The purpose of this study were to : (a) analyzed price elasticity of university students in foodservice operations and (b)provide insight for price decision-making. Questionnaires were composed of price elasticity, the utilization and opinions of students on university foodservice operations, and demographic information regarding respondents. The questionnaires were distributed to 600 university students of 6 universities located in Seoul. Statistical data analysis was completed using the SAS package for descriptive analysis, t-test, ANOVA, and Pearson's correlation. The results of this study can be summarized as follows: The average price for lunch was 1,663 won for campus food, and 2,965 won for off-campus restaurants. The frequency of utilizing the university cafeteria was fairly high. Students felt that the proper price for lunch was 1,446 won, presenting a lower price than the actual average price for lunch. The price elasticity was investigated in relation to the change in utilization rate when these was a price increase. The price elasticity was 2.03, with significant differences between sex, age, and major. The groups utilizing the university cafeteria frequently, taking longer time to go to off-campus or that were satisfied with the university cafeteria, had a lower price elasticity than those that did not. The results of this study suggest that predicting the price elasticity of the target market would assist the pricing policy, and the fact that the same students have different price elasticity by place and atmosphere can be used in marketing strategies.
Atmosphere ; Surveys and Questionnaires ; Data Interpretation, Statistical ; Elasticity* ; Humans ; Lunch ; Marketing ; Restaurants ; Seoul

The propensity score is defined as the probability of each individual study subject being assigned to a group of interest for comparison purposes. Propensity score adjustment is a method of ensuring an even distribution of confounders between groups, thereby increasing between group comparability. Propensity score analysis is therefore an increasingly applied statistical method in observational studies. The purpose of this article was to provide a step-by-step nonmathematical conceptual guide to propensity score analysis with particular emphasis on propensity score matching. A software program code used for propensity score matching was also presented.
Female ; Humans ; Male ; Middle Aged ; *Propensity Score ; Radiology/*methods ; Research Design ; Research Personnel ; Software

Background and Objectives: Human mesenchymal stem cells (MSCs) are emerging as a treatment for atopic dermatitis (AD), a chronic inflammatory skin disorder that affects a large number of people across the world. Treatment of AD using human umbilical cord blood-derived MSCs (hUCB-MSCs) has recently been studied. However, the mechanism underlying their effect needs to be studied continuously. Thus, the objective of this study was to investigate the immunomodulatory effect of epidermal growth factor (EGF) secreted by hUCB-MSCs on AD. Methods: and Results: To explore the mechanism involved in the therapeutic effect of MSCs for AD, a secretome array was performed using culture medium of hUCB-MSCs. Among the list of genes common for epithelium development and skin diseases, we focused on the function of EGF. To elucidate the effect of EGF secreted by hUCB-MSCs, EGF was downregulated in hUCB-MSCs using EGF-targeting small interfering RNA. These cells were then co-cultured with keratinocytes, Th2 cells, and mast cells. Depletion of EGF disrupted immunomodulatory effects of hUCB-MSCs on these AD-related inflammatory cells. In a Dermatophagoides farinae-induced AD mouse model, subcutaneous injection of hUCB-MSCs ameliorated gross scoring, histopathologic damage, and mast cell infiltration. It also significantly reduced levels of inflammatory cytokines including interleukin (IL)-4, tumor necrosis factor (TNF)-α, thymus and activation-regulated chemokine (TARC), and IL-22, as well as IgE levels. These therapeutic effects were significantly attenuated at all evaluation points in mice injected with EGF-depleted hUCB-MSCs. Conclusions EGF secreted by hUCB-MSCs can improve AD by regulating inflammatory responses of keratinocytes, Th2 cells, and mast cells.

This paper aims to introduce Korea’s total current health expenditure (CHE) and National Health Accounts of the year 2021 and their 2022 preliminary figures constructed on the basis of the System of Health Accounts 2011. As CHE includes expenditures for prevention, tracking, and treatment of coronavirus disease 2019 (COVID-19) and compensation for losses to medical institutions from 2020, the details are also introduced. Korea’s total CHE in 2021 is 193.3 trillion won, which is 9.3% of gross domestic product (GDP). The preliminary figure in 2022, 209.0 trillion won, exceeded the 200 trillion won line for the first time, and its “ratio to GDP” of 9.7% is expected to exceed the average of Organisation for Economic Co-Operation and Development member countries for the first time. Korea’s health expenditures, which were well controlled until the end of the 20th century, have increased at an alarming rate since the beginning of the 21st century, threatening the sustainability of national health insurance. The increase in health expenditure after 2020 is partly due to a temporary increase in response to COVID-19. However, when considering the structure of Korea’s health insurance price hike, where the ratchet effect of increased medical expenses works particularly strongly, it is unlikely that the accelerating growth trend that has lasted for more than 20 years will stop easily. More aggressive policies to control medical expenses are required in the national health insurance which not only constitutes the main financing sources of the Korean health system but also has the most powerful policy means in effect for changes in the health care provision.

