Objectives: Smoking remains the leading cause of preventable disease. However, smokers have shown poor compliance with smoking cessation clinics. Smartphone applications present a promising opportunity to improve this compliance. This study aimed to explore the relationship between nicotine dependence, smartphone usage patterns, and anticipated compliance with a smoking cessation application among smokers, with the goal of informing future development of such applications. Methods: A total of 53 current smokers were surveyed using a questionnaire. Nicotine dependence was assessed using the Fagerstrom Test for Nicotine Dependence (FTND). Variables included the number of hours spent using a phone, willingness to quit smoking, number of previous quit attempts, desired number of text messages about smoking cessation, expected duration of application usage, and FTND scores. Kendall’s partial correlation, adjusted for age, was employed for the analysis. Results: The amount of time smokers spent on their mobile devices was negatively correlated with the number of smoking cessation text messages they wanted to receive (τ coefficient = –0.210, p = 0.026) and the duration they intended to use the cessation application (τ coefficient = –0.260, p = 0.006). Conversely, the number of desired text messages was positively correlated with the intended duration of application usage (τ coefficient = 0.366, p = 0.00012). Conclusions Smokers who spent more time on their mobile devices tended to prefer using the cessation application for shorter periods, whereas those who desired more text messages about smoking cessation were more inclined to use the application for longer durations.

Objective: The objective of this nationwide, long-term follow-up study was to explore the connection between congestive heart failure (CHF) and ossification of the posterior longitudinal ligament (OPLL) in Korea. Methods: Patient information was collected from the Health Screening cohort of the National Health Insurance Service. Individuals diagnosed with OPLL were identified using specific International Classification of Diseases, 10th revision codes (M48.8, M48.81, M48.82, and M48.83). A total of 1,289 OPLL patients and 6,445 controls were included in the study, selected through 1:5 age and sex matching. The data spanned from January 1, 2004 to July 31, 2015. To compute the incidence rate of CHF in each group, the Kaplan-Meier method was employed. Additionally, Cox proportional-hazards regression analysis was utilized to estimate the hazard ratio of CHF. Results: CHF was present in 19 patients (1.47%) in the OPLL group and 71 patients (1.10%) in the control group. After accounting for age and sex, the hazard ratio for CHF in the OPLL group was 3.164 (95% confidence interval [CI], 1.867-5.360). When additionally considering income and underlying diseases, the hazard ratio for CHF within the OPLL group was 3.355 (95% CI, 1.977-5.694). All subgroups of OPLL patients exhibited an increased risk ratio for CHF across parameters such as sex, age, diabetes, hypertension, and dyslipidemia. Conclusion According to this nationwide longitudinal study, an elevated incidence rate of CHF was associated with OPLL.

Despite the widespread impact of the severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019, COVID-19) and vaccination in South Korea, our understanding of kidney diseases following these events remains limited. We aimed to address this gap by investigating the characteristics of glomerular diseases following the COVID-19 infection and vaccination in South Korea. Methods: Data from multiple centers were used to identify de novo glomerulonephritis (GN) cases with suspected onset following COVID-19 infection or vaccination. Retrospective surveys were used to determine the COVID-19–related histories of patients who were initially not implicated. Bayesian structural time series and autoregressive integrated moving average models were used to determine causality. Results: Glomerular diseases occurred shortly after the infection or vaccination. The most prevalent postinfection GN was podocytopathy (42.9%), comprising primary focal segmental glomerulosclerosis and minimal change disease, whereas postvaccination GN mainly included immunoglobulin A nephropathy (IgAN; 57.9%) and Henoch-Schönlein purpura nephritis (HSP; 15.8%). No patient progressed to end-stage kidney disease. Among the patients who were initially not implicated, nine patients with IgAN/HSP were recently vaccinated against COVID-19. The proportion of glomerular diseases changed during the pandemic in South Korea, with an increase in acute interstitial nephritis and a decrease in pauci-immune crescentic GN. Conclusion: This study showed the characteristics of GNs following COVID-19 infection or vaccination in South Korea. Understanding these associations is crucial for developing effective patient management and vaccination strategies. Further investigation is required to fully comprehend COVID-19’s impact on GN.

