Background: Hypersensitivity pneumonitis (HP) is a condition with an uncertain global incidence, and information on its diagnosis and management is limited. This study aimed to address these knowledge gaps. Methods: This study utilized customized claims data from the Health Insurance Review and Assessment Service (HIRA) in South Korea from January 2010, to December 2021. Patients with HP were identified based on the diagnosis code (International Classification of Diseases, 10th Revision, J67) between 2011 and 2020. Incident HP cases were defined as new HP claims, excluding those with claims in the previous year. The study examined various factors such as age, sex, comorbidities, diagnostic methods, and treatment patterns. Additionally, multivariate logistic regression analysis was performed to identify risk factors associated with treatment initiation. Results: A total of 8,678 HP incident cases were confirmed, with age- and sex-adjusted annual incidence rates ranging from 1.14/100,000 in 2020 to 2.16/100,000 in 2012. The mean age of patients with incident HP was 52 years, with a higher incidence observed among males. Additionally, the most common comorbidity was asthma. Bronchoscopy was performed on 16.9% of patients, and 25.4% of patients did not receive treatment within 1 year of diagnosis. Among those who received treatment, prednisone was the most used systemic steroid, and azathioprine was the most commonly used second-line immunosuppressant.Factors associated with treatment initiation included the female sex, having asthma or gastroesophageal reflux disease (GERD), and undergoing bronchoscopy. Conclusion This study provides valuable insights into the incidence, diagnosis, and treatment patterns of HP in South Korea using nationwide medical claims data.

Background: Hand hygiene is considered the simplest and most cost-effective method of infection prevention. Regular observation and feedback on hand hygiene compliance are key strategies for its enhancement. This study evaluated the effectiveness of hand hygiene surveillance, including direct observation and feedback, by comprehensively analyzing the reported hand hygiene compliance within the Korean National Healthcare-Associated Infections Surveillance System from 2019 to 2022. Methods: Participating medical institutions included general hospitals and hospitals with infection control departments that consented to participate. Hand hygiene surveillance was conducted using direct observation. Collected data, including healthcare workers, clinical areas, hand hygiene moments, and hand hygiene compliance, were recorded to calculate hand hygiene compliance rates. Additionally, the volume of alcohol-based hand sanitizers used per patient per day was investigated as an indirect indicator of hand hygiene compliance. The study was conducted from July 2019 to December 2022. Results: Hand hygiene compliance increased from 87.2% in Q3 2019 to 89.9% in 2022. Nurses and medical technologists showed the highest compliance rates, whereas doctors showed the lowest compliance rates. Intensive care units excelled in compliance, whereas emergency de partments lagged. Compliance was highest after patient contact and lowest when the patient’s surroundings were touched. Larger hospitals consumed more alcohol-based hand sanitizers than smaller hospitals did. Conclusion This study confirmed an improvement in hand hygiene compliance through sustained surveillance, indicating its contribution not only to preventing infection transfer within healthcare facilities but also to fostering a culture of hand hygiene in the country.

Background: Elderly patients with hip fractures frequently receive perioperative transfusions, which are associated with increased morbidity and mortality. This study aimed to evaluate the impact of a patient blood management (PBM) program on the appropriateness of red blood cell (RBC) transfusion and clinical outcomes in geriatric patients undergoing hip fracture surgery. Methods: In 2018, the revised PBM program was implemented at the Korea University Anam Hospital, Seoul, Republic of Korea. Elderly patients aged ≥ 65 years who underwent hip fracture surgery from 2017 to 2020 were evaluated. Clinical characteristics and outcomes were analyzed according to the timing of PBM implementation (pre-PBM, early-PBM, and late-PBM). Multiveriate regression analysis was used to evaluate the risk factors of the adverse outcomes, such as in-hospital mortality or 30-day readmission. Results: A total of 884 elderly patients were included in this study. The proportion of patients who received perioperative RBC transfusions decreased significantly (43.5%, 40.1%, and 33.2% for pre-PBM, early-PBM, and late-PBM, respectively; P = 0.013). However, the appropriateness of RBC transfusion significantly increased (54.0%, 60.1%, and 94.7%, respectively; P < 0.001). The duration of in-hospital stay and 30-day readmission rates significantly decreased. Multivariable regression analysis revealed that RBC transfusion (odds ratio, 1.815; 95% confidence interval, 1.137–2.899; P = 0.013) was significantly associated with adverse outcomes. Conclusion Implementing the PBM program increased the appropriateness of RBC transfusion without compromising transfusion quality and clinical outcomes. Therefore, adopting the PBM program may improve the clinical management of elderly patients following hip fracture surgery.

