Background: Community acquired lower respiratory tract infection (LRTI) is a leading cause for hospitalization in children and important cause for antibiotic prescription. We aimed to describe the aetiology of LRTI in children and analyse factors associated with bacterial or viral infection. Methods: Patients aged < 19 years with a diagnosis of LRTI were identified from the Observational Medical Outcomes Partnership Common Data Model Database of Seoul National University Bundang Hospital from January 2005–July 2019, and their clinical characteristics were obtained from the electronic medical records and retrospectively reviewed. Results: Among 5,924 cases of LRTI, 74.2% were pneumonia and 25.8% were bronchiolitis/ bronchitis. Patients’ median age was 1.8 (interquartile range, 3.1) years and 79.9% were < 5 years old. Pathogens were identified in 37.8%; 69.1% were viral and 30.9% were bacterial/ Mycoplasma pneumoniae. Respiratory syncytial virus was most common (70.9%) among viruses and M. pneumoniae (94.6%) was most common among bacteria. Viral LRTI was associated with winter, age < 2 years, rhinorrhoea, dyspnoea, lymphocytosis, thrombocytosis, wheezing, stridor, chest retraction, and infiltration on imaging. Bacteria/ M. pneumoniae LRTI was associated with summer, age ≥ 2 years, fever, decreased breathing sounds, leucocytosis, neutrophilia, C-reactive protein elevation, and positive imaging findings (consolidation, opacity, haziness, or pleural effusion). Conclusion In children with LRTI, various factors associated with viral or bacterial/ M. pneumoniae infections were identified, which may serve as guidance for antibiotic prescription.

Background: Community acquired lower respiratory tract infection (LRTI) is a leading cause for hospitalization in children and important cause for antibiotic prescription. We aimed to describe the aetiology of LRTI in children and analyse factors associated with bacterial or viral infection. Methods: Patients aged < 19 years with a diagnosis of LRTI were identified from the Observational Medical Outcomes Partnership Common Data Model Database of Seoul National University Bundang Hospital from January 2005–July 2019, and their clinical characteristics were obtained from the electronic medical records and retrospectively reviewed. Results: Among 5,924 cases of LRTI, 74.2% were pneumonia and 25.8% were bronchiolitis/ bronchitis. Patients’ median age was 1.8 (interquartile range, 3.1) years and 79.9% were < 5 years old. Pathogens were identified in 37.8%; 69.1% were viral and 30.9% were bacterial/ Mycoplasma pneumoniae. Respiratory syncytial virus was most common (70.9%) among viruses and M. pneumoniae (94.6%) was most common among bacteria. Viral LRTI was associated with winter, age < 2 years, rhinorrhoea, dyspnoea, lymphocytosis, thrombocytosis, wheezing, stridor, chest retraction, and infiltration on imaging. Bacteria/ M. pneumoniae LRTI was associated with summer, age ≥ 2 years, fever, decreased breathing sounds, leucocytosis, neutrophilia, C-reactive protein elevation, and positive imaging findings (consolidation, opacity, haziness, or pleural effusion). Conclusion In children with LRTI, various factors associated with viral or bacterial/ M. pneumoniae infections were identified, which may serve as guidance for antibiotic prescription.

Background: Community acquired lower respiratory tract infection (LRTI) is a leading cause for hospitalization in children and important cause for antibiotic prescription. We aimed to describe the aetiology of LRTI in children and analyse factors associated with bacterial or viral infection. Methods: Patients aged < 19 years with a diagnosis of LRTI were identified from the Observational Medical Outcomes Partnership Common Data Model Database of Seoul National University Bundang Hospital from January 2005–July 2019, and their clinical characteristics were obtained from the electronic medical records and retrospectively reviewed. Results: Among 5,924 cases of LRTI, 74.2% were pneumonia and 25.8% were bronchiolitis/ bronchitis. Patients’ median age was 1.8 (interquartile range, 3.1) years and 79.9% were < 5 years old. Pathogens were identified in 37.8%; 69.1% were viral and 30.9% were bacterial/ Mycoplasma pneumoniae. Respiratory syncytial virus was most common (70.9%) among viruses and M. pneumoniae (94.6%) was most common among bacteria. Viral LRTI was associated with winter, age < 2 years, rhinorrhoea, dyspnoea, lymphocytosis, thrombocytosis, wheezing, stridor, chest retraction, and infiltration on imaging. Bacteria/ M. pneumoniae LRTI was associated with summer, age ≥ 2 years, fever, decreased breathing sounds, leucocytosis, neutrophilia, C-reactive protein elevation, and positive imaging findings (consolidation, opacity, haziness, or pleural effusion). Conclusion In children with LRTI, various factors associated with viral or bacterial/ M. pneumoniae infections were identified, which may serve as guidance for antibiotic prescription.

