• Journal of Korean Medical classics
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• v.23 no.4
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• pp.63-102
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• 2010

Purpose : To propose various types of clinical research which is feasible for botanical new drug (IND) development processes, and suggest essential steps to development of study protocol for IND. Methods : Literature-based discussions and one research group's experience is given regarding domestic act, regulation, and system. Results : In order to get an approval of IND for botanical drug in Korea there are several types of clinical research to conduct. In quality control steps for standardized medicinal herbs, case reports or case series can be conducted, and for good manufacturing practice(GMP) steps, we can conduct case reports, case series, and retrospective cohort studies. In addition, as long as we gathered good laboratory practice(GLP) data we can conduct up to quasi-experimental studies and clinical trials including investigator initiated trials. In order to conduct these studies development of study protocol is essential. First, we obtain historical evidence including target disease and indication, efficacy, safety, and endpoints by reviewing medical classics. Second, we obtain clinically and statistically important data by conducting non-clinical studies, observation studies, and quasi-experimental studies. Third, we generate research hypotheses and purposes and explore methodologies, endpoints, clinical practice guidelines, cost-effectiveness, and commercial potential. Finally, we develop study protocol with aid of biostatistician or expert in contract research organization. Discussions and conclusions : This study have obvious limitations in that most thoughts, suggestions, and proposes are from one research group's experience. Therefore, we hope to see various types of research in this topic and process from other research group as well.

• Journal of The Korean Society of Clinical Toxicology
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• v.10 no.2
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• pp.80-85
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• 2012

Purpose: The aim of this study was to describe the epidemiologic characteristics of adult patients with carbon monoxide poisoning who presented to the emergency department in recent years. Methods: This was a retrospective cohort study on adult consecutive patients with carbon monoxide (CO) poisoning who presented to the emergency department of a tertiary care university-affiliated hospital from January 1, 2008 to December 31, 2011. Results: A total of 91 patients were included in this study; there were 56(61.5%) unintentional and 35(38.5%) intentional poisonings. For the unintentional CO poisonings, the principal sources of exposure to CO were fire (39.3%), charcoal (17.9%), briquette charcoal (7.1%), wood burning boiler (7.1%), gas boiler (5.4%), automobile heater (3.6%), briquette boiler (3.6%), firewood (3.6%), and other items (12.5%). For the intentional CO poisonings, the sources were ignition charcoal (60.0%), briquette (31.4%), charcoal (5.7%) and butane gas (2.9%). For the unintentional CO poisonings, the places of poisoning were the home (58.9%), workplace (10.7%), public accommodation (8.9%), tent (8.9%), automobile (3.6%) and parking place (1.8%). For the intentional CO poisonings, the places of poisoning were the home (77.1%), public accommodation (11.4%) and automobile (11.4%). The proportion of intentional CO poisonings among total poisonings has increased significantly in recent years; 0.0% in 2008, 3.3% in 2009, 5.5% in 2010, and 29.7% in 2011. Conclusion: This study showed that in recent years in Korea, the source of CO has diversified broadly and intentional CO poisonings from burning ignition charcoal or briquettes has increased. Prevention efforts should consider these factors.

• Journal of Preventive Medicine and Public Health
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• v.38 no.2
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• pp.203-207
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• 2005

Objectives: Recently, the American Diabetes Association (ADA) redefined the criteria of prediabetes, which has lowered the diagnostic level of fasting plasma glucose (FPG) from 110 to 125 mg/dl, down to levels between 100 to 125mg/dl. The purpose of this study was to determine the predictive cutoff level of FPG as a risk for the development of diabetes mellitus in Korean men. Methods: A retrospective cohort study was conducted on 11,423 (64.5%) out of 17,696 males $\leq$30 years of age, and who met the FPG of $\leq$125 mg/dl and hemoglobin A1c of $\leq$ 6.4% criteria, without a history of diabetes, and who were enrolled at the screening center of a certain university hospital between January and December 1999. The subjects were followed from January 1999 to December 2002 (mean follow-up duration; 2.3(${\pm}0.7$) years). They were classified as normal (FPG <100mg/dl), high glucose (FPG $\geq$100mg/dl and <110mg/dl) and impaired fasting glucose (FPG $\geq$110mg/dl and $\leq$125mg/dl) on the basis of their fasting plasma glucose level measured in 1999. We compared the incidence of diabetes between the 3 groups by performing Cox proportional hazards model and used receiver operating characteristic analyses of the FPG level, in order to estimate the optimal cut-off values as predictors of incident diabetes. Results: At the baseline, most of the study subjects were in age in their 30s to 40s (mean age, 41.8(${\pm}7.1$) year). The incidence of diabetes mellitus in this study was 1.19 per 1,000 person-years (95% CI=0.68-1.79), which was much lower than the results of a community-based study that was 5.01 per 1,000 person-years. The relative risks of incident diabetes in the high glucose and impaired fasting glucose groups, compared with the normal glucose group, were 10.3 (95% CI=2.58-41.2) and 95.2 (95% CI= 29.3-309.1), respectively. After adjustment for age, body mass index, and log triglyceride, a FPG greater than 100mg/dl remained significant predictors of incident diabetes. Using the receiver operating characteristic (ROC) curve, the optimal cutoff level of FPG as a predictor of incident diabetes was 97.5 mg/dl, with a sensitivity and a specificity of 81.0% and 86.0%, respectively. Conclusion: These results suggest that lowering the criteria of impaired fasting glucose is needed in Korean male adults. Future studies on community-based populations, including women, will be required to determine the optimal cutoff level of FPG as a predictor of incident diabetes.

• Tuberculosis and Respiratory Diseases
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• v.46 no.1
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• pp.25-35
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• 1999

Background : The treatment for multi-drug resistant tuberculosis(MDRTB) is encountered to be important clinically, but there are still a few reports about it all over the world. So, we evaluated the outcomes of only chemotherapy for the pulmonary MDRTB retrospectively. Method: We reviewed the clinical courses of 63 patients with pulmonary disease due to M.tuberculosis resistant to rifampin and isoniazid who were under follow-up between March 1996 and June 1996 after hospitalization at our hospital between January 1993 and January 1996. We performed cohort retrospective study for all these patient's records. Their regimens were selected individually and preferably included four medications that they had not been given previously and to which the strain was fully susceptible. Results: The 63 patients(mean age, 43.2 years) had previously received a median 5.1drugs. Fifty two(82.5%) patients responded to chemotherapy(as indicated by negative sputum cultures for at least three consecutive months) ; eleven patients(17.5 %) had no response, as shown by continually positive cultures. In a univariate analysis, an unfavorable response was significantly associated with greater number of resistant drugs before the current courses of therapy(relative risk 21.5 ; 95 percent confidence interval, 1.2-3.0; p<0.05). The mean period of follow-up was seventeen months. There was no relapse suooequently among the patients with responses. There was no death related to tuberculosis. Conclusion: In this report from National Masan Tuberculosis Hospital in Korea, multi-drug resistant pulmonary tuberculosis responded relatively well to carefully selected regimens.

• Journal of Trauma and Injury
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• v.36 no.4
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• pp.362-368
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• 2023

Purpose: Clinical reports on treatment outcomes of sternal fractures are lacking. This study details the clinical features, treatment approaches, and outcomes related to traumatic sternal fractures over a 10-year period at a single institution. Methods: A retrospective cohort study was conducted of patients admitted to a regional trauma center between January 2012 and December 2021. Among 7,918 patients with chest injuries, 266 were diagnosed with traumatic sternal fractures. Patient data were collected, including demographics, injury mechanisms, severity, associated injuries, sternal fracture characteristics, hospital stay duration, mortality, respiratory complications, and surgical details. Surgical indications encompassed emergency cases involving intrathoracic injuries, unstable fractures, severe dislocations, flail chest, malunion, and persistent high-grade pain. Results: Of 266 patients with traumatic sternal fractures, 260 were included; 98 underwent surgical treatment for sternal fractures, while 162 were managed conservatively. Surgical indications ranged from intrathoracic organ or blood vessel injuries necessitating thoracotomy to unstable fractures with severe dislocations. Factors influencing surgical treatment included flail motion and rib fracture. The median length of intensive care unit stay was 5.4 days (interquartile range [IQR], 1.5-18.0 days) for the nonsurgery group and 8.6 days (IQR, 3.3-23.6 days) for the surgery group. The median length of hospital stay was 20.9 days (IQR, 9.3-48.3 days) for the nonsurgery group and 27.5 days (IQR, 17.0 to 58.0 days) for the surgery group. The between-group differences were not statistically significant. Surgical interventions were successful, with stable bone union and minimal complications. Flail motion in the presence of rib fracture was a crucial consideration for surgical intervention. Conclusions: Surgical treatment recommendations for sternal fractures vary based on flail chest presence, displacement degree, and rib fracture. Surgery is recommended for patients with offset-type sternal fractures with rib and segmental sternal fractures. Surgical intervention led to stable bone union and minimal complications.