BACKGROUND: The purpose of this study was to document outcomes following withdrawal of a single inhaler (step-down) in chronic obstructive pulmonary disease (COPD) patients on triple therapy (long-acting muscarinic antagonist and a combination of long-acting beta2-agonists and inhaled corticosteroid), which a common treatment strategy in clinical practice. METHODS: Through a retrospective observational study, COPD patients receiving triple therapy over 2 years (triple group; n=109) were compared with those who had undergone triple therapy for at least 1 year and subsequently, over 9 months, initiated inhaler withdrawal (step-down group, n=39). The index time was defined as the time of withdrawal in the stepdown group and as 1 year after the start of triple therapy in the triple group. RESULTS: Lung function at the index time was superior and the previous exacerbation frequency was lower in the stepdown group than in the triple group. Step-down resulted in aggravating disease symptoms, a reduced overall quality of life, decreasing exercise performance, and accelerated forced expiratory volume in 1 second (FEV1) decline (54.7+/-15.7 mL/yr vs. 10.7+/-7.1 mL/yr, p=0.007), but there was no observed increase in the frequency of exacerbations. CONCLUSION: Withdrawal of a single inhaler during triple therapy in COPD patients should be conducted with caution as it may impair the exercise capacity and quality of life while accelerating FEV1 decline.
Forced Expiratory Volume ; Humans ; Lung ; Lung Diseases ; Nebulizers and Vaporizers* ; Observational Study ; Pulmonary Disease, Chronic Obstructive* ; Quality of Life ; Retrospective Studies

BACKGROUND/AIMS: Endoscopic resection (ER) of superficial esophageal neoplasm (SEN) is a technically difficult procedure. We investigated the clinical outcomes of ER for SEN to determine its feasibility and effectiveness. METHODS: Subjects who underwent ER for SEN at Asan Medical Center between December 1996 and December 2010 were eligible. The clinical features of patients and tumors, histopathological characteristics, adverse events, ER results and survival were investigated. RESULTS: A total of 129 patients underwent ER for 147 SENs. En bloc resection (EnR) was performed in 118 lesions (80.3%). Complete resection (CR) was accomplished in 128 lesions (86.5%), and curative resection (CuR) was performed in 118 lesions (79.7%). The EnR, CR, and CuR rates were significantly greater in the endoscopic submucosal dissection group when compared to those in the endoscopic resection group. Adverse events occurred in 22 patients (17.1%), including bleeding (n=2, 1.6%), perforation (n=12, 9.3%), and stricture (n=8, 6.2%). Local tumor recurrence occurred in 2.0% of patients during a median follow-up of 34.8 months. The 5-year overall and disease-specific survival rates were 94.0% and 97.5%, respectively. CONCLUSIONS: ER is a feasible and effective method for the treatment of SEN as indicated by favorable clinical outcomes.
Aged ; Aged, 80 and over ; Disease-Free Survival ; Dissection/*adverse effects/methods ; Esophageal Neoplasms/pathology/*surgery ; Esophageal Perforation/epidemiology/etiology ; Esophageal Stenosis/epidemiology/etiology ; Esophagoscopy/*adverse effects/methods ; Female ; Gastric Mucosa/surgery ; Humans ; Male ; Middle Aged ; Neoplasm Recurrence, Local/epidemiology ; Postoperative Hemorrhage/epidemiology/etiology ; Retrospective Studies ; Treatment Outcome

PURPOSE: The purpose of this study was to compare treatment outcomes between combined gonadotropin-releasing hormone agonist and tamoxifen (GnRHa+T) and sequential adriamycin and cyclophosphamide chemotherapy and tamoxifen (AC->T) in premenopausal patients with hormone-responsive, lymph-node–negative breast cancer. MATERIALS AND METHODS: In total, 994 premenopausal women with T1-T2, lymph-node–negative, hormone-receptor-positive, HER2-negative breast cancer between January 2003 and December 2008 were included in this retrospective cohort study. GnRHa+T and AC->T were administered to 608 patients (61.2%) and 386 patients (38.8%), respectively. Propensity score matching and inverse probability weighting were applied to the original cohort, and 260 patients for each treatment arm were included in the final analysis. Recurrence-free, cancer-specific, and overall survival was compared between the two treatment groups. RESULTS: A total of 994 patients were followed up for a median of 7.4 years (range, 0.5 to 11.4 years). The 5-year follow-up rate was 98.7%, and 13 patients were lost to follow-up. In propensity-matched cohorts (n=520), there was no difference in recurrence-free, cancer-specific, and overall survival rates between the two treatment groups (p=0.306, p=0.212, and p=0.102, respectively), and this was maintained after applying inverse probability weighting. CONCLUSION: GnRHa+T is a reasonable alternative to AC->T in patients with premenopausal, hormone-responsive, HER2-negative, lymph-node–negative, T1-T2 breast cancer.
Arm ; Breast Neoplasms* ; Breast* ; Cohort Studies ; Cyclophosphamide* ; Doxorubicin* ; Drug Therapy* ; Female ; Follow-Up Studies ; Gonadotropin-Releasing Hormone* ; Humans ; Lost to Follow-Up ; Premenopause ; Propensity Score ; Retrospective Studies ; Survival Rate ; Tamoxifen*

To date, clinico-physiologic indices have not been compared with quantitative CT imaging indices in determining the risk of chronic obstructive pulmonary disease (COPD) exacerbation. We therefore compared clinico-physiologic and CT imaging indices as risk factors for COPD exacerbation in patients with COPD. We retrospectively analyzed 260 COPD patients from pulmonary clinics at 11 hospitals in Korea from June 2005 to November 2009 and followed-up for at least one year. At the time of enrollment, none of these patients had COPD exacerbations for at least 2 months. All underwent clinico-physiologic and radiological evaluation for risk factors of COPD exacerbation. After 1 yr, 106 of the 260 patients had at least one exacerbation of COPD. Multiple logistic regression analysis showed that old age, high Charlson Index, and low FEV1 were significant in a clinico-physiologic model, with C-statistics of 0.69, and that increased age and emphysema index were significant in a radiologic model, with C-statistics of 0.64. The difference between the two models was statistically significant (P = 0.04 by bootstrap analysis). Combinations of clinico-physiologic risk factors may be better than those of imaging risk factors in predicting COPD exacerbation.
Aged ; Aged, 80 and over ; Disease Progression ; Female ; Humans ; Male ; Middle Aged ; Pulmonary Disease, Chronic Obstructive/*diagnosis/pathology/*physiopathology ; Retrospective Studies ; Risk Factors ; Severity of Illness Index ; *Tomography, X-Ray Computed

PURPOSE: Cigarette smoking (CS) is one of the major risk factors of cerebral atherosclerotic disease, however, its level of contribution to extracranial and intracranial atherosclerotic stenosis (ECAS and ICAS) was not fully revealed yet. The purpose of our study was to assess the association of CS to cerebral atherosclerosis along with other risk factors. MATERIALS AND METHODS: All consecutive patients who were angiographically confirmed with severe symptomatic cerebral atherosclerotic disease between January 2002 and December 2012 were included in this study. Multivariate logistic regression analyses were performed to identify risk factors for ECAS and ICAS. Thereafter, CS group were compared to non-CS group in the entire study population and in a propensity-score matched population with two different age-subgroups. RESULTS: Of 1709 enrolled patients, 794 (46.5%) had extracranial (EC) lesions and the other 915 (53.5%) had intracranial (IC) lesions. CS group had more EC lesions (55.8% vs. 35.3%, P<0.001) whereas young age group (<50 years) had more IC lesion (84.5% vs. 47.6%, P<0.001). In multivariate analysis, seven variables including CS, male, old age, coronary heart disease, higher erythrocyte sedimentation rate, multiple lesions, and anterior lesion were independently associated with ECAS. In the propensity-score matched CS group had significant more EC lesion compared to non-CS group (65.7% vs. 47.9%) only in the old age subgroup. CONCLUSION: In contrast to a significant association between CS and severe symptomatic ECAS shown in old population, young patients did not show this association and showed relatively higher preference of ICAS.
Atherosclerosis ; Blood Sedimentation ; Cerebrovascular Circulation ; Constriction, Pathologic ; Coronary Disease ; Humans ; Intracranial Arteriosclerosis ; Logistic Models ; Male ; Multivariate Analysis ; Risk Factors ; Smoking ; Tobacco Products