Purpose: For the treatment of locally advanced rectal cancer (LARC), research on primary lesions with mesorectal fascia (MRF) involvement is lacking. This study analyzed the clinical outcomes and efficacy of dose-escalated neoadjuvant concurrent chemoradiotherapy (NCRT) to patients with LARC involving MRF. Materials and Methods: We retrospectively reviewed 301 patients who were diagnosed with LARC involving MRF and underwent NCRT followed by total mesorectal excision (TME). Patients who received radiotherapy (RT) doses of ≤50.4 Gy were defined as the non-boost group, while ≥54.0 Gy as the boost group. Pathological tumor response and survival outcomes, including intrapelvic recurrence-free survival (IPRFS), distant metastases-free survival (DMFS) and overall survival (OS), were analyzed. Results: A total of 269 patients (89.4%) achieved a negative pathological circumferential resection margin and 104 (34.6%) had good pathological tumor regression grades. With a median follow-up of 32.4 months, IPRFS, DMFS, and OS rates at 5-years were 88.6%, 78.0%, and 91.2%, respectively. In the subgroup analysis by RT dose, the boost group included more advanced clinical stages of patients. For the non-boost group and boost group, 5-year IPRFS rates were 90.3% and 87.0% (p = 0.242), 5-year DMFS rates were 82.0% and 71.3% (p = 0.105), and 5-year OS rates were 93.0% and 80.6% (p = 0.439), respectively. Treatment related toxicity was comparable between the two groups (p = 0.211). Conclusion Although this retrospective study failed to confirm the efficacy of dose-escalated NCRT, favorable IPRFS and pathological complete response was achieved with NCRT followed by TME. Further studies combining patient customized RT dose with systemic therapies are needed.

Background: This study aimed to evaluate the annual trends of transfusion rates and utilization of blood management agents in total knee arthroplasty (TKA) based on the operation type and to analyze the risk factors of transfusion after TKA. Methods: Using the Korean National Insurance claims database of 797,106 primary and revision TKAs between January 2008 and October 2019, data on the patients’ characteristics, comorbidities, utilization of transfusion, and blood management agents were collected. The patients were categorized into three groups based on the operation type: primary, revision, and simultaneous bilateral TKA. The transfusion rate and utilization of blood management agents (intraoperative tranexamic acid [TXA] and preoperative iron supplements) were compared, and the risk factors for transfusion were evaluated. Results: After excluding the inaccurate data, 730,554 arthroplasties (636,292 primary, 10,540 revision, and 41,861 simultaneous bilateral TKAs) were identified. The transfusion rates of primary, revision, and simultaneous bilateral TKAs in 2019 were 64.0%, 67.7%, and 68.9%, respectively, which were significantly decreased compared with 83.2%, 88.0%, and 92.5% in 2008, respectively (p < 0.001). Conversely, the utilization of intraoperative TXA and preoperative iron supplements was significantly increased from 4.6% and 13.8%, respectively, in 2008 to 52.4% and 27.0%, respectively, in 2019 (p < 0.001). The utilization of intraoperative TXA and preoperative iron supplements significantly lowered the risk of transfusion after TKA (odds ratio [OR], 0.20; p < 0.001 and OR, 0.71; p < 0.001). Conclusions The transfusion rate after TKA decreased gradually from 83.5% to 64.5% between 2008 and 2019 in South Korea corresponding with the increased utilization of blood management agents. Therefore, consistent attention to patient blood management should be emphasized to reduce the transfusion rate after TKA.

Background: Surgical resection is the standard treatment for early-stage lung cancer. Since postoperative lung function is related to mortality, predicted postoperative lung function is used to determine the treatment modality. The aim of this study was to evaluate the predictive performance of linear regression and machine learning models. Methods: We extracted data from the Clinical Data Warehouse and developed three sets: set I, the linear regression model; set II, machine learning models omitting the missing data: and set III, machine learning models imputing the missing data. Six machine learning models, the least absolute shrinkage and selection operator (LASSO), Ridge regression, ElasticNet, Random Forest, eXtreme gradient boosting (XGBoost), and the light gradient boosting machine (LightGBM) were implemented. The forced expiratory volume in 1 second measured 6 months after surgery was defined as the outcome. Five-fold cross-validation was performed for hyperparameter tuning of the machine learning models. The dataset was split into training and test datasets at a 70:30 ratio. Implementation was done after dataset splitting in set III. Predictive performance was evaluated by R2 and mean squared error (MSE) in the three sets. Results: A total of 1,487 patients were included in sets I and III and 896 patients were included in set II. In set I, the R2 value was 0.27 and in set II, LightGBM was the best model with the highest R2 value of 0.5 and the lowest MSE of 154.95. In set III, LightGBM was the best model with the highest R2 value of 0.56 and the lowest MSE of 174.07. Conclusion The LightGBM model showed the best performance in predicting postoperative lung function.

