Yu Seong Hwang

Background: Transitional care services (TCS) may reduce post-discharge readmissions and improve disease management in patients with chronic obstructive pulmonary disease (COPD). This study evaluated the cost-effectiveness of TCS using state-specific relative risks (RRs) derived from a randomized controlled trial (RCT). Methods: Between September 2022 and September 2024, 417 patients with COPD discharged from three university hospitals in South Korea were assigned to TCS (n = 210) or usual care (n = 207). State-specific RRs were derived from 3-month RCT outcomes and incorporated into a Markov model with 3-month cycles and a 10-year time horizon. Costs and quality-adjusted life-years (QALYs) were estimated for patients in their 60 s, 70 s, and 80 s. Deterministic sensitivity analysis (DSA) and probabilistic sensitivity analysis (PSA) were performed to assess parameter uncertainty. Results: In the base-case analysis, TCS increased costs by USD 2,128.91 and USD 1,133.41 per patient in the 60 s and 70 s cohorts, respectively, but reduced costs by USD 58.01 in the 80 s cohort. Incremental QALYs were 0.155, 0.195, and 0.271, respectively. The corresponding incremental cost-utility ratios were USD 13,709.60/QALY and USD 5,816.85/QALY in the 60 s and 70 s cohorts, while TCS was dominant in the 80 s cohort. DSA identified the RR of respiratory-disease readmission as the largest driver of uncertainty, followed by the RR of COPD readmission; the RR of other-disease readmission and TCS intervention cost were also influential. At a willingness-to-pay threshold of USD 23,050/QALY, the probabilities that TCS was cost-effective were 55.7%, 67.9%, and 82.7% for the 60 s, 70 s, and 80 s cohorts, respectively. Conclusions: This study evaluated the cost-effectiveness of TCS for patients with COPD using state-specific RRs derived from an RCT. TCS was cost-effective across all age cohorts, with more favourable economic outcomes observed in older patients and dominance in the 80 s cohort. These findings support the implementation of TCS for patients with COPD, while further research is needed to confirm its long-term clinical and economic benefits.

Objectives: Ischemic stroke is influenced by long-term metabolic and renal deterioration; however, many risk prediction frameworks rely on single time-point measurements. We examined whether multi-period patterns in national health screening indicators are associated with incident ischemic stroke in Korea.Methods: Using customized National Health Insurance Service data with 3 biennial screenings (P1: 2013–2014; P2: 2015–2016; P3: 2017–2018), we identified incident ischemic stroke during 2019–2023 (Korean Standard Classification of Diseases-7 I63). After applying eligibility criteria and excluding individuals with missing screening values, we performed 1:1 propensity score matching on sex, 1-year age strata, and insurance type (97 454 matched pairs; n=194 908). Multi-period indicators included waist circumference increase ≥10%, sustained blood pressure ≥130/80 mmHg, sustained fasting glucose ≥126 mg/dL, proteinuria progression, and creatinine elevation in ≥2 periods (sex-specific thresholds). Associations were evaluated using conditional logistic regression; a comparator model used P3-only indicators.Results: In the multi-period model, stroke was associated with waist circumference increase ≥10% (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01 to 1.08), sustained blood pressure ≥130/80 mmHg (OR, 1.34; 95% CI, 1.31 to 1.37), sustained fasting glucose ≥126 mg/dL (OR, 1.66; 95% CI, 1.60 to 1.73), creatinine elevation in ≥2 periods (OR, 1.08; 95% CI, 1.06 to 1.10), and proteinuria progression (OR, 1.36; 95% CI, 1.32 to 1.39). In the P3-only model, all single-time-point indicators were associated with incident stroke (ORs, 1.08 to 1.47).Conclusions: Multi-year patterns in metabolic screening indicators were associated with incident ischemic stroke. Repeated health screening measurements may complement single time-point assessments and support continuous risk-factor monitoring and patient-centered prevention.

