A fundamental objective of public health is to identify the causes of diseases and associated risk factors to develop effective prevention strategies. In this regard, the population attributable fraction (PAF) has become a key epidemiological measure for quantifying the proportion of disease incidence in a population attributable to specific risk factors.Current Concepts: The concept of PAF is widely applied in epidemiological and public health research, playing a crucial role in prioritizing disease prevention and management strategies. Estimating the PAF of cancer risk factors based on national data provides essential evidence for the formulation of government-led cancer control policies and prevention strategies. In particular, these estimates serve as critical indicators for evaluating cancer control programs and informing policy decisions. Given the variations in risk factor prevalence across different populations, it is crucial to estimate PAF using country-specific data to ensure the development of tailored and effective public health interventions.Discussion and Conclusion: This study underscores the importance of PAF as a foundational tool for evidencebased policymaking and highlights the need for periodic reassessment to enhance the effectiveness of cancer prevention and control efforts.

A fundamental objective of public health is to identify the causes of diseases and associated risk factors to develop effective prevention strategies. In this regard, the population attributable fraction (PAF) has become a key epidemiological measure for quantifying the proportion of disease incidence in a population attributable to specific risk factors.Current Concepts: The concept of PAF is widely applied in epidemiological and public health research, playing a crucial role in prioritizing disease prevention and management strategies. Estimating the PAF of cancer risk factors based on national data provides essential evidence for the formulation of government-led cancer control policies and prevention strategies. In particular, these estimates serve as critical indicators for evaluating cancer control programs and informing policy decisions. Given the variations in risk factor prevalence across different populations, it is crucial to estimate PAF using country-specific data to ensure the development of tailored and effective public health interventions.Discussion and Conclusion: This study underscores the importance of PAF as a foundational tool for evidencebased policymaking and highlights the need for periodic reassessment to enhance the effectiveness of cancer prevention and control efforts.

A fundamental objective of public health is to identify the causes of diseases and associated risk factors to develop effective prevention strategies. In this regard, the population attributable fraction (PAF) has become a key epidemiological measure for quantifying the proportion of disease incidence in a population attributable to specific risk factors.Current Concepts: The concept of PAF is widely applied in epidemiological and public health research, playing a crucial role in prioritizing disease prevention and management strategies. Estimating the PAF of cancer risk factors based on national data provides essential evidence for the formulation of government-led cancer control policies and prevention strategies. In particular, these estimates serve as critical indicators for evaluating cancer control programs and informing policy decisions. Given the variations in risk factor prevalence across different populations, it is crucial to estimate PAF using country-specific data to ensure the development of tailored and effective public health interventions.Discussion and Conclusion: This study underscores the importance of PAF as a foundational tool for evidencebased policymaking and highlights the need for periodic reassessment to enhance the effectiveness of cancer prevention and control efforts.

OBJECTIVES: Clinical studies have suggested an association between migraine and the occurrence of Parkinson’s disease (PD). However, it is unknown whether migraine affects PD risk. We aimed to investigate the incidence of PD in patients with migraine and to determine the risk factors affecting the association between migraine and PD incidence. METHODS: Using the Korean National Health Insurance System database (2002-2019), we enrolled all Koreans aged ≥40 years who participated in the national health screening program in 2009. International Classification of Diseases (10th revision) diagnostic codes and Rare Incurable Diseases System diagnostic codes were used to define patients with migraine (within 12 months of enrollment) and newly diagnosed PD. RESULTS: We included 214,193 patients with migraine and 5,879,711 individuals without migraine. During 9.1 years of follow-up (55,435,626 person-years), 1,973 (0.92%) and 30,664 (0.52%) individuals with and without migraine, respectively, were newly diagnosed with PD. Following covariate adjustment, patients with migraine showed a 1.35-fold higher PD risk than individuals without migraine. The incidence of PD was not significantly different between patients with migraine with aura and those without aura. In males with migraine, underlying dyslipidemia increased the risk of PD (p=0.012). In contrast, among females with migraine, younger age (<65 years) increased the risk of PD (p=0.038). CONCLUSIONS Patients with migraine were more likely to develop PD than individuals without migraine. Preventive management of underlying comorbidities and chronic migraine may affect the incidence of PD in these patients. Future prospective randomized clinical trials are warranted to clarify this association.

Purpose: : This study aimed to explore and describe intensive care unit (ICU) nurses’ experience of clinical adaptation. Methods: : The participants were 14 ICU nurses with more than two years of working experience in the ICU. Data were collected through in-depth individual interviews conducted between July and October 2021. Theoretical sampling was used to the point of theoretical saturation. Data were analyzed using the Strauss and Corbin method. Results: : A total of 79 concepts, 37 subcategories, and 16 categories were identified through open coding. Axial coding based on the paradigm model revealed that the central phenomenon was “The harsh adversity faced in the nursing field where life and death are determined” and the core category was “Enduring the adversity of caring for critically ill patients and achieving self-realization.” ICU nurses’ clinical adaptation process was explained in five phases: “confrontation period,” “turbulent period,” “seeking period,” “struggling period,” and “stabilized period.” The five phases that affect interventional conditions were “Support from reliable people,” “Recognition of administrative and financial support.” Conclusion : This study provided novel insights for a comprehensive understanding of ICU nurses’ clinical adaptation processes. Furthermore, the findings are expected to be used as basic data to develop multifaceted strategies to help ICU nurses’ adaptation to critical care.