Background: This study aimed to investigate perceptions of Clostridioides difficile infection (CDI) diagnostic tests among physicians who prescribe CDI diagnostic tests as part of providing direct patient care. Methods: In August 2018, we provided a 12-question survey of gastroenterologists (the most common referral source for CDI testing) to 35 medical institutions in Korea, asking them about their perceptions of CDI diagnosis and testing. Results: A comparison of the perceptions of physicians and clinical pathologists (CPs) found that physicians had a lower perceived sensitivity of the toxin AB enzyme immunoassay test. For nucleic acid amplification tests, physicians exhibited a perception of higher assay sensitivity and specificity than CPs. The specificity of culture tests was generally perceived as high by physicians, whereas CPs regarding expressed mixed opinions. All but one physician and one CPs found the algorithmic test useful. Concerning the CDI isolation criteria, physicians commenced patient isolation by concurrently assessing both test results and clinical symptoms, rather than exclusively relying upon test results. Among CPs, 84.6% said they could rely on symptoms to determine when to release a patient from isolation, while 46.2% of physicians said they would rely on test results. Conclusion This study provides useful information on the status of laboratory diagnosis of CDI in Korea and what needs to be improved, which will help to standardize and improve laboratory diagnosis of CDI in Korea.

Background: Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing. Methods: We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples. Results: Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing. Conclusions The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk.

Purpose: To evaluate the feasibility of pediatric low-dose facial CT reconstructed with filtered back projection (FBP) using adequate kernels. Materials and Methods: We retrospectively reviewed the clinical and imaging data of children aged < 10 years who underwent facial CT at our emergency department. The patients were divided into two groups: low-dose CT (LDCT; Group A, n = 73) with a fixed 80-kVp tube potential and automatic tube current modulation (ATCM) and standard-dose CT (SDCT; Group B, n = 40) with a fixed 120-kVp tube potential and ATCM. All images were reconstructed with FBP using bone and soft tissue kernels in Group A and only bone kernel in Group B. The groups were compared in terms of image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Two radiologists subjectively scored the overall image quality of bony and soft tissue structures. The CT dose index volume and dose-length product were recorded. Results: Image noise was higher in Group A than in Group B in bone kernel images (p < 0.001). Group A using a soft tissue kernel showed the highest SNR and CNR for all soft tissue structures (all p < 0.001). In the qualitative analysis of bony structures, Group A scores were found to be similar to or higher than Group B scores on comparing bone kernel images. In the qualitative analysis of soft tissue structures, there was no significant difference between Group A using a soft tissue kernel and Group B using a bone kernel with a soft tissue window setting (p > 0.05). Group A showed a 76.9% reduction in radiation dose compared to Group B (3.2 ± 0.2 mGy vs. 81.9 ± 11.1 mGy; p < 0.001). Conclusion The addition of a soft tissue kernel image to conventional CT reconstructed with FBP enables the use of pediatric low-dose facial CT protocol while maintaining image quality.