The association between hospital readmission after ischemic stroke (IS) and long-term mortality remains insufficiently understood. This study examined the relationship between 90-day readmission and all-cause mortality over a 3-year follow-up period among patients experiencing their first IS. This retrospective cohort study used claims data from the National Health Insurance Service (NHIS) of South Korea. Patients discharged after hospitalization for IS between 2019 and 2020 were followed for 90 days to ascertain readmission status. Three readmission models were constructed based on clinical breadth: Model 1 (IS recurrence), Model 2 (IS and related diseases), and Model 3 (all-cause readmission). Propensity score-matched cohorts were analyzed using Kaplan-Meier methods and multivariable Cox proportional hazards models to assess associations with subsequent 3-year mortality. Among 22,548 patients included in the analysis, 83.3% (18,790) survived and 16.7% (3,758) died during the 3-year follow-up period. Kaplan-Meier analyses demonstrated significantly lower survival probabilities among patients readmitted within 90 days compared with those not readmitted across all three models (log-rank p < 0.05). In multivariable analyses, 90-day readmission was consistently associated with higher 3-year mortality (adjusted hazard ratio [aHR] range: 1.15-1.38). Higher mortality risk was observed among male patients (aHR ≈ 1.7), adults aged ≥ 80 years (aHR ≈ 5.3), and underweight individuals with body mass index < 18.5 kg/m² (aHR ≈ 2.0). In contrast, engagement in light physical activity and moderate-to-vigorous exercise was associated with lower mortality risk (aHR ≈ 0.74-0.78). Hospital readmission within 90 days after ischemic stroke was consistently associated with increased long-term mortality. In this observational study, early readmission may serve as a marker of clinical vulnerability, and the findings support the potential value of structured, stroke-specific transitional care models aimed at reducing avoidable readmissions. Implementing tailored transitional care interventions at discharge may help identify high-risk patients early and support continuity of care, thereby potentially mitigating adverse long-term outcomes after ischemic stroke.

Background: Transitioning from hospital to home presents substantial challenges for patients with chronic obstructive pulmonary disease (COPD), often leading to difficulties maintaining self-management, functional independence, and psychological well-being after discharge. Although transitional care programs are increasingly implemented, their effects on multidimensional patient-centered outcomes remain insufficiently examined. This study aimed to evaluate the effectiveness of a nurse-coordinated transitional care service for patients with COPD during the transition from hospital to home and to examine its broader implications for improving continuity of care and patient-centered outcomes within the healthcare system. Methods: This randomized controlled trial was conducted in three university hospitals in South Korea between November 2022 and December 2024. A total of 465 patients were randomly assigned to either a nurse-coordinated transitional care intervention group or a usual care group. The intervention included structured self-management education during hospitalization, post-discharge home visits, and follow-up telephone consultations during the first month after discharge. Outcomes were assessed at baseline, 1 month, and 3 months. Statistical analyses included linear mixed-effects models for continuous outcomes and chi-square tests and independent t-tests for group comparisons. Results: Patients in the Transitional Care Group (TCG) showed marked improvements: disease awareness increased from 27.9% to 94.3% (vs. 35.7% in the Usual Care Group [UCG], RR = 2.64, 95% CI: 2.19–3.18, p < 0.001) and exercise adherence to 76.3% (vs. 43.0%, RR = 1.78, 95% CI: 1.49–2.11, p < 0.001). After adjusting for age, cognitive function declined in both groups but showed significantly smaller decreases in the TCG than in the UCG at 3 months (mean difference = −0.92, p < 0.001), and IADL demonstrated significantly better preservation in the TCG (mean difference = −1.77, p < 0.001). Self-efficacy declined in both groups but remained significantly higher in the TCG (mean difference = 2.65, p < 0.001). Anxiety and depression were significantly reduced in the TCG compared with the UCG (anxiety: −1.45, p < 0.001; depression: −2.72, p < 0.001). After adjusting for age, discharge preparedness and post-discharge management capacity were significantly higher in the TCG than in the UCG (adjusted mean differences = 3.25 and 4.93, respectively; both p < 0.001). Conclusions: These findings indicate that nurse-coordinated transitional care enhances patients’ self-management capacity and improves patient-centered outcomes during the transition from hospital to home.

