• Communications for Statistical Applications and Methods
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• v.30 no.3
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• pp.245-258
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• 2023

This study proposes a modification to the objective function of the support vector machine for the linearly non-separable case of a binary classifier y_i ∈ {-1, 1}. The modification takes into account the position of each data item x_i from its corresponding class centroid. The resulting optimization function involves the centroid mean vector, and the spread of data besides the support vectors, which should be minimized by the choice of hyper-plane β. Theoretical assumptions have been tested to derive an optimal separable hyperplane that yields the minimal misclassification rate. The proposed method has been evaluated using simulation studies and real-life COVID-19 patient outcome hospitalization data. Results show that the proposed method performs better than the classical linear SVM classifier as the sample size increases and is preferred in the presence of correlations among predictors as well as among extreme values.

• Clinical and Experimental Pediatrics
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• v.63 no.7
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• pp.272-277
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• 2020

Background: The optimal management of perianal abscess in children is controversial. Purpose: To evaluate the efficiency of conservative treatment of perianal abscess in children and identify parameters that predict therapy failure. Methods: All cases of children younger than 14 years of age with perianal abscesses between 2001-2016 were evaluated. Results: Of the 113 enrolled patients, 64 underwent subsequent surgery for advanced disease (primary surgery group). Conservative treatment was initiated in 49 patients (primary conservative group) but was stopped because of inefficiency in 25 patients, who were referred for surgery after a median 7.03 days (range, 2 to 16 days). The other 24 patients (48%) initially achieved complete remission after conservative treatment, but 10 were readmitted after a median 34 months (range, 3 to 145 months) with recurrent disease. There were no significant differences in permanent success after conservative treatment between infants (10 of 29, 34%) and older children (4 of 20 [20%], P=0.122). Overall, conservative treatment alone was effective in only 14 of 113 patients. Recurrence after surgery occurred in 16 patients (25%) in the primary surgery group and 11 patients (22%) in the primary conservative group (P=0.75). Univariate analysis of predictors for conservative treatment failure revealed inflammatory values (C-reactive protein and white blood count, P=0.017) and abscess size (P=0.001) as significant parameters, whereas multivariate analysis demonstrated that only abscess size (odds ratio, 3.37; P=0.023) was significant. Conclusion: Conservative treatment of perianal abscess is permanently efficient in only a minority of children but is not associated with a higher recurrence rate after subsequent surgery. Abscess size is a predictor for therapy failure.

• Journal of Korean Neurosurgical Society
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• v.58 no.2
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• pp.93-100
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• 2015

Objective : Optimal treatment decision and estimation of the prognosis in traumatic brain injury (TBI) is currently based on demographic and clinical predictors. But sometimes, there are limitations in these factors. In this study, we analyzed three central nervous system biomarkers in TBI patients, will discuss the roles and clinical applications of biomarkers in TBI. Methods : From July on 2013 to August on 2014, a total of 45 patients were included. The serum was obtained at the time of hospital admission, and biomarkers were extracted with centrifugal process. It was analyzed for the level of S-100 beta (S100B), glial fibrillary acidic protein (GFAP), and ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1). Results : This study included 33 males and 12 females with a mean age of 58.5 (19-84) years. TBI patients were classified into two groups. Group A was severe TBI with Glasgow Coma Scale (GCS) score 3-5 and Group B was mild TBI with GCS score 13-15. The median serum concentration of S100B, GFAP, and UCH-L1 in severe TBI were raised 5.1 fold, 5.5 fold, and 439.1 fold compared to mild injury, respectively. The serum levels of these markers correlated significantly with the injury severity and clinical outcome (p<0.001). Increased level of markers was strongly predicted poor outcomes. Conclusion : S100B, GFAP, and UCH-L1 serum level of were significantly increased in TBI according to severity and associated clinical outcomes. Biomarkers have potential utility as diagnostic, prognostic, and therapeutic adjuncts in the setting of TBI.

• Journal of Korean Academy of Nursing
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• v.42 no.7
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• pp.1039-1049
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• 2012

Purpose: From the holistic environmental perspective, individual and environmental influences on low-income children's questionable development were identified and examined as to differences in the influences according to the child's developmental stage of infancy (age 0-35 months) or early childhood (age 36-71 months). Methods: This study was a cross-sectional comparative design using negative binominal regression analysis to identify predictors of questionable development separately for each developmental stage. The sample was comprised of 952 children (357 in infancy and 495 in early childhood) from low-income families in South Korea. Predictors included individual factors: child's age and gender; proximal environmental influences: family factors (family health conditions, primary caregiver, child-caregiver relationship, depression in primary caregiver) and institution factors (daycare enrollment, days per week in daycare); and distal environmental influences: income/resources factors (family income, personal resources and social resources); and community factors (perceived child-rearing environment). The outcome variable was questionable development. Results: Significant contributors to questionable development in the infancy group were age, family health conditions, and personal resources; in the early childhood group, significant contributors were gender, family health conditions, grandparent as a primary caregiver, child-caregiver relationships, daycare enrollment, and personal resources. Conclusion: Factors influencing children's questionable development may vary by developmental stage. It is important to consider differences in individual and environmental influences when developing targeted interventions to ensure that children attain their optimal developmental goals at each developmental stage. Understanding this may lead nursing professionals to design more effective preventive interventions for low-income children.

• Child Studies in Asia-Pacific Contexts
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• v.4 no.1
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• pp.27-45
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• 2014

The present study investigated the developmental pattern of Korean mothers' depressive symptoms from a week prior to birth through four months postpartum in a nationally represented survey sample in Korea, using a Latent Growth Curve model. Mother-reported four factors-maternal self-efficacy in parenting, father's participation in childcare, a number of hours mothers worked per week, child's emotional temperament-were examined as the predictors of depressive symptoms over time in the context of Korean culture. Effects of maternal depressive trajectories on their infants' developmental outcomes at the first year were also examined. Findings were as follows: First, mothers' reports of depressive symptoms decreased at the first month after birth and then increased again during the first 4 months postpartum. Second, mothers' perceived low spousal involvement in childcare, low parental self-efficacy, and their infants' difficult temperament at four-month old had significantly positive relations to the initial level of maternal depressive symptoms whereas the low spousal involvement in childcare and low maternal self-efficacy factors significantly predicted the changes of trajectories of maternal depressive symptoms. Third, the trajectories, in turn, predicted warm and responsive maternal parenting style at the fourth month. Subsequently, the parenting style had a significant longitudinal impact on the development of children's communication, problem-solving, and personal-social abilities. Based on these findings, awareness, preventive and interventional programs might be built to facilitate Korean mothers suffering severe postpartum depressive symptoms and further promote optimal early development of Korean children.

• Korean Journal of Community Nutrition
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• v.11 no.6
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• pp.779-784
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• 2006

Several studies about hospital malnutrition have been reported that about more than 40% of hospitalized patients are having nutritional risk factors and hospital malnutrition presents a high prevalence. People in a more severe nutritional status ended up with a longer length of hospital stay and higher hospital cost. Nutrition screening tools identify individuals who are malnourished or at risk of becoming malnourished and who may benefit from nutritional support. For the early detection and treatment of malnourished hospital patients , few valid screening instruments fur Koreans exist. Therefore, the aim of this study was to develop a simple, reliable and valid malnutrition screening tool that could be used at hospital admission to identify adult patients at risk of malnutrition using medical electrical record data. Two hundred and one patients of the university affiliated medical center were assessed on nutritional status and classified as well nourished, moderately or severely malnourished by a Patient-Generated subjective global assessment (PG-SGA) being chosen as the 'gold standard' for defining malnutrition. The combination of nutrition screening questions with the highest sensitivity and specificity at prediction PG-SGA was termed the nutrition screening index (NSI). Odd ratio, and binary logistic regression were used to predict the best nutritional status predictors. Based on regression coefficient score, albumin less than 3.5 g/dl, body mass index (BMI) less than $18.5kg/m^2$, total lymphocyte count less than 900 and age over 65 were determined as the best set of NSI. By using best nutritional predictors receiver operating characteristic curve with the area under the curve, sensitivity and 1-specificity were analyzed to determine the best optimal cut-off point to decide normal or abnormal in nutritional status. Therefore simple and beneficial NSI was developed for identifying patients with severe malnutrition. Using NSI, nutritional information of the severe malnutrition patient should be shared with physicians and they should be cared for by clinical dietitians to improve their nutritional status.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.4
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• pp.394-402
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• 2023

Backgrounds/Aims: Acute pancreatitis is an emergency presentation, which can range from mild to life threatening. Intravenous fluids are the cornerstone of management. Although the WATERFALL trial described the optimal fluid rate in mild/moderate pancreatitis, this trial excluded patients with moderate-severe/severe pancreatitis. The aim of this study was to establish clinical practice regarding intravenous fluid administration in acute pancreatitis and assess its effect on mortality. Methods: Prospective multi-centre audit of patients with acute pancreatitis was conducted. Data were collected regarding intravenous fluid administration within 72 hours of admission. The primary outcome was 30-day mortality. Multivariable logistic regression was used to identify predictors of 30-day mortality. Results: Those with severe pancreatitis received more fluid; median 5.7 L versus 4 L in 72 hours (p = 0.003). Participants with severe pancreatitis who died within 30 days received a median of 2,750 mL in the first 24 hours, compared to 4,000 mL in those who survived. The following factors were significant predictors of 30-day mortality: age, Glasgow score, C-reactive protein, ischaemic heart disease, and pancreatitis aetiology. Overall, volume of intravenous fluid was not associated with mortality. However, the effect of intravenous fluid volume on mortality differed significantly depending on pancreatitis severity. In severe pancreatitis, increased volume of intravenous fluid was associated with significant reductions in mortality (odds ratio = 0.655; 0.459-0.936; p = 0.020). Conclusions: In severe pancreatitis, more aggressive fluid prescription was associated with decreased mortality; however, this was not the case in milder disease. Further prospective trials guiding fluid resuscitation in severe pancreatitis are needed, as the impact of fluid on this population appears to differ from that in those with milder disease.

• Journal of Gastric Cancer
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• v.17 no.4
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• pp.319-330
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• 2017

Introduction: The extent of lymphadenectomy in the surgical treatment of gastric cancer is a topic of controversy among surgeons. This study was conducted to analyze the American National Cancer Database (NCDB) and conclude the optimal extent of lymphadenectomy for gastric adenocarcinoma. Methods: The NCDB for gastric cancer was utilized. Patients who received at least a partial gastrectomy were included. Patients with metastatic disease, unknown TNM stages, R1/R2 resection, or treated with a palliative intent were excluded. Joinpoint regression was used to identify the extent of lymphadenectomy that reflects the optimal survival. Cox regression analysis and Bayesian information criterion were used to identify significant survival predictors. Kaplan-Meier was applied to study overall survival and stage migration. Results: 40,281 patients of 168,377 met the inclusion criteria. Joinpoint analysis showed that dissection of 29 nodes provides the optimal median survival for the overall population. Regression analysis reported the cutoff ${\geq}29$ to have a better fit in the prognostic model than that of ${\geq}15$. Dissection of ${\geq}29$ nodes in the higher stages provides a comparable overall survival to the immediately lower stage. Nonetheless, the retrieval of ${\geq}15$ nodes proved to be adequate for staging without a significant stage migration compared to ${\geq}29$ nodes. Conclusion: The extent of lymphadenectomy in gastric adenocarcinoma is a marker of improved resection which reflects in a longer overall survival. Our analysis concludes that the dissection of ${\geq}15$ nodes is adequate for staging. However, the dissection of 29 nodes might be needed to provide a significantly improved survival.

• Journal of Gastric Cancer
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• v.21 no.1
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• pp.30-37
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• 2021

Purpose: While the amylase concentration of the drainage fluid (dAmy) has been reported to be a predictor of postoperative pancreas-related complications (PPRC), the optimal timing for its measurement has not been fully investigated. Materials and Methods: The clinicopathological data of 387 patients who underwent elective gastrectomy for gastric cancer were reviewed. Laboratory data, including dAmy on postoperative days 1 (dAmy1) and 3 (dAmy3), and serum C-reactive protein (sCRP) concentrations on postoperative days 1 (sCRP1) and 3 (sCRP3) were compared between patients with PPRC and without PPRC. Results: Nineteen of the 387 patients (4.9%) developed PPRC. The optimal cutoff values of dAmy1, dAmy3, sCRP1, and sCRP3 were 1514 IU/L, 761 IU/L, 8.32 mg/dL, and 15.15 mg/dL, respectively. The area under the curve of dAmy1 was greater than that of dAmy3 (0.915 vs. 0.826), and that of sCRP3 was greater than that of sCRP1 (0.820 vs. 0.659). In the multivariate analysis, dAmy1 (P<0.001) and sCRP3 (P=0.004) were significant predictors of PPRC, while dAmy3 (P=0.069) and sCRP1 (P=0.831) were not. Thirteen (41.9%) of 31 patients with both dAmy1 ≥1,545 IU/L and sCRP3 ≥15.15 mg/dL had PPRC ≥Clavien-Dindo II. In contrast, among 260 patients with both dAmy1 <1,545 IU/L and sCRP3 <15.15 mg/dL, none developed PPRC. Conclusions: dAmy1 was more useful than dAmy3 in predicting PPRC. The combination of dAmy1 and sCRP3 may be a useful criterion for the removal of drains on postoperative day 3.

• Journal of Gastric Cancer
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• v.21 no.4
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• pp.368-378
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• 2021

Purpose: When patients with early gastric cancer (EGC) undergo non-curative endoscopic submucosal dissection requiring gastrectomy (NC-ESD-RG), additional medical resources and expenses are required for surgery. To reduce this burden, predictive model for NC-ESD-RG is required. Materials and Methods: Data from 2,997 patients undergoing ESD for 3,127 forceps biopsy-proven differentiated-type EGCs (2,345 and 782 in training and validation sets, respectively) were reviewed. Using the training set, the logistic stepwise regression analysis determined the independent predictors of NC-ESD-RG (NC-ESD other than cases with lateral resection margin involvement or piecemeal resection as the only non-curative factor). Using these predictors, a risk-scoring system for predicting NC-ESD-RG was developed. Performance of the predictive model was examined internally with the validation set. Results: Rate of NC-ESD-RG was 17.3%. Independent pre-ESD predictors for NC-ESD-RG included moderately differentiated or papillary EGC, large tumor size, proximal tumor location, lesion at greater curvature, elevated or depressed morphology, and presence of ulcers. A risk-score was assigned to each predictor of NC-ESD-RG. The area under the receiver operating characteristic curve for predicting NC-ESD-RG was 0.672 in both training and validation sets. A risk-score of 5 points was the optimal cut-off value for predicting NC-ESD-RG, and the overall accuracy was 72.7%. As the total risk score increased, the predicted risk for NC-ESD-RG increased from 3.8% to 72.6%. Conclusions: We developed and validated a risk-scoring system for predicting NC-ESD-RG based on pre-ESD variables. Our risk-scoring system can facilitate informed consent and decision-making for preoperative treatment selection between ESD and surgery in patients with EGC.