There have been few studies that comprehensively evaluated factors affecting immune responses and the correlation between humoral and cellular immune responses after vector, mix-and-match, and mRNA vaccines against SARS-CoV-2. Therefore, we analyzed the effects of age, sex, and the different vaccine regimens on the immune responses to vaccination against SARS-CoV-2.

Background/Objectives: Data availability can affect the performance of AI-based early warning scores (EWSs). This study evaluated how the extent of missing data and imputation strategies influence the predictive performance of the VitalCare–Major Adverse Event Score (VC-MAES), an AI-based EWS that uses last observation carried forward and normal-value imputation for missing values, to forecast clinical deterioration events, including unplanned ICU transfers, cardiac arrests, or death, up to 6 h in advance. Methods: We analyzed real-world data from 6039 patient encounters at Keimyung University Dongsan Hospital, Republic of Korea. Performance was evaluated under three scenarios: (1) using only vital signs and age, treating all other variables as missing; (2) reintroducing a full set of real-world clinical variables; and (3) imputing missing values drawn from a distribution within one standard deviation of the observed mean or using Multiple Imputation by Chained Equations (MICE). Results: VC-MAES achieved the area under the receiver operating characteristic curve (AUROC) of 0.896 using only vital signs and age, outperforming traditional EWSs, including the National Early Warning Score (0.797) and the Modified Early Warning Score (0.722). Reintroducing full clinical variables improved the AUROC to 0.918, whereas mean-based imputation or MICE decreased the performance to 0.885 and 0.827, respectively. Conclusions: VC-MAES demonstrates robust predictive performance with limited inputs, outperforming traditional EWSs. Incorporating actual clinical data significantly improved accuracy. In contrast, mean-based or MICE imputation yielded poorer results than the default normal-value imputation, potentially due to disregarding the “informative presence” embedded in missing data patterns. These findings underscore the importance of understanding missingness patterns and employing imputation strategies that consider the decision-making context behind data availability to enhance model reliability.

Objective: The heterogeneous nature of sepsis renders determining its underlying causes difficult, which may delay diagnosis and intervention. VitalCare-SEPsis Score (VC-SEPS) is a deep learning-based algorithm that predicts sepsis and monitors patient conditions based on electronic medical record data. However, few studies have prospectively compared medical artificial intelligence software algorithms and traditional scoring systems to predict sepsis. This prospective observational study attempted to validate the predictive performance and risk stratification of VC-SEPS for early prediction of sepsis. Methods: In this prospective observational study, we collected electronic medical record data from 6,797 patients hospitalised at Keimyung University Dongsan Hospital, Daegu, South Korea. The final version of the analysed set included 6,455 patients, 325 of whom were diagnosed with sepsis. Results: The area under the receiver operating characteristic curve of VC-SEPS was 0.880, indicating its superiority over traditional scoring systems. The algorithm performance showed a consistent trend within 24 hours. On patients’ initial admission, the VC-SEPS was associated with the risk of developing sepsis, and the score accurately predicted sepsis by an average of 68.05 min compared with diagnosis time by an operational definition of sepsis. Discussion: VC-SEPS could assist medical staff with early diagnosis and intervention in clinical practice by providing a sepsis risk score. Prompt recognition assisting recognition can significantly help shorten the time between recognition and intervention in clinical decision-making processes. Conclusion: This study suggests that using a clinical decision support system can help improve hospital workflows as well as the quality of medical care.

Differences exist between Infectious Diseases Society of America guidance and European Society of Clinical Microbiology and Infectious Diseases guidelines on treating pneumonia caused by carbapenem-resistant Acinetobacter baumannii (CRAB). This study compared the outcomes of colistin-based and high-dose ampicillin/sulbactam-based combination therapies in patients with CRAB nosocomial pneumonia. A retrospective cohort study was conducted at a university-affiliated hospital in South Korea. Patients received either a colistin-based regimen with a loading dose followed by a maintenance dose (June 2021–May 2022) or a high-dose ampicillin/sulbactam-based regimen with sulbactam 9 g/day (October 2022–September 2023). The primary outcome was 28-day all-cause mortality; secondary outcomes included 14-day/28-day clinical success rates and 14-day/28-day kidney injury based on the Risk, Injury, Failure, Loss, End-stage renal disease score. Logistic and Poisson regression analyses were used to compare outcomes between groups. Among 179 patients enrolled in the study, 84 received the colistin-based regimen and 95 received the high-dose ampicillin/sulbactam-based regimen. The ampicillin/sulbactam group showed significantly lower 28-day mortality (20% vs. 61%; adjusted relative risk [aRR] = 0.16, 95% CI 0.08–0.32). Clinical success rates were higher in the ampicillin/sulbactam group at both 14 days (39% vs. 23%; aRR = 2.19, 95% CI 1.10–4.37) and 28 days (55% vs. 32%; aRR = 2.71, 95% CI 1.14–5.20). Additionally, 28-day kidney injury was lower in the ampicillin/sulbactam group (0.63 ± 1.16 vs. 1.06 ± 1.35; aRR = 0.56, 95% CI 0.40–0.79). High-dose ampicillin/sulbactam-based combination therapy demonstrates superior outcomes over colistin-based combination therapy for CRAB nosocomial pneumonia, including lower mortality, higher clinical success rates, and reduced kidney injury.

Background: In hospitals, Code Blue is an emergency that refers to a patient requiring immediate resuscitation. Over 85% of patients with cardiopulmonary arrest exhibit abnormal vital sign trends prior to the event. Continuous monitoring and accurate interpretation of clinical data through artificial intelligence (AI) models can contribute to preventing critical events. Objective: This study aims to evaluate changes in clinical outcomes following the use of VitalCare (Major Adverse Event Score and Mortality Score), which is an AI-based early warning system, and to validate the performance of the algorithm. Methods: A retrospective analysis was conducted by extracting electronic health record data, using a total of 30,785 inpatient cases from general wards and intensive care units. A comparative analysis was performed by setting a 3-month period before and after the system implementation. For clinical evaluation, we measured the incidence rates of Code Blue and adverse events, the proportion of prolonged hospitalization, and the frequency of early interventions. The area under the receiver operating characteristic curve (AUROC) was calculated to assess the performance of the algorithm. Results: This study demonstrated that, following the implementation of VitalCare, there was a 24.97% reduction in major events such as Code Blue (P=.004) and the proportion of prolonged hospitalization in general wards (P<.05), along with a significant increase in the rate of early interventions. The model performance exhibited superior outcomes compared with traditional scoring systems, with a Major Adverse Event Score AUROC of 0.865 (95% CI 0.857‐0.873) and Mortality Score AUROC of 0.937 (95% CI 0.931‐0.944). Conclusions: A well-developed AI-based model that provides high predictive power can contribute to the prevention of major in-hospital events by providing early predictive information to clinicians. Additionally, it plays a crucial role in effectively addressing unmet needs and challenges in terms of human resources and practical procedures.

Background: