IRB review effectively reduces the burden of IRB for multicenter research.

• The Journal of Korean Obstetrics and Gynecology
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• v.23 no.1
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• pp.42-52
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• 2010

Purpose: This report aims to administer methodologic issues around recently conducted multicenter study for evaluating the effects of acupuncture on menopusal hot flashes and discuss practical issues for further implementation of acupuncture clinical trial for hot flashes. Methods: Study process were mentioned, and issues related to avoiding risk of bias, designing appropriate control group, optimal outcome measurement, potential different effects of menopausal status on study outcomes, and suggestions for developing future clinical trials are discussed. Results: Shortcomings of our multicenter study include lack of allocation concealment and assessor blinding, subjective outcome measurement, short-term follow-up, and fixed acupuncture regimen despite pragmatic purpose of this study. Improving trial design, using objective or validated outcomes, assessing long-term effects of acupuncture, and individualizing acupuncture regimen are needed in future clinical trials. Conclusion: We expect these practical discussions to enable researchers to plan and develop future well-designed clinical trials for evaluating the effects of acupuncture on hot flashes or other women's health issues.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.255-268
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• 2022

Objective : Chronic subdural hematoma (CSDH) is a common disease in neurosurgical departments, but optimal perioperative management guidelines have not yet been established. We aimed to assess the current clinical management and outcomes for CSDH patients and identify prognostic factors for CSDH recurrence. Methods : We enrolled a total of 293 consecutive patients with CSDH who underwent burr hole craniostomy at seven institutions in 2018. Clinical and surgery-related characteristics and surgical outcomes were analyzed. The cohort included 208 men and 85 women. Results : The median patient age was 75 years. Antithrombotic agents were prescribed to 105 patients. History of head trauma was identified in 59% of patients. Two hundred twenty-seven of 293 patients (77.5%) had unilateral hematoma and 46.1% had a homogenous hematoma type. About 70% of patients underwent surgery under general anesthesia, and 74.7% underwent a single burr hole craniostomy surgery. Recurrence requiring surgery was observed in 17 of 293 patients (5.8%), with a median of 32 days to recurrence. The postoperative complication rate was 4.1%. In multivariate analysis, factors associated with CSDH recurrence were separated hematoma type (odds ratio, 3.906; p=0.017) and patient who underwent surgery under general anesthesia had less recurrence (odds ratio, 0.277; p=0.017). Conclusion : This is the first retrospective multicenter generalized cohort pilot study in the Republic of Korea as a first step towards the development of Korean clinical practice guidelines for CSDH. The type of hematoma and anesthesia was associated with CSDH recurrence. Although the detailed surgical method differs depending on the institution, the surgical treatment of CSDH was effective. Further studies may establish appropriate management guidelines to minimize CSDH recurrence.

• Journal of Sasang Constitutional Medicine
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• v.24 no.2
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• pp.47-53
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• 2012

1. Objectives : The aim of the present study was to describe the Korea Constitutional Multicenter Bank (KCMB), which was various clinical data bank for scientific advancement of constitutional diagnosis and treatment. 2. Methods and Results : The KCMB is based on the 28 multi-institute cooperative clinical research networks including domestic and international institute. Since the KCMB was founded in 2006, data have been accumulated from 10,412 subjects. The KCMB consists of three parts: The clinical constitutional data, the measurement data, and the biological data. The method of data entry is via web based electronic Case Report From (eCRF). The eCRF has been developed and programed to ensure the efficient entry of data. We also developed coding manual, ongoing quality control assessment to obtain high-quality data. 3. Conclusions : The KCMB with various data contribute to providing the scientification of Sasang Constitutional Medicine.

• Clinical and Experimental Pediatrics
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• v.50 no.7
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• pp.601-605
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• 2007

The cure rate of acute lymphoblastic leukemia (ALL) in children dramatically improved over past 5 decades from zero to about 80%. The main cause of improvement is owing to the development of chemotherapy by multicenter clinical trial of large study groups with the understanding of leukemia biology. Recently, pediatric ALL protocols were applied to the treatment of adolescent and even adult ALL patients. For nearly 30 years, clinical factors have been used to risk-stratify therapy for children with ALL, so that the most intensive therapies are reserved for those patients at the highest risk of relapse. The risk groups of ALL are divided as standard- (low- plus intermediate-), high- and very high-risk group according to the prognostic factors, and treatment results improved by this risk based treatment. The factors used to risk-stratify therapy include age, gender, presenting leukocyte count, immunophenotype, cytogenetic aberrations including ploidy and translocations, and initial response after 1 to 2 weeks of therapy. But treatment efficacy is the most important determinant and can abolish the clinical significance of most, if at all, prognostic factors. Today, in the era of intensive, multiagent regimens, there is increasing evidence that we have reached the limits of prognostic significance of currently applied clinical risk factors in childhood ALL. As the cure rate of ALL is about 80%, introducing new prognostic factors such as new molecular prognostic markers, new methods of assessment about minimal residual disease, and pharmacogenetic study, with the development of stem cell transplantation and molecular targeted therapy are needed to cure residual 20% of childhood ALL patients without short and long term complications.

• Clinical Endoscopy
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• v.57 no.5
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• pp.620-627
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• 2024

Background/Aims: Few multicenter studies have investigated the efficacy of hemostatic powders in gastrointestinal (GI) bleeding. We aimed to investigate the clinical outcomes of hemostatic powder therapy and the independent factors affecting rebleeding rates. Methods: We retrospectively recruited patients who underwent a new hemostatic adhesive powder (UI-EWD; Next-Biomedical) treatment for upper and lower GI bleeding between January 1, 2020 and March 1, 2023. We collected patients' medical records and bleeding lesions. The primary outcomes were clinical and technical success rates, and the secondary outcomes were early and delayed bleeding rates refractory bleeding rate, mortality rate, and factors affecting early rebleeding rates. Results: This study enrolled 135 patients (age: 67.7±13.6 years, male: 74.1%) from five hospitals. Indications for UI-EWD were peptic ulcers (51.1%), post-procedure-related bleeding (23.0%), and tumor bleeding (19.3%). The clinical and technical success rates were both 97%. The early, delayed, and refractory rebleeding rates were 19.3%, 11.1%, and 12.8%, respectively. Initially elevated blood urea nitrogen (BUN) levels (p=0.014) and Forrest classification IA or IB compared with IIA or IIB (p=0.036) were factors affecting early rebleeding. Conclusions: UI-EWD showed high clinical and technical success rates; however, rebleeding after UI-EWD therapy in patients with initially high BUN levels and active bleeding, according to the Forrest classification, should be considered.

• Clinical Endoscopy
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• v.57 no.3
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• pp.375-383
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• 2024

Background/Aims: Endoscopic self-expandable metal stent (SEMS) placement is currently the standard technique for treating unresectable malignant distal biliary obstructions (MDBO). Therefore, covered SEMS with longer stent patency and fewer migrations are required. This study aimed to assess the clinical performance of a novel, fully covered SEMS for unresectable MDBO. Methods: This was a multicenter single-arm prospective study. The primary outcome was a non-obstruction rate at 6 months. The secondary outcomes were overall survival (OS), recurrent biliary obstruction (RBO), time to RBO (TRBO), technical and clinical success, and adverse events. Results: A total of 73 patients were enrolled in this study. The non-obstruction rate at 6 months was 61%. The median OS and TRBO were 233 and 216 days, respectively. The technical and clinical success rates were 100% and 97%, respectively. Furthermore, the rate of occurrence of RBO and adverse events was 49% and 21%, respectively. The length of bile duct stenosis (<2.2 cm) was the only significant risk factor for stent migration. Conclusions: The non-obstruction rate of a novel fully covered SEMS for MDBO is comparable to that reported earlier but shorter than expected. Short bile duct stenosis is a significant risk factor for stent migration.

• Korean Circulation Journal
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• v.54 no.6
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• pp.339-350
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• 2024

Background and Objectives: Ultimaster^TM, a third-generation sirolimus-eluting stent using biodegradable polymer, has been introduced to overcome long term adverse vascular events, such as restenosis or stent thrombosis. In the present study, we aimed to evaluate the 12-month clinical outcomes of Ultimaster^TM stents in Korean patients with coronary artery disease. Methods: This study is a multicenter, prospective, observational registry across 12 hospitals. To reflect real-world clinical evidence, non-selective subtypes of patients and lesions were included in this study. The study end point was target lesion failure (TLF) (the composite of cardiac death, target vessel myocardial infarction [MI], and target lesion revascularization [TLR]) at 12-month clinical follow up. Results: A total of 576 patients were enrolled between November 2016 and May 2021. Most of the patients were male (76.5%), with a mean age of 66.0±11.2 years. Among the included patients, 40.1% had diabetes mellitus (DM) and 67.9% had acute coronary syndrome (ACS). At 12 months, the incidence of TLF was 4.1%. The incidence of cardiac death was 1.5%, MI was 1.0%, TLR was 2.7%, and stent thrombosis was 0.6%. In subgroup analysis based on the presence of ACS, DM, hypertension, dyslipidemia, or bifurcation, there were no major differences in the incidence of the primary endpoint. Conclusions: The present registry shows that Ultimaster^TM stent is safe and effective for routine real-world clinical practice in non-selective Korean patients, having a low rate of adverse events at least up to 12 months.