Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Objectives: Limited information is available concerning the epidemiology of stroke and acute myocardial infarction (AMI) in the Republic of Korea. This study aimed to develop a national surveillance system to monitor the incidence of stroke and AMI using national claims data. Methods: We developed and validated identification algorithms for stroke and AMI using claims data. This validation involved a 2-stage stratified sampling method with a review of medical records for sampled cases. The weighted positive predictive value (PPV) and negative predictive value (NPV) were calculated based on the sampling structure and the correspondingsampling rates. Incident cases and the incidence rates of stroke and AMI in the Republic ofKorea were estimated by applying the algorithms and weighted PPV and NPV to the 2018National Health Insurance Service claims data. Results: In total, 2,200 cases (1,086 stroke cases and 1,114 AMI cases) were sampled from the 2018 claims database. The sensitivity and specificity of the algorithms were 94.3% and 88.6% for stroke and 97.9% and 90.1% for AMI, respectively. The estimated number of cases, including recurrent events, was 150,837 for stroke and 40,529 for AMI in 2018. The age- and sex-standardized incidence rate for stroke and AMI was 180.2 and 46.1 cases per 100,000 person-years, respectively, in 2018. Conclusion This study demonstrates the feasibility of developing a national surveillance system based on claims data and identification algorithms for stroke and AMI to monitor their incidence rates.

Objective: Easy-to-understand information on emergency patient transportation and emergency medical resources is required to operate emergency medical resources appropriately. This study evaluated emergency patient transport routes using a geographic information system (GIS) and converted them into visual information to understand the current status of emergency medical resource use in the region. Methods: The basic data used in this study were collected from the 119 safety centers in Gangwon-do, South Korea, under the fire-fighting headquarters in Gangwon-do from January 2017 to December 2020. The data were analyzed using the geographic information system and converted to visual information. Results: The number of patients with cardiovascular disease, cerebrovascular disease, and traffic accidents was 12,944. Of these, 9,393 patients (72.6%) were transported from Chuncheon city, and 3,551 patients (27.4%) were transported out of Chuncheon city. The number of patients with cardiovascular diseases during the study period was 1,219 (9.4%); 782 patients (64.2%) were transported to the K-EMC (emergency medical center), and 437 patients (35.8%) were transported to the H-EMC. For cerebrovascular disease, 913 patients (7.1%) were transported to the EMC of Chuncheon city, with 585 (64.1%) K-EMC and 328 (35.9%) H-EMC patients. The number of traffic accident patients was 1,266 (9.8%). Five hundred and forty (42.7%) and 726 (57.3%) patients were transported to the K-EMC and H-EMC, respectively. Conclusion The adequacy of facilities, equipment, and human resources required to treat cardiac and cerebrovascular diseases in K-EMC and severe trauma in H-EMC needs to be reviewed.

Background: The epidemiology of pathogenic bacteria varies according to the socioeconomic status and antimicrobial resistance status. However, longitudinal epidemiological studies to evaluate the changes in species distribution and antimicrobial susceptibility of pathogenic bacteria nationwide are lacking. We retrospectively investigated the nationwide trends in species distribution and antimicrobial susceptibility of pathogenic bacteria over the last 20 years in Korea. Methods: From 1997 to 2016, annual cumulative antimicrobial susceptibility and species distribution data were collected from 12 university hospitals in five provinces and four metropolitan cities in South Korea. Results: The prevalence of Staphylococcus aureus was the highest (13.1%) until 2012 but decreased to 10.3% in 2016, consistent with the decrease in oxacillin resistance from 76.1% in 2008 to 62.5% in 2016. While the cefotaxime resistance of Escherichia coli increased from 9.0% in 1997 to 34.2% in 2016, E. coli became the most common species since 2013, accounting for 14.5% of all isolates in 2016. Pseudomonas aeruginosa and Acinetobacter baumannii rose to third and fifth places in 2008 and 2010, respectively, while imipenem resistance increased from 13.9% to 30.8% and 0.7% to 73.5% during the study period, respectively.Streptococcus agalactiae became the most common pathogenic streptococcal species in 2016, as the prevalence of Streptococcus pneumoniae decreased since 2010. During the same period, pneumococcal penicillin susceptibility decreased to 79.0%, and levofloxacin susceptibility of S. agalactiae decreased to 77.1% in 2016. Conclusion The epidemiology of pathogenic bacteria has changed significantly over the past 20 years according to trends in antimicrobial resistance in Korea. Efforts to confine antimicrobial resistance would change the epidemiology of pathogenic bacteria and, consequently, the diagnosis and treatment of infectious diseases.