Objectives: In this study, we aimed to compare the genetic architecture of schizophrenia (SCZ) and bipolar disorder (BD) in a Korean population by analyzing polygenic risk scores (PRS) derived from large-scale psychiatric disorder genome-wide association study data, based on genetic information collected from SCZ, BD, and healthy control groups. Methods: The study included 713 Korean patients with SCZ, 1,317 with BD, 526 healthy controls. Genotyping was performed using the Korean Biobank Array. PRS-continuous shrinkage method was used to calculate the PRS. Analysis of covariance (ANCOVA) was conducted to determine the association between SCZ or BD disorder and PRS after adjusting for sex. Results: ANCOVA revealed significant differences in PRS values by diagnosis for PRS for SCZ (F=215.281, p<0.001), PRS for BD (F=13.811, p<0.001), and PRS for major depressive disorder (F=6.042, p=0.002). Post-hoc analysis showed that PRS for SCZ was highest in SCZ, followed by BD, and healthy controls. PRS for BD was elevated in both BD and SCZ compared to healthy controls. Conclusion Our study revealed quantitative differences in genetic architecture between SCZ and BD compared to healthy controls, while also suggesting a shared genetic background between the two disorders.

Objective: : The effectiveness of gamma knife radiosurgery (GKR) in the treatment of brain metastases is well established. The aim of this study was to evaluate the efficacy and safety of maximizing the radiation dose in GKR and the factors influencing tumor control in cases of small and medium-sized brain metastases from non-small cell lung cancer (NSCLC). Methods: : We analyzed 230 metastatic brain tumors less than 5 mL in volume in 146 patients with NSCLC who underwent GKR. The patients had no previous radiation therapy for brain metastases. The pathologies of the tumors were adenocarcinoma (n=207), squamous cell carcinoma (n=18), and others (n=5). The radiation doses were classified as 18, 20, 22, and 24 Gy, and based on the tumor volume, the tumors were categorized as follows : small-sized (less than 1 mL) and medium-sized (1–3 and 3–5 mL). The progression-free survival (PFS) of the individual 230 tumors and 146 brain metastases was evaluated after GKR depending on the pathology, Eastern Cooperative Oncology Group (ECOG) performance score (PS), tumor volume, radiation dose, and anti-cancer regimens. The radiotoxicity after GKR was also evaluated. Results: : After GKR, the restricted mean PFS of individual 230 tumors at 24 months was 15.6 months (14.0–17.1). In small-sized tumors, as the dose of radiation increased, the tumor control rates tended to increase (p=0.072). In medium-sized tumors, there was no statistically difference in PFS with an increase of radiation dose (p=0.783). On univariate analyses, a statistically significant increase in PFS was associated with adenocarcinomas (p=0.001), tumors with ECOG PS 0 (p=0.005), small-sized tumors (p=0.003), radiation dose of 24 Gy (p=0.014), synchronous lesions (p=0.002), and targeted therapy (p=0.004). On multivariate analyses, an improved PFS was seen with targeted therapy (hazard ratio, 0.356; 95% confidence interval, 0.150–0.842; p=0.019). After GKR, the restricted mean PFS of brain at 24 months was 9.8 months (8.5–11.1) in 146 patients, and the pattern of recurrence was mostly distant within the brain (66.4%). The small and medium-sized tumors treated with GKR showed radiotoxicitiy in five out of 230 tumors (2.2%), which were controlled with medical treatment. Conclusion : The small-sized tumors were effectively controlled without symptomatic radiation necrosis as the radiation dose was increased up to 24 Gy. The medium-sized tumors showed potential for symptomatic radiation necrosis without signifcant tumor control rate, when greater than 18 Gy. GKR combined targeted therapy improved the tumor control of GKR-treated tumors.

Background: Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy. Methods: This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 μIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 μIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years. Conclusion The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.

Objectives: This study examined whether the polygenic risk score (PRS) calculated from the most recent genome-wide association study for bipolar disorder (BD) of European ancestry patients is significantly associated with BD diagnosis in the Korean population. Methods: The study included 417 Korean patients with BD and 497 healthy controls. Genotyping was performed using the Korean Biobank Array. Summary statistics of the European samples from the Psychiatric Genomic Consortium were used as base data to generate the PRS for each individual. The program PRSice-2 was used to calculate the PRS. Logistic regression was conducted to determine the association between BD diagnosis and PRS for BD after adjusting for age and sex. Results: PRS for BD was significantly higher in patients diagnosed with BD compared to healthy controls. The PRS at the p-value threshold of 0.01 best explained the variance of BD after adjusting for age and sex (R2 =0.0061, p=0.039). Subgroup analyses were performed for bipolar I and II subgroups. In bipolar I patients, the PRS at the p-value threshold of 0.01 best explained the diagnosis (R2 =0.0165, p=0.0055), whereas no significant result was found for bipolar II patients. Conclusion PRS for BD calculated for the Korean sample showed a significant association with the BD diagnosis. This result suggests an overlapping genetic risk for BD between the European and Korean populations.

Background: Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy. Methods: This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 μIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 μIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years. Conclusion The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.