Background: Since the emergence of hypervirulent strains of Clostridioides difficile, the incidence of C. difficile infections (CDI) has increased significantly. Methods: To assess the incidence of CDI in Korea, we conducted a prospective multicentre observational study from October 2020 to October 2021. Additionally, we calculated the incidence of CDI from mass data obtained from the Health Insurance Review and Assessment Service (HIRA) from 2008 to 2020. Results: In the prospective study with active surveillance, 30,212 patients had diarrhoea and 907 patients were diagnosed with CDI over 1,288,571 patient-days and 193,264 admissions in 18 participating hospitals during 3 months of study period; the CDI per 10,000 patientdays was 7.04 and the CDI per 1,000 admission was 4.69. The incidence of CDI was higher in general hospitals than in tertiary hospitals: 6.38 per 10,000 patient-days (range: 3.25–12.05) and 4.18 per 1,000 admissions (range: 1.92–8.59) in 11 tertiary hospitals, vs. 9.45 per 10,000 patient-days (range: 5.68–13.90) and 6.73 per 1,000 admissions (range: 3.18–15.85) in seven general hospitals. With regard to HIRA data, the incidence of CDI in all hospitals has been increasing over the 13-year-period: from 0.3 to 1.8 per 10,000 patient-days, 0.3 to 1.6 per 1,000 admissions, and 6.9 to 56.9 per 100,000 population, respectively. Conclusion The incidence of CDI in Korea has been gradually increasing, and its recent value is as high as that in the United State and Europe. CDI is underestimated, particularly in general hospitals in Korea.

Background: Consistent uptake of colorectal cancer (CRC) screening is important to reduce the incidence and mortality from advanced-stage CRC and increase the survival rate of the patients. We conducted a longitudinal study to determine the factors affecting CRC screening compliance in Korean adults using individual-level linked data from the Korean National Health and Nutrition Examination Survey, Korean National Health Insurance Service, and Korean Health Insurance Review and Assessment Service. Methods: We selected 3,464 adults aged 50–79 years as the study population and followed them for 12 years (January 2007–December 2018). The outcome variable was the level of adherence to CRC screening, categorized as nonadherent, intermittently adherent, and consistently adherent. An ordinal logistic regression model was designed to determine the socioeconomic factors, family history of CRC, and medical conditions that could facilitate the consistent uptake of CRC screening. Results: The results showed a significant and positive association between consistent uptake of CRC screening and the 100–150% income category (odds ratio [OR], 1.710; 95% confidence interval [CI], 1.401–2.088); clerical, sales and service job category (OR, 1.962; 95% CI, 1.582–2.433); residency at medium-sized cities (OR, 1.295; 95% CI, 1.094–1.532); high-school graduation (OR, 1.440; 95% CI, 1.210–1.713); married status (OR, 2.281; 95% CI, 1.946–2.674); use of employment-based national health insurance (OR, 1.820; 95% CI, 1.261–2.626); use of private insurance (OR, 2.259; 95% CI, 1.970–2.589); no disability (OR, 1.428; 95% CI, 1.175–1.737); family history of CRC (OR, 2.027; 95% CI, 1.514–2.714); and history of colorectal neoplasm (OR, 1.216; 95% CI; 1.039–1.422). Conclusion The lack of regular participation in CRC screening programs in the Republic of Korea was found to be an issue that requires attention. Policies on CRC screening must place increased emphasis on strengthening educational and public relations initiatives.

Background: Respiratory syncytial virus (RSV), a highly transmissible virus, is the leading cause of lower respiratory tract infections. We examined molecular changes in the RSV genome before and after the coronavirus disease 2019 (COVID-19) pandemic in Korea, and investigated whether drug-resistant mutations were present. Methods: In this prospective, single-center study, RSV-positive respiratory samples were collected between September 2019 and December 2022. Long-read whole-genome sequencing (WGS) was performed, and the presence of known drug-resistant substitutions for palivizumab, nirsevimab, and suptavumab was investigated. Results: Overall, 288 respiratory samples were collected from 276 children. WGS data were available for 133 samples (71 and 62 samples from the pre- and post-pandemic periods, respectively). All RSV-A strains (n = 56) belonged to the GA2.3.5 (ON1) genotype, whereas all RSV-B strains (n = 77) belonged to the GB5.0.5a (BA) genotype. No significant differences in genotypes were observed between the pre- and post-pandemic periods. In addition, no notable mutations related to nirsevimab or palivizumab resistance were detected in the F gene. However, the L172Q and S173L substitutions, which are known to confer resistance to suptavumab, were present in all RSV-B samples. Conclusion Despite the unprecedented interruption of RSV seasonality, there were no significant molecular changes in circulating RSV strains in Korea related to nirsevimab or palivizumab resistance before and after the COVID-19 pandemic. However, RSV-specific drug-resistance substitutions for suptavumab were identified.

