In the 2023–2024 season, the influenza epidemic in South Korea peaked earlier than in recent years. In this study, we aimed to estimate the interim vaccine effectiveness (VE) of the influenza vaccination to prevent influenza during the early season. From November 1, 2023, to December 31, 2023, we enrolled 2,632 subjects with influenza-like illness from eight hospitals participating in hospital-based influenza morbidity and mortality surveillance. A retrospective test-negative case-control study was conducted to estimate the VE. The results showed an adjusted VE of 22.5% (95% confidence interval [CI], 6.6 to 35.8) for the total population. The adjusted VE was 22.3% (95% CI, 6.1 to 35.7) for influenza A and 9.4% (95% CI, −51.3 to 45.7) for influenza A/H1N1. Full results of the analysis will be reported.

Background: Bivalent booster mRNA vaccines containing the omicron-variant strains have been introduced worldwide in the autumn of 2022. Nevertheless, the omicron subvariants evoked another large coronavirus disease 2019 (COVID-19) pandemic wave in late 2022 and early 2023. Methods: A retrospective, test-negative, case-control study was conducted to estimate the vaccine effectiveness (VE) of bivalent COVID-19 vaccines in 8 university hospitals between January and February 2023. The case and control groups were divided based on nasopharyngeal COVID-19 real-time polymerase chain reaction results and matched based on age, sex, hospital, and date (week) of the test performed. The VE of the BA.1- or BA.4/BA.5-based mRNA vaccines were estimated. VE was calculated using the 1−adjusted odds ratio from multivariable logistic regression. Results: In total, 949 patients and 947 controls were enrolled in this study. VE for the BA.4/ BA.5-based bivalent mRNA vaccine was 43% (95% confidence interval [CI], 17, 61%). In subgroup analysis based on age and underlying medical conditions, BA.4/BA.5-based bivalent mRNA vaccine was effective against old adults aged ≥ 65-years (VE, 55%; 95% CI, 23, 73%) and individuals with comorbidities (VE, 54%; 95% CI, 23, 73%). In comparison, the BA.1-based bivalent mRNA vaccine did not demonstrate statistically significant effectiveness (VE, 25%; 95% CI, −8, 49%). Conclusion The BA.4/BA.5-based bivalent mRNA booster vaccine provided significant protection against COVID-19 in the Korean adults, especially in the older adults aged ≥ 65 years and in individuals with underlying medical conditions.

Background: Psoriasis imposes a significant treatment burden on patients, particularly impacting well-being and quality of life (QoL). The psychosocial impact of psoriasis treatments remains unexplored in most patient populations. Objective: To assess the impact of adalimumab on health-related QoL (HRQoL) in Korean patients with psoriasis. Methods: This 24-week, multicenter, observational study, assessed HRQoL in Korean patients treated with adalimumab in a real-world setting. Patient-reported outcomes (PROs) including European Quality of Life-5 Dimension scale (EQ-5D), EQ-5D VAS, SF-36, and DLQI were evaluated at week 16 and 24, versus baseline. Patient satisfaction was assessed using TSQM. Results: Among 97 enrolled patients, 77 were assessed for treatment effectiveness. Most patients were male (52, 67.5%) and mean age was 45.4 years. Median baseline body surface area and Psoriasis Area and Severity Index (PASI) scores were 15.00 (range 4.00~80.00) and 12.40 (range 2.70~39.40), respectively. Statistically significant improvements in all PROs were observed between baseline and week 24. Mean EQ-5D score improved from 0.88 (standard deviation [SD], 0.14) at baseline to 0.91 (SD, 0.17) at week 24 (p=0.0067). The number of patients with changes in PASI 75, 90, or 100 from baseline to week 16 and 24 were 65 (84.4%), 17 (22.1%), and 1 (1.3%); and 64 (83.1%), 21 (27.3%), and 2 (2.6%), respectively. Overall treatment satisfaction was reported, including effectiveness and convenience. No unexpected safety findings were noted. Conclusion Adalimumab improved QoL and was well-tolerated in Korean patients with moderate to severe psoriasis, as demonstrated in a real-world setting. Clinical trial registration number (clinicaltrials.gov: NCT03099083).

Purpose: Rapid sequence intubation (RSI) using sedatives and neuromuscular blocking agents (NMBAs) is recommended for pediatric emergency endotracheal intubation (ETI), but is not frequently performed in Korea. This study aimed to verify factors associated with the underuse of RSI medications. Materials and Methods: This multicenter retrospective study reviewed patients aged under 18 years who underwent an ETI within 24 hours of arrival at the emergency department between 2016 and 2019. Any cases of ETI during cardiopulmonary resuscitation were excluded. We investigated the characteristics of the patients, intubators, RSI medications, and outcomes. The study cases were classified into no-medication, sedative-only, and sedative-with-NMBA groups. Multivariable logistic regression analysis of RSI medication use was conducted. Results: A total of 334 cases with a median age of 3.4 years were included in this study. Sedatives and NMBAs were used in 63.8% and 32.9%, respectively. In comparing the no-medication (n=121), sedative-only (n=103), and sedative-with-NMBA (n=110) groups, patient age (median; 1.0 year vs. 2.8 years vs. 11.3 years; p<0.001), underlying medical conditions (77.7% vs. 56.3% vs. 36.4%; p<0.001), and pediatricians as intubators (76.9% vs. 54.4% vs. 17.3%; p<0.001) were different. The factors that influenced sedatives with NMBA use were patient age [for a year increment; adjusted odds ratio (aOR), 1.182; 95% confidence interval (CI), 1.120– 1.249], no underlying medical conditions (aOR, 2.109; 95% CI, 1.093–4.070), and intubators other than pediatricians (aOR, 5.123; 95% CI, 2.257–11.626). Conclusion RSI accounted for 32.9% of pediatric emergency ETI in Korea. The underuse of RSI medications is associated with younger patient age, underlying medical conditions, and pediatricians as intubators.