Background: Community acquired lower respiratory tract infection (LRTI) is a leading cause for hospitalization in children and important cause for antibiotic prescription. We aimed to describe the aetiology of LRTI in children and analyse factors associated with bacterial or viral infection. Methods: Patients aged < 19 years with a diagnosis of LRTI were identified from the Observational Medical Outcomes Partnership Common Data Model Database of Seoul National University Bundang Hospital from January 2005–July 2019, and their clinical characteristics were obtained from the electronic medical records and retrospectively reviewed. Results: Among 5,924 cases of LRTI, 74.2% were pneumonia and 25.8% were bronchiolitis/ bronchitis. Patients’ median age was 1.8 (interquartile range, 3.1) years and 79.9% were < 5 years old. Pathogens were identified in 37.8%; 69.1% were viral and 30.9% were bacterial/ Mycoplasma pneumoniae. Respiratory syncytial virus was most common (70.9%) among viruses and M. pneumoniae (94.6%) was most common among bacteria. Viral LRTI was associated with winter, age < 2 years, rhinorrhoea, dyspnoea, lymphocytosis, thrombocytosis, wheezing, stridor, chest retraction, and infiltration on imaging. Bacteria/ M. pneumoniae LRTI was associated with summer, age ≥ 2 years, fever, decreased breathing sounds, leucocytosis, neutrophilia, C-reactive protein elevation, and positive imaging findings (consolidation, opacity, haziness, or pleural effusion). Conclusion In children with LRTI, various factors associated with viral or bacterial/ M. pneumoniae infections were identified, which may serve as guidance for antibiotic prescription.

Background: This study aimed to generate a Z score calculation model for coronary artery diameter of normal children and adolescents to be adopted as the standard calculation method with consensus in clinical practice. Methods: This study was a retrospective, multicenter study that collected data from multiple institutions across South Korea. Data were analyzed to determine the model that best fit the relationship between the diameter of coronary arteries and independent demographic parameters. Linear, power, logarithmic, exponential, and square root polynomial models were tested for best fit. Results: Data of 2,030 subjects were collected from 16 institutions. Separate calculation models for each sex were developed because the impact of demographic variables on the diameter of coronary arteries differs according to sex. The final model was the polynomial formula with an exponential relationship between the diameter of coronary arteries and body surface area using the DuBois formula. Conclusion A new coronary artery diameter Z score model was developed and is anticipated to be applicable in clinical practice. The new model will help establish a consensus-based Z score model.

Objectives: This study evaluated nutritional quality of convenience store meal boxes according to store company and meal price. Methods: In May 2020, 71 meal boxes from five major convenience store companies were collected. Respective weights of all dishes and food ingredients included in each meal box were measured with a digital scale. Information on nutritional contents was collected from nutrition fact panels on packages. Food group patterns, dietary diversity scores (DDS), and dietary variety scores (DVS) were analyzed. Nutritional contents, i.e., amounts of energy, protein, and sodium, and percentages of energy from carbohydrate, sugar, fat, and saturated fat were compared with respective standards based on the 2020 Dietary Reference Intakes for Koreans. Comparison was made among five companies (Company A, B, C, D, E) and three price groups ( ≤4,200 won, ≥4,300 and ≤4,500 won, ≥4,600 won). Multiple regression analyses were conducted to examine the difference of nutritional contents according to company and price, respectively while holding the other variable constant. Results: DDS, but not DVS, significantly differed among companies. The percentages of meal boxes meeting the nutritional standards of sodium significantly differed among companies; the percentage was highest in companies B (75.0%) and C (73.3%). “Company” was associated with amount of energy, protein, and sodium, and percentage of energy from saturated fat. “Price” was associated with the amount of energy and percentage of energy from carbohydrate. The average number of satisfied standards was highest in companies B (5.0) and C (4.0). About two-thirds of the meal boxes provided less amount of energy than the standard; the percentage of such meal boxes was highest in meal boxes with price of 4,200 won or lower. Conclusions There were significant differences in the nutritional quality of meal boxes according to “company”. Meanwhile, higher-priced meal boxes did not necessarily ensure better nutritional quality.