Objective: Predicting the incidence of emergency patients can be very important for the efficient use of emergency medical resources and the deployment of 119 centers in a pre-hospital setting. The study was conducted to analyze the occurrence of emergency patients using geographic information systems in a pre-hospital setting in Korea. Methods: The basic data used in this study were collected from the 119 centers in Chuncheon-si, Korea, under the firefighting headquarters in Gangwon-do from January 2012 to December 2016. Results: The total number of patients transferred by 119 paramedics was 72,362. Of these, 9,904 (14.7%) were emergency patients; 519 (0.7%) had cardiovascular diseases; 383 (0.5%) had cerebrovascular diseases; 3,043 (4.2%) were trauma patients; 58,413 (80.7%) were non-emergency patients. The occurrence of emergency diseases was slightly lower in the Hyoja-dong area, and it was slightly higher in the area of the outskirts of the city. The incidence of heart disease was low in the Hyoja-dong and Nam-myeon areas, but the incidence of heart disease was highly observed in other areas. The number of trauma patients was 1,265 (41.6%) in the outskirts of the city, a suburban area, showing a relatively higher incidence than other emerging diseases. Conclusion The deployment of ambulances in Chuncheon-si should be carried out considering demographic characteristics and patient occurrence.

Objective: This study aimed to investigate the perception of emergency medical service (EMS) providers and medical directors toward the field skill proficiency of EMS providers. We further examined differences in perception according to the certification and hospital career of individuals. Methods: This survey was conducted enrolling all active EMS providers in Busan, Ulsan, and Gyeongnam, as well as emergency physicians who participated in direct medical direction. Pre-developed questionnaires were sent as text messages to individual EMS providers and emergency physicians using an internet-based survey tool (Google Forms).Questionnaires were composed of 25 items in 7 categories: “airway management”, “ventilatory support”, “circulatory support”, “field assessment and management of trauma patients”, “field assessment and management of patients with chest pain”, “field assessment and management of patients with neurologic symptoms”, and “other items”. The response was based on a five-point Likert scale, where 0 score indicated no experience at all. Results: The questionnaire was distributed to 1,781 EMS providers and 52 medical directors; of these, 1,314 (73.7%) EMS providers and 34 (65.3%) medical directors completed the survey. EMS providers rated themselves as above average (3 points) for most of the questions. However, the majority responded that they had no experience or low proficiency in endotracheal intubation and prehospital delivery (median 2; interquartile range [IQR], 0-3). Conversely, medical directors assessed the EMS provider’s proficiency as above average in use of I-gel, recognition of hypoglycemia, field management of trauma patients, use of oropharyngeal and nasopharyngeal airway, use of laryngeal mask airway, and optimal oxygen supply (median, 4; IQR, 3-4), but responded with low scores for most other questions. Based on the EMS provider certification, nurses scored themselves more proficient than level-1 emergency medical technicians (EMTs) for intravenous access (P<0.001), whereas level-1 EMTs recognized themselves more proficient than nurses for endotracheal intubation (P<0.001), use of Magill forceps (P=0.004), and pediatric cardiopulmonary resuscitation (P<0.001). Conclusion This study recognized the discrepancies in the perception of EMS provider’s field skill proficiency, as perceived by EMS providers and medical directors, and between level-1 EMTs and nurses. We propose that regional EMS authorities need to make persistent efforts to narrow these perception gaps through effective educational programs for EMS providers and medical directors.

Strongyloidiasis is caused by Strongyloides stercoralis and is one of the most neglected tropical diseases in tropical and subtropical regions. Although several strongyloidiasis cases have been reported in Korea, genetic analysis of Korean isolates is still incomplete. In this study, a parasite was isolated from a 61-year-old man diagnosed with strongyloidiasis during the treatment of lymphoma on his retroperitoneal lymph node. Diffuse symmetric wall thickening from the ascending to descending colon and a nematode-infected intestine was observed following microscopic examination. Genomic DNA was isolated from a patient tissue block, and S. stercoralis was identified by PCR and sequencing (18S rDNA). In order to determine phylogenetic location of a Korean isolate (named KS1), we analyzed cox1 gene (500-bp) and compared it with that from 47 previous S. stercoralis isolates (28 human isolates and 19 canid isolates) from Asian countries. Our results showed that phylogenetic tree could clearly be divided into 5 different groups according to hosts and regions. KS1 was most closely related with the Chinese isolates in terms of genetic distance.