• Journal of Korean Neurosurgical Society
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• v.66 no.6
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• pp.726-734
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• 2023

Objective : Chronic subdural hematoma (CSDH) patients using antithrombotic agents (AT) at high risk for cardiovascular disease are increasing. The authors aimed to analyze the factors influencing outcome by targeting patients using AT and to establish a desirable treatment strategy. Methods : A retrospective analysis was performed on data from 462 patients who underwent burr hole trephination (BHT) surgery for CSDH at five hospitals from March 2010 to June 2021. Outcomes included incidence of postoperative acute bleeding, recurrence rate, and morbidity or mortality rate. Patients were divided into the following four groups based on their history of AT use : no AT. Only antiplatelet agents (AP), only anticoagulants (AC), both of AP and AC. In addition, a concurrent literature review was conducted alongside our cohort study. Results : Of 462 patients, 119 (119/462, 25.76%) were using AT. AP prescription did not significantly delay surgery (p=0.318), but AC prescription led to a significant increase in the time interval from admission to operation (p=0.048). After BHT, AP or AC intake significantly increased the period required for an in-dwelling drain (p=0.026 and p=0.037). The use of AC was significantly related to acute bleeding (p=0.044), while the use of AP was not (p=0.808). Use of AP or AC had no significant effect on CSDH recurrence (p=0.517 and p=1.000) or reoperation (p=0.924 and p=1.000). Morbidity was not statistically correlated with use of either AP or AC (p=0.795 and p=0.557, respectively), and there was no significant correlation with mortality for use of these medications (p=0.470 and p=1.000). Conclusion : Elderly CSDH patients may benefit from maintenance of AT therapy during BHT due to reduced thromboembolic risk. However, the use of AC necessitates individualized due to potential postoperative bleeding. Careful post-operative monitoring could mitigate prognosis and recurrence impacts.

• Korean Journal of Radiology
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• v.23 no.8
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• pp.828-834
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• 2022

Objective: This study aimed to assess the outcomes of outpatient day-care management of unruptured intracranial aneurysm (UIA), and to present the risks associated with different management strategies by comparing the outcomes and adverse events between outpatient day-care management and management with longer admission periods. Materials and Methods: This retrospective cohort study used prospectively registered data and was approved by a local institutional review board. We enrolled 956 UIAs from 811 consecutive patients (mean age ± standard deviation, 57 ± 10.7 years; male:female = 247:564) from 2017 to 2020. We compared the outcomes after embolization among the different admission-length groups (1, 2, and ≥ 3 days). The outcomes included pre- and post-modified Rankin Scale (mRS) scores and rates of adverse events, cure, recurrence, and reprocedure. Events were defined as any cerebrovascular problems, including minor and major stroke, death, or hemorrhage. Results: The mean admission period was 2 days, and 175 patients (191 aneurysms), 551 patients (664 aneurysms), and 85 patients (101 aneurysms) were discharged on the day of the procedure, day 2, and day 3 or later, respectively. During the mean 17-month follow-up period (range 6-53 months; 2757 patient years), no change in post-mRS was observed compared to pre-mRS in 99.6% of patients. Cure was achieved in 95.6% patients; minimal recurrence that did not require re-procedure occurred in 3.5% patients, and re-procedure was required in 2.3% (22 of 956) patients due to progressive enlargement of the recurrent sac during follow up (mean 17 months, range, 6-53 months). There were eight adverse events (0.8%), including five cerebrovascular (two major stroke, two minor strokes and one transient ischemic stroke), and three non-cerebrovascular events. Statistical comparison between groups with different admission lengths (1, 2, and ≥ 3 days) revealed no difference in the outcomes. Conclusion: This study revealed no difference in outcomes and adverse events according to the admission period, and suggested that UIA could be managed by outpatient day-care embolization.