Purpose: The purpose of this phase II trial was to evaluate whether the addition of simvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, to preoperative chemoradiotherapy (CRT) with capecitabine confers a clinical benefit to patients with locally advanced rectal cancer (LARC). Materials and Methods: Patients with LARC (defined by clinical stage T3/4 and/or lymph node positivity) received preoperative radiation (45-50.4 Gy in 25-28 daily fractions) with concomitant capecitabine (825 mg/m2 twice per day) and simvastatin (80 mg, daily). Curative surgery was planned 4-8 weeks after completion of the CRT regimen. The primary endpoint was pathologic complete response (pCR). The secondary endpoints included sphincter-sparing surgery, R0 resection, disease-free survival, overall survival, the pattern of failure, and toxicity. Results: Between October 2014 and July 2017, 61 patients were enrolled; 53 patients completed CRT regimen and underwent total mesorectal excision. The pCR rate was 18.9% (n=10) by per-protocol analysis. Sphincter-sparing surgery was performed in 51 patients (96.2%). R0 resection was achieved in 51 patients (96.2%). One patient experienced grade 3 liver enzyme elevation. No patient experienced additional toxicity caused by simvastatin. Conclusion The combination of 80 mg simvastatin with CRT and capecitabine did not improve pCR in patients with LARC, although it did not increase toxicity.

Objectives: . The impacts of ventilation tube (VT) type and effusion composition on the VT extrusion rate and complications in children with otitis media remain unclear. This part II study evaluated the factors affecting the extrusion rate, recurrence rate, and complications of VT insertion. Methods: . A prospective study was conducted between June 2014 and December 2016 (the EVENT study [analysis of the effectiveness of ventilation tube insertion in pediatric patients with chronic otitis media]), with follow-up data collected until the end of 2017. Patients aged <15 years diagnosed with otitis media with effusion who received VT insertion were recruited at 15 tertiary hospitals. The primary outcomes were time to extrusion of VT, time to effusion recurrence, and complications. Results: . Data from 401 patients were analyzed. After excluding the results of long-lasting tubes (Paparella type II and T-tubes), silicone tubes (Paparella type I) exhibited a significantly longer extended time to extrusion (mean, 400 days) than titanium tubes (collar-button-type 1.0 mm: mean, 312 days; P<0.001). VT material (hazard ratio [HR], 2.117, 95% confidence interval [CI], 1.254–3.572; P=0.005), age (HR, 3.949; 95% CI, 1.239–12.590; P=0.02), and effusion composition (P=0.005) were significantly associated with the time to recurrence of middle ear effusion. Ears with purulent (mean, 567 days) and glue-like (mean, 588 days) effusions exhibited a shorter time to recurrence than ears with serous (mean, 846 days) or mucoid (mean, 925 days) effusions. The revision VT rates during follow-up were 3.5%, 15.5%, 10.4%, and 38.9% in ears with serous, mucoid, glue-like, and purulent effusions, respectively (P<0.001). The revision surgery rates were higher among patients aged <7 years than among those aged ≥7 years. Conclusion . Silicone tubes (Paparella type I) were less prone to early extrusion than titanium 1.0 mm tubes. VT type, patient age, and effusion composition affected the time to recurrence of effusion.

The International IgA Nephropathy Prediction Tool has been recently developed to estimate the progression risk of immunoglobulin A nephropathy (IgAN). This study aimed to evaluate the clinical performance of this prediction tool in a large IgAN cohort in Korea. Methods: The study cohort was comprised of 2,064 patients with biopsy-proven IgAN from four medical centers between March 2012 and September 2021. We calculated the predicted risk for each patient. The primary outcome was occurrence of a 50% decline in estimated glomerular filtration rate (eGFR) from the time of biopsy or end-stage kidney disease. The model performance was evaluated for discrimination, calibration, and reclassification. We also constructed and tested an additional model with a new coefficient for the Korean race. Results: During a median follow-up period of 3.8 years (interquartile range, 1.8–6.6 years), 363 patients developed the primary outcome. The two prediction models exhibited good discrimination power, with a C-statistic of 0.81. The two models generally underestimated the risk of the primary outcome, with lesser underestimation for the model with race. The model with race showed better performance in reclassification compared to the model without race (net reclassification index, 0.13). The updated model with the Korean coefficient showed good agreement between predicted risk and observed outcome. Conclusion: In Korean IgAN patients, International IgA Nephropathy Prediction Tool had good discrimination power but underestimated the risk of progression. The updated model with the Korean coefficient showed acceptable calibration and warrants external validation.