Purpose: Asthma phenotypes are often defined by relative cell counts of airway granulocytes. Induced sputum test results enable clinicians to determine the inflammatory phenotype of asthma based on the eosinophil and neutrophil counts. This study aimed to investigate clinical characteristics of patients with asthma according to the inflammatory phenotype of their condition. Methods: Data from 107 patients with asthma reported at a single tertiary allergy center in Korea during October 2016 to January 2019 were obtained. Patients were categorized into 4 asthma phenotypes based on the cell counts on the induced sputum test: eosinophilic, neutrophilic, mixed, and paucigranulocytic types. Blood eosinophil count, total IgE level, eosinophil cationic protein, spirometric measurements, fractional exhaled nitric oxide, atopy based on the skin prick test, PC20 (provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second) in methacholine provocation test, type of asthma controller used, frequency of exacerbation, and use of systemic corticosteroids were examined. Results: The frequency of phenotype is as follows: eosinophilic (21.4%), neutrophilic (34.8%), mixed (13.4%), and paucigranulocytic types (30.4%). During the observation period, the proportion of patients who experienced an exacerbation and received systemic glucocorticosteroids were significantly lower in patients with the paucigranulocytic type of asthma than in those with the mixed type of asthma (6.3% vs. 40.0%; P = 0.007 and 5.9% vs. 40.0%; P = 0.004, respectively). Conclusion Paucigranulocytic asthma may be associated with lower incidence rates of asthma exacerbation and systemic corticosteroid use than the other phenotypes, classified according to induced sputum test results.

Background/Aims: The histologic status of the immune-tolerant (IT) phase of chronic hepatitis B relative to long-term outcomes is unclear. This study aimed to discover how the serological criteria currently in use correspond to histologic criteria in determining the IT phase and indication for liver biopsy. Methods: Patients in the serological IT phase determined by positive hepatitis B e antigen, hepatitis B virus (HBV) DNA ≥106 IU/mL, and normal or minimally elevated alanine aminotransferase (ALT) ≤60 IU/L, who underwent liver biopsy at three different hospitals were included. The distribution of the histologic IT phase, defined as fibrosis of stage 1 or less and inflammation of grade 1 or less, was compared with that of the serological IT phase. The risk factors for the incidence of liver-related events, such as hepatocellular carcinoma, liver cirrhosis, liver transplantation, and death, were also analyzed. Results: Eighty-two (31.7%) out of 259 clinically suspected IT phase patients belonged to the histologic IT phase. Age over 35, high AST, and low albumin were useful for ruling out the histologic IT phase. Risk factors predicting liver-related events were age and significant fibrosis stage. There was no significant difference in the proportion of histologic IT phase and clinical prognosis between normal ALT and mildly elevated ALT groups. However, even in patients with normal ALT, age was an important factor in predicting the presence of the histologic IT phase. Conclusions A significant number of patients who belonged to the serological IT phase were not in the histologic IT phase. Patients over 35 years and those with high AST, low albumin, and low HBV DNA levels were more likely to experience poor long-term clinical outcomes. Therefore, additional histologic assessment should be considered.

Objectives: As the Fourth Industrial Revolution advances, there is a growing interest in digital technology. In particular, the use of digital therapeutics (DTx) in healthcare is anticipated to reduce medical expenses. However, analytical research on DTx is still insufficient to fuel momentum for future DTx development. The purpose of this article is to analyze representative cases of different types of DTx from around the world and to propose a classification system. Methods: In this exploratory study examining DTx interaction types and representative cases, we conducted a literature review and selected seven interaction types that were utilized in a large number of cases. Then, we evaluated the specific characteristics of each DTx mechanism by reviewing the relevant literature, analyzing their indications and treatment components. A representative case for each mechanism was provided. Results: Cognitive behavioral therapy, distraction therapy, graded exposure therapy, reminiscence therapy, art therapy, therapeutic exercise, and gamification are the seven categories of DTx interaction types. Illustrative examples of each variety are provided. Conclusions Efforts from both the government and private sector are crucial for success, as standardization can decrease both the expense and the time required for government-led DTx development. The private sector should partner with medical facilities to stimulate potential demand, carry out clinical research, and produce scholarly evidence.