Purpose: The measurement of stool elastase (SE) level is useful for evaluating pancreatic exocrine function. This study aimed to determine the risk factors for severe exocrine pancreatic insufficiency (EPI) after pancreatoduodenectomy (PD), and analyze serial changes in nutritional markers and weight based on the SE level. Methods: Among patients who underwent PD for periampullary disease, patients whose preoperative and postoperative SE levels were measured were included in the study. The deteriorated (exocrine function) group comprised patients whose SE levels decreased from ≥100 µg/g preoperatively to <100 µg/g postoperatively. Patients whose weight 12 months postoperatively was greater than that 3 months postoperatively were classified into the weight-recovery group. Results: Of the 202 included patients, the deteriorated group had a higher incidence of preoperative SE level above 200 μg/ g, benign pathology, and the presence of a clinically relevant postoperative pancreatic fistula than the maintained group. Patients who did not undergo weight recovery had a higher rate of history of adjuvant radiotherapy compared to the norecovery group. Conclusion The evaluation of EPI by measuring SE alone is not sufficient because it does not reflect the nutritional status of patients, and a comprehensive approach that considers other parameters is required for EPI management.

Purpose: Postoperative pancreatic fistula (POPF) is the most troublesome complication after pancreaticojejunostomy (PJ).This study aimed to compare the short-term outcomes of 2 different methods of duct-to-mucosa PJ; out-layer continuous suture anastomosis (OCA) and the modified Blumgart method (mBM). Methods: This retrospective cohort study enrolled patients who underwent curative-intent, open PD between 2015 and 2020. In mBM, 2 transpancreatic U-sutures were performed between the pancreatic margin and jejunum, with reinforced sutures in the central region. Patient demographics, diagnosis, intraoperative factors, postoperative complications, and POPF defined by the International Study Group on Pancreatic Fistula were investigated. Clinically relevant POPF (CR-POPF) included grades B and C POPF. Results: A total of 184 patients underwent OCA, and 96 patients underwent mBM. The mBM group had more patients who underwent neoadjuvant therapy. The fistula risk scores were comparable between the 2 groups. Both groups showed no significant differences in CR-POPF and overall surgical complication rates. The total operation time was comparable, although the operation time for PJ was shorter in mBM. Conclusion No significant differences were observed in the postoperative outcomes between each group; the operation time for PJ in mBM was shorter. Therefore, mBM may be considered for utilization in duct-to-mucosa PJ.

Purpose: This study proposed the optimal definition of biochemical recurrence (BCR) after salvage radiotherapy (SRT) following radical prostatectomy for prostate cancer. Materials and Methods: Among 1,117 patients who had received SRT, data from 205 hormone-naïve patients who experienced post-SRT prostate-specific antigen (PSA) elevation were included in a multi-institutional database. The primary endpoint was to determine the PSA parameters predictive of distant metastasis (DM). Absolute serum PSA levels and the prostate-specific antigen doubling time (PSA-DT) were adopted as PSA parameters. Results: When BCR was defined based on serum PSA levels ranging from 0.4 ng/mL to nadir+2.0 ng/mL, the 5-year probability of DM was 27.6%-33.7%. The difference in the 5-year probability of DM became significant when BCR was defined as a serum PSA level of 0.8 ng/ml or higher (1.0-2.0 ng/mL). Application of a serum PSA level of ≥ 0.8 ng/mL yielded a c-index value of 0.589. When BCR was defined based on the PSA-DT, the 5-year probability was 22.7%-39.4%. The difference was significant when BCR was defined as a PSA-DT ≤ 3 months and ≤ 6 months. Application of a PSA-DT ≤ 6 months yielded the highest c-index (0.660). These two parameters complemented each other; for patients meeting both PSA parameters, the probability of DM was 39.5%-44.5%; for those not meeting either parameter, the probability was 0.0%-3.1%. Conclusion A serum PSA level > 0.8 ng/mL was a reasonable threshold for the definition of BCR after SRT. In addition, a PSA-DT ≤ 6 months was significantly predictive of subsequent DM, and combined application of both parameters enhanced predictability.