Purpose: In this trial, we investigated the efficacy and safety of adjuvant letrozole for hormone receptor (HR)-positive breast cancer. Here, we report the clinical outcome in postmenopausal women with HR-positive breast cancer treated with adjuvant letrozole according to estrogen receptor (ER) expression levels. Methods: In this multi-institutional, open-label, observational study, postmenopausal patients with HR-positive breast cancer received adjuvant letrozole (2.5 mg/daily) for 5 years unless they experienced disease progression or unacceptable toxicity or withdrew their consent. The patients were stratified into the following 3 groups according to ER expression levels using a modified Allred score (AS): low, intermediate, and high (AS 3–4, 5–6, and 7–8, respectively). ER expression was centrally reviewed. The primary objective was the 5-year disease-free survival (DFS) rate. Results: Between April 25, 2010, and February 5, 2014, 440 patients were enrolled. With a median follow-up of 62.0 months, the 5-year DFS rate in all patients was 94.2% (95% confidence interval [CI], 91.8–96.6). The 5-year DFS and recurrence-free survival (RFS) rates did not differ according to ER expression; the 5-year DFS rates were 94.3% and 94.1%in the low-to-intermediate and high expression groups, respectively (p = 0.6), and the corresponding 5-year RFS rates were 95.7% and 95.4%, respectively (p = 0.7). Furthermore, 25 patients discontinued letrozole because of drug toxicity. Conclusion Treatment with adjuvant letrozole showed very favorable treatment outcomes and good tolerability among Korean postmenopausal women with ER-positive breast cancer, independent of ER expression.

Background: Patient-centered management is becoming increasingly important in gout, but there are limited studies exploring patients' perspectives and preferences. We aimed to investigate patients' perspectives and preferences regarding gout and gout management, and their impacts on adherence to urate lowering therapy (ULT). Methods: A paper-based survey was performed in patients with gout seen at the rheumatology outpatient clinics of 16 tertiary hospitals. The survey included questions regarding demographics, comorbidities, gout attacks, current treatment and adherence, and patients' perspectives and preferences regarding gout and gout management. Multivariate regression analysis was performed to determine the factors associated with ULT adherence. Results: Of 809 surveyed patients with gout, 755 (94.5%) were using ULT. Among those using ULT, 89.1% had ≥ 80% adherence to ULT. Majority of the patients knew management strategies to some extent (94.8%), perceived gout as a life-long disease (91.2%), and were making efforts toward practicing at least one lifestyle modification (89.2%). Most patients (71.9%) obtained information about gout management during their clinic visits.Approximately half of the patients (53.6%) preferred managing their disease with both ULT and lifestyle modification, 28.4% preferred ULT only, and 17.4% preferred lifestyle modification only. Adherence was better in patients with older age (odds ratio [OR], 1.03), those with better knowledge of gout management strategies (OR, 3.56), and those who had preference for ULT (OR, 2.07). Conclusion Patients' perspectives and management preferences had high impacts on adherence to ULT in gout. Consideration of patients' perspectives and preferences is important for achieving the desired clinical outcome in gout.

Background: Psoriasis is a chronic disease that can have accompanying comorbidities including arthritis, metabolic syndrome, and cardiovascular diseases. Patients with psoriasis tend to frequently visit medical institutions, and their economic burden for medical services is high. Objective: To investigate the economic burden of psoriasis in Korea. Methods: The Korean Society for Psoriasis conducted a multi-center field survey of the patients and analyzed the national insurance claim data. Also, we discussed the medical environment of psoriasis in Korea based on the results. Results: The economic burden of psoriasis patients is substantial and varied by the type of medical institute. Patients also paid the indirect and intangible medical costs. Biological agents, which is used in patients with severe psoriasis, led to an increase in the cost. Conclusion This is the first study to estimate the economic burden of psoriasis in Korea comprehensively. To improve the medical environment of psoriasis and alleviate the burden of patients, discussion on the more efficient health policy and medical insurance criteria for psoriasis would be needed.

Purpose: The aim of this study was to show that bariatric surgery (BS) is more effective than medical therapy (MT) in Asian obese patients. Methods: In this prospective, multicenter, nonrandomized, controlled trial, obese patients with body mass index of ≥35 kg/m2 or 30.0–34.9 kg/m2 with obesity-related comorbidities were assigned to undergo BS, such as laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass, or MT. Patients who underwent BS were evaluated 4, 12, 24, and 48 weeks after surgery, whereas patients who received MT were monitored at a hospital every 6 weeks for 1 year. At each visit, weight, waist and hip circumference, and blood pressure were measured, and patients underwent physical examination and laboratory testing. Health-related quality of life (HQOL) was investigated using Euro QOL-5 Dimension, Impact of Weight on Quality of Life questionnaire-Lite and Obesity-related Problems scale. Results: The study included 264 patients from 13 institutions; of these, 64 underwent BS and 200 received MT. Of the patients who underwent BS, 6.3% experienced early complications. Relative weight changes from baseline to 48 weeks were significantly greater in the BS than in the MT group (26.9% vs. 2.1%, P < 0.001), as were the rates of remission of diabetes (47.8% vs. 16.7%, P = 0.014), hypertension (60.0% vs. 26.1%, P < 0.001), and dyslipidemia (63.2% vs. 22.0%, P < 0.001). HQOL was better in the BS than in the MT group at 48 weeks. Conclusion BS was safe and effective in Korean obese patients, with greater weight reduction, remission of comorbidities, and quality of life improvement than MT.