Background: Antimicrobial prescriptions for serious chronic or acute illness nearing its end stages raise concerns about the potential for futile use, adverse events, increased multidrugresistant organisms, and significant patient and social cost burdens. This study investigated the nationwide situation of how antibiotics are prescribed to patients during the last 14 days of life to guide future actions. Methods: This nationwide multicenter retrospective cohort study was conducted at 13 hospitals in South Korea from November 1 to December 31, 2018. All decedents were included in the study. Antibiotic use during the last two weeks of their lives was investigated. Results: A total of 1,201 (88.9%) patients received a median of two antimicrobial agents during the last two weeks of their lives. Carbapenems were prescribed to approximately half of the patients (44.4%) in the highest amount (301.2 days of therapy per 1,000 patient-days).Among the patients receiving antimicrobial agents, 63.6% were inappropriate and only 327 patients (27.2%) were referred by infectious disease specialists. The use of carbapenem (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.13–2.03; P = 0.006), underlying cancer (OR, 1.56; 95% CI, 1.20–2.01, P = 0.047), underlying cerebrovascular disease (OR, 1.88; 95% CI, 1.23–2.89, P = 0.004), and no microbiological testing (OR, 1.79; 95% CI, 1.15–2.73; P = 0.010) were independent predictors for inappropriate antibiotic prescribing. Conclusion A considerable number of antimicrobial agents are administered to patients with chronic or acute illnesses nearing their end-of-life, a high proportion of which are prescribed inappropriately. Consultation with an infectious disease specialist, in addition to an antimicrobial stewardship program, may be necessary to induce the optimal use of antibiotics.

Purpose: The balloon-stent technique (BST) has certain strengths as an assisted technique for the treatment of complex aneurysms. After Atlas release, the BST can be executed without an exchange maneuver of the balloon to the stent-delivery catheter. The purpose of this article is to share our experience with the BST using the Scepter-Atlas combination. Materials and Methods: Device inspection led us to a simple method to avoid failure in loading Atlas to the Scepter. From March 2018 to December 2019, 57 unruptured distal internal carotid artery (dICA) aneurysms were treated with coil embolization; among which, 25 aneurysms in 23 patients were treated with BST. Clinical and angiographic data were retrospectively collected and reviewed. Results: The technical success rate of the Scepter-Atlas combination increased from 50% to 100% after careful inspection. BST angiographic results were comparable to the stent-assisted coil (SAC) group treated during the immediately post-embolization same period (modified Raymond-Roy classification [MRRC] 1 & 2 84% in BST, 96.3% in SAC) and during short-term follow-up (MRRC 1 & 2 95.8% in BST, 88.4% in SAC). A small number of patients showed periprocedural complications, but none had clinical consequences. Conclusion BST using the Scepter-Atlas combination can provide an effective and safe method for the treatment of dICA aneurysms. Scepters can be used as delivery catheters for Atlas.

Purpose: The balloon-stent technique (BST) has certain strengths as an assisted technique for the treatment of complex aneurysms. After Atlas release, the BST can be executed without an exchange maneuver of the balloon to the stent-delivery catheter. The purpose of this article is to share our experience with the BST using the Scepter-Atlas combination. Materials and Methods: Device inspection led us to a simple method to avoid failure in loading Atlas to the Scepter. From March 2018 to December 2019, 57 unruptured distal internal carotid artery (dICA) aneurysms were treated with coil embolization; among which, 25 aneurysms in 23 patients were treated with BST. Clinical and angiographic data were retrospectively collected and reviewed. Results: The technical success rate of the Scepter-Atlas combination increased from 50% to 100% after careful inspection. BST angiographic results were comparable to the stent-assisted coil (SAC) group treated during the immediately post-embolization same period (modified Raymond-Roy classification [MRRC] 1 & 2 84% in BST, 96.3% in SAC) and during short-term follow-up (MRRC 1 & 2 95.8% in BST, 88.4% in SAC). A small number of patients showed periprocedural complications, but none had clinical consequences. Conclusion BST using the Scepter-Atlas combination can provide an effective and safe method for the treatment of dICA aneurysms. Scepters can be used as delivery catheters for Atlas.

Background: Reproductive factors such as childbirth, gravidity, age of menarche, breastfeeding, and use of oral contraceptives could affect the risk of cardiovascular disease in women. This study aimed to investigate the relationship between reproductive factors and cardiovascular disease in postmenopausal women in Korea. Methods: This study included 2,310 women aged ≥45 years who experienced natural menopause and participated in the 7th Korea National Health and Nutrition Examination Survey (2016–2017). Cardiovascular disease was defined as myocardial infarction, angina, and stroke. Coronary heart disease was defined as myocardial infarction and angina. Logistic regression was performed to calculate the odds ratio of cardiovascular disease with respect to each reproductive factor. Results: Women who breastfed for longer duration (≥24 months) group had a 3-fold higher risk of cardiovascular disease and 4–5-fold higher risk of coronary heart disease than those in the non-breastfeeding group. One-time pregnancy was associated with a higher risk of coronary heart disease than gravidity of 6. Early menarche (≤11 years of age) was associated with a high risk of stroke. Women who had a history of using oral contraceptives were at low risk of stroke. Conclusion Breastfeeding, low gravidity, and early menarche were associated with an increased risk of cardiovascular disease, whereas use of oral contraceptives was associated with reduced risk of stroke. However, some of these results were different from previous reports. Therefore, further studies are needed to identify the relationship between reproductive factors and cardiovascular disease in women.