Background: Online patient communities accumulate a large volume of user-generated narratives regarding symptoms, treatment decisions, rehabilitation, caregiving, and administrative processes. Systematically characterizing these narratives may provide patient-centered insights that complement conventional clinical and survey-based research. This study aimed to identify and interpret major themes discussed in a South Korean online community for patients with brain diseases, with a focus on ischemic stroke (cerebral infarction), spontaneous intracerebral hemorrhage, and cerebral aneurysm. Methods: A retrospective cross-sectional text-mining study was conducted on posts and associated comments published from October 1, 2024, to March 31, 2025, in a large Naver Cafe community. Posts were archived as PDF files, converted into text, and merged into a single corpus. Korean-language preprocessing was performed using the KoNLPy package with the MeCab morphological analyzer. Latent Dirichlet allocation (LDA) topic models were fitted across candidate numbers of topics. The final model was selected using quantitative metrics (including coherence and perplexity) and interpretability. Topic interpretation and labeling were supported by pyLDAvis keyword relevance weighting (λ=0.6) and expert review. Results: After preprocessing, the final corpus comprised 5,298 posts (including comments) and 20,474 unique tokens. The optimal LDA solution identified 12 topics clustered into four broad domains: (i) clinical management and secondary prevention, (ii) recovery and rehabilitation, (iii) inpatient care and caregiving, and (iv) psychosocial and administrative needs. Conclusion: Unsupervised topic modeling of online community discussions delineated a coherent set of patient- and caregiver-expressed needs that extend beyond clinical recovery to include caregiving burden and navigation of administrative and financial support systems.

Background: This study aimed to systematically review randomized controlled trials evaluating the effectiveness of web- and app-based health management interventions for patients at high risk of stroke, including those with cardiovascular disease, type 2 diabetes, or obesity. Clinical outcomes (blood pressure and glycated hemoglobin), self-management knowledge, health behaviors, and quality of life were examined. Methods: Following PRISMA guidelines, we searched PubMed, Web of Science, CINAHL, and the Cochrane Library for randomized controlled trials published between January 2010 and December 2024. Search terms included combinations of “Hypertension,” “Diabetes Mellitus,” “Myocardial Infarction,” “Obesity,” “Mobile Applications,” and “Web-Based Intervention.” Studies that provided sufficient data for quantitative synthesis were included in the meta-analysis. Pooled effect sizes were calculated using RevMan 5.4, and subgroup analyses were conducted based on intervention duration. Results: Thirty-five studies met the inclusion criteria. Meta-analysis revealed that web- and app-based interventions significantly improved blood pressure, glycated hemoglobin level, and medication adherence among individuals at high risk of stroke. These interventions also enhanced quality of life and increased self-management knowledge and behaviors. Subgroup analyses of web- or app-based educational programs indicated that clinical indicators improved with interventions lasting 3 months, whereas self-management knowledge, behaviors, and depression symptoms showed significant improvements with 6-month interventions. Conclusion: This study demonstrates that web- and app-based health management interventions yield improvements in clinical, psychological, and behavioral outcomes for patients at high risk of stroke. These findings provide evidence for the development and implementation of tailored digital health interventions for effective stroke prevention and chronic disease management.

Background: Cardiovascular and cerebrovascular diseases significantly contribute to global mortality and disability. The shift to outpatient postoperative care, accelerated by the COVID-19 pandemic, emphasizes the need for effective management of postoperative outcomes. The high rates of cardiovascular and cerebrovascular diseases in Korea necessitate focused transitional care during patient discharge periods. However, limited research exists on the postoperative experiences of discharged patients, underscoring the necessity of establishing evidence-based services to optimize transitional care. Objective: The objective of this paper was to analyze the emotional experiences of patients who underwent cardiovascular and cerebrovascular surgeries using data from Naver, a major South Korean web portal. Methods: Posts were collected using specific keywords and processed with the Korean Bidirectional Encoder Representations from Transformers (KoBERT) model based on Transformer, which classified sentiments into positive, neutral, and negative categories. Model performance was validated according to precision, recall, F₁-score, and support. Sentiment analysis was conducted within the Transitional Care Model (TCM) framework, divided into 5 domains: health status, care resources, care demand, interaction, and mental state. Results: The KoBERT model demonstrated high classification performance, achieving a precision of 96%, recall of 94%, and an F₁-score of 94%. Sentiment analysis revealed that compared with cardiovascular surgery patients, cerebrovascular surgery patients experienced higher negative emotions regarding health status, whereas cardiovascular surgery patients expressed more negative sentiments in care demands. Conclusions: Different patient groups experience distinct emotional and practical challenges postdischarge. Particularly, keywords within the TCM framework highlight that cerebrovascular surgery patients require robust rehabilitation and caregiver support, whereas cardiovascular surgery patients need better cost management. These findings underscore the importance of personalized transitional care strategies tailored for cardiovascular and cerebrovascular diseases. The insights derived from this study can guide health care policymakers in designing more targeted and patient-centered interventions to improve postdischarge care and patient-centered transitional care, ensuring continuous and effective postoperative management.