Background: The interest in Clostridioides difficile infection (CDI) has increased, and the choice of assays became wider since the first national survey in Korea on CDI diagnosis in 2015. We conducted a survey of the domestic CDI assays with more varied questions to understand the current situation in Korea. Methods: In April 2018, about 50 questions on the current status of CDI assays and details on implementation and perceptions were written, and a survey questionnaire was administered to laboratory medicine specialists in 200 institutions. Results: One-hundred and fifty institutions responded to the questionnaire, of which 90 (60.0%) including one commercial laboratory, performed CDI assays. The toxin AB enzyme immunoassay (toxin AB EIA), nucleic acid amplification test (NAAT), and C. difficile culture, glutamate dehydrogenase assay, alone or in combination with other assays, were used in 75 (84.3%), 52 (58.4%), 35 (36.0%), and 23 (25.8%), respectively, and 65 (73.0%) institutions performed a combination of two or more assays. The sensitivity of toxin AB EIA was more negatively perceived, and that on specificity was more positively perceived. The perception of sensitivity and specificity of NAAT was mostly positive. Perception on the algorithm test projected it as useful but in need of countermeasures. Sixty-three (73.3%) institutions responded that they performed surveillance on CDI. Conclusion This study provides useful evidence on the current status of CDI laboratory diagnosis in Korea as well as on items that require improvement and is thought to aid in standardizing and improving the CDI laboratory diagnosis in Korea.

Purpose: To assess the prevalence of incidentally detected lumbar spondylolysis in children. Materials and Methods: We retrospectively reviewed the data of 809 patients under the age of 11 years (mean age, 7.0 ± 2.7 years; boys:girls = 479:330) who underwent abdominal and pelvic CT between March 2014 and December 2018. We recorded the presence, level, and laterality (unilateral or bilateral) of spondylolysis. Patients were divided into two groups based on the presence of spondylolysis: the spondylolysis (SP) and non-SP groups. Results: In total, 21 cases of spondylolysis were detected in 20 patients (20/809, 2.5%). The mean age of the SP group was higher than that of the non-SP group (7.8 ± 1.8 vs. 6.9 ± 2.7 years, p > 0.05). The prevalence of spondylolysis in boys was higher than that in girls (15/479 [3.1%] vs. 5/330 [1.5%], p > 0.05). The prevalence of spondylolysis in school-age children (6–10 year olds) was higher than that in preschool-age children (0–5 year olds) (17/538 [3.2%] vs. 3/271 [1.1%], p > 0.05). L5 was the most common level of spondylolysis (76.2%); one 8-year-old boy had twolevel spondylolysis. One case of isthmic spondylolisthesis was detected in a 10-year-old boy (1/809, 0.1%). There were 11 unilateral spondylolysis cases (11/21, 52.4%). Conclusion In our study, the prevalence of spondylolysis in children under the age of 11 was 2.5%. The prevalence was higher in boys than in girls and in school-age than in preschool-age children, despite the lack of any statistically significant differences.

Aging has become a global problem, and the interest in healthy aging is growing. Healthy aging involves a focus on the maintenance of the function and well-being of elderly adults, rather than a specific disease. Thus, the management of frailty, which is an accumulated decline in function, is important for healthy aging. The adaptation method was used to develop clinical practice guidelines on frailty management that are applicable in primary care settings. The guidelines were developed in three phases: preparation (organization of committees and establishment of the scope of development), literature screening and evaluation (selection of the clinical practice guidelines to be adapted and evaluation of the guidelines using the Korean Appraisal of Guidelines for Research and Evaluation II tool), and confirmation of recommendations (three rounds of Delphi consensus and internal and external reviews). A total of 16 recommendations (five recommendations for diagnosis and assessment, 11 recommendations for intervention of frailty) were made through the guideline development process. These clinical practice guidelines provide overall guidance on the identification, evaluation, intervention, and monitoring of frailty, making them applicable in primary care settings. As aging and “healthy aging” become more and more important, these guidelines are also expected to increase in clinical usefulness.

Newborn gastrointestinal tract emergency diseases include various disorders that occur anywhere along the digestive tract. Most of them are congenital malformations, not acquired diseases. Many of them cannot be confirmed on prenatal examination, and consequently, postnatal evaluation is required. Unlike adults, in newborn babies, detailed evaluations with computed tomography (CT) and magnetic resonance imaging (MRI) are often limited, so making the diagnosis based on early abdominal radiography is most important. Therefore, it is necessary to be familiar with the radiologic findings that may be seen on imaging studies. In addition, it is important to understand abdominal ultrasound and fluoroscopy findings, which can be used in addition to simple radiography and indications that can be used for further diagnosis and appropriate treatment. Therefore, this study describes and organizes the various imaging findings that may occur in neonatal gastrointestinal emergencies.