• Clinics in Shoulder and Elbow
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• v.26 no.4
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• pp.357-365
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• 2023

Background: The purpose of this study was to evaluate the effect of concomitant open distal clavicle excision (DCE) on postoperative clinical outcomes and incidence of acromial and scapular stress fractures (ASFs) in patients with symptomatic acromioclavicular joint osteoarthritis (ACJ OA) undergoing reverse total shoulder arthroplasty (RTSA). Methods: A single-surgeon retrospective cohort study was conducted including patients who underwent primary elective RTSA with or without DCE from 2015 to 2019 with a minimum 6-month follow-up period. Shoulder active range of motion (AROM) and visual analog scale (VAS) pain were recorded preoperatively and postoperatively. ASFs and other adverse events were identified using postoperative notes and/or radiographs. Characteristics and outcomes were compared between the RTSA and RTSA-DCE groups. Results: Forty-six RTSA patients (mean age, 67.9±8.7 years; 60.9% male; mean follow-up, 24.9±16.6 months) and 70 RTSA-DCE patients (mean age, 70.2±8.9 years; 20.0% male; mean follow-up, 22.7±12.9 months) were included. There were no significant intergroup differences in rates of ASF (RTSA, 0.0% vs. RTSA-DCE, 1.4%; P=1.00), stress reactions (RTSA, 8.7% vs. RTSA-DCE, 11.4%; P=0.76), reoperation, revision, or infection (all P>0.05), or in pre-to-postoperative reduction in VAS pain (P=0.17) at latest follow-up. However, the RTSA-DCE group had greater pre-to-postoperative improvement in flexion AROM (RTSA, 43.7°±38.5° vs. RTSA-DCE, 59.5°±33.4°; P=0.03) and internal rotation (IR) AROM (P=0.02) at latest follow-up. Conclusions: Concomitant DCE in RTSA improves shoulder flexion and IR AROM, alleviates shoulder pain, and does not increase the risk of ASFs. Level of evidence: III.

• Tuberculosis and Respiratory Diseases
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• v.87 no.2
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• pp.176-184
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• 2024

Background: Results of studies investigating the association between body mass index (BMI) and mortality in patients with coronavirus disease-2019 (COVID-19) have been conflicting. Methods: This multicenter, retrospective observational study, conducted between January 2020 and August 2021, evaluated the impact of obesity on outcomes in patients with severe COVID-19 in a Korean national cohort. A total of 1,114 patients were enrolled from 22 tertiary referral hospitals or university-affiliated hospitals, of whom 1,099 were included in the analysis, excluding 15 with unavailable height and weight information. The effect(s) of BMI on patients with severe COVID-19 were analyzed. Results: According to the World Health Organization BMI classification, 59 patients were underweight, 541 were normal, 389 were overweight, and 110 were obese. The overall 28-day mortality rate was 15.3%, and there was no significant difference according to BMI. Univariate Cox analysis revealed that BMI was associated with 28-day mortality (hazard ratio, 0.96; p=0.045), but not in the multivariate analysis. Additionally, patients were divided into two groups based on BMI ≥25 kg/m² and underwent propensity score matching analysis, in which the two groups exhibited no significant difference in mortality at 28 days. The median (interquartile range) clinical frailty scale score at discharge was higher in nonobese patients (3 [3 to 5] vs. 4 [3 to 6], p<0.001). The proportion of frail patients at discharge was significantly higher in the nonobese group (28.1% vs. 46.8%, p<0.001). Conclusion: The obesity paradox was not evident in this cohort of patients with severe COVID-19. However, functional outcomes at discharge were better in the obese group.

• Journal of Korean Academy of Nursing
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• v.50 no.3
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• pp.401-410
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• 2020

Purpose: This study was performed to identify the prevalence of menstrual disorders in Korean women based on body mass index (BMI) and lifestyle factors, by utilizing the Korean National Health Insurance Database. Methods: A retrospective observational study design was used for the secondary data analysis. Data of women aged 15 to 49 years who were diagnosed with menstrual disorders were extracted from The National Health Insurance Service-National Health Screening Cohort in Korea from 2009 to 2016. The age-standardized prevalence rate of menstrual disorders was calculated using SAS version 9.4, and a Chi-square test and Cochran-Armitage test were performed. Results: In total, 2,219,445 cases were extracted from the database. The prevalence of menstrual disorders significantly increased from 8.6% to 11.6% (Z=135.16, p for trend <.001) over the past eight years. In particular, it was higher in underweight women than in women with normal weight across all years (Z=-4.18~-14.72, p<.001). Moreover, statistically significant differences in the prevalence of menstrual disorders were found to be associated with drinking and smoking in all years and with physical activity levels in part (p<.05~.001). Conclusion: These findings present compelling evidence on the prevalence of menstrual disorders based on a national database. Since the prevalence of menstrual disorders has steadily increased and differs based on BMI and lifestyle factors, educational and clinical interventions are necessary to promote risk awareness and appropriate behavioral changes among Korean women.