Chronic obstructive pulmonary disease (COPD) stems from airflow blockage and lung damage, and indoor air pollution exacerbates COPD, underscoring the necessity for proactive management. Older COPD patients, prone to respiratory and heat-related issues, require crucial assistance, yet their reduced awareness necessitates ongoing education to identify and enhance indoor air quality. To tackle this challenge, we developed a socially assistive robot (SAR) integrating IoT air quality sensors to guide patients in improving indoor air quality (IAQ). This study evaluated IAQ enhancement among older COPD patients using this technology, uncovering a significant reduction in ‘poor air quality alerts’ with a clear linear trend. Although ‘good alerts’ remained consistent, machine learning models predicted improved air quality post-alerts. Consistent alerts serve as a motivating factor for patients to maintain IAQ standards. However, barriers to SAR utilization, such as psychological and operational hurdles, need to be addressed in future research endeavors.

Background: Chronic obstructive pulmonary disease (COPD) is associated with a high readmission rate and poses a significant disease burden. South Korea initiated pilot projects on transitional care services (TCS) to reduce readmissions. However, evidence from cost-effectiveness analyses remains undiscovered. This study aimed to evaluate the cost-effectiveness of TCS in patients with COPD from the healthcare system’ perspective. Method: A cost-utility analysis was conducted using a Markov model containing six components of possible medical use after discharge. Transition probabilities and medical costs were extracted from the National Health Insurance Service Senior Cohort (NHIS-SC), and utility data were obtained from published literature. Sensitivity analyses were performed to test the robustness of the results. Results: Conducting TCS produced an incremental quality-adjusted life years gain of 0.231, 0.275, 0.296 for those in their 60s, 70s, and 80s, respectively, and cost savings of $225.16, $1668, and $2251.64 for those in their 60s, 70s, and 80s, respectively, per patient over a 10-year time horizon. The deterministic sensitivity analysis indicated that the TCS cost and the cost of readmission by other diseases immensely impact the results. The probabilistic sensitivity analyses showed that the probability that the incremental cost-effectiveness ratio is below $23,050 was over 85%, 93%, and 97% for those in the 60s, 70s, and 80s, respectively. Conclusions: TCS was the dominant option compared to usual care. However, it is advantageous to the healthcare budget preferentially consider patients aged over 70 years with severe TCS symptoms. In addition, it is essential to include the management of underlying comorbidities in TCS intervention. Trial registration: Clinical Research Information Service (CRIS), KCT0007937. Registered on 24 November 2022

Objectives: The high readmission rate of patients with chronic obstructive pulmonary disease (COPD) has led to the worldwide establishment of proactive measures for identifying and mitigating readmissions. This study aimed to identify factors associated with readmission, as well as groups particularly vulnerable to readmission that require transitional care services.Methods: To apply transitional care services that are compatible with Korea’s circumstances, targeted groups that are particularly vulnerable to readmission should be identified. Therefore, using the National Health Insurance Service’s Senior Cohort database, we analyzed data from 4874 patients who were first hospitalized with COPD from 2009 to 2019 to define and analyze readmissions within 30 days after discharge. Logistic regression analysis was performed to determine factors correlated with readmission within 30 days.Results: The likelihood of readmission was associated with older age (for individuals in their 80s vs. those in their 50s: odds ratio [OR], 1.59; 95% confidence interval [CI], 1.19 to 2.12), medical insurance type (for workplace subscribers vs. local subscribers: OR, 0.84; 95% CI, 0.72 to 0.99), type of hospital (those with 300 beds or more vs. fewer beds: OR, 0.77; 95% CI, 0.66 to 0.90), and healthcare organization location (provincial areas vs. the capital area: OR, 1.66; 95% CI, 1.14 to 2.41).Conclusions: Older patients, patients holding a local subscriber insurance qualification, individuals admitted to hospitals with fewer than 300 beds, and those admitted to provincial hospitals are suggested to be higher-priority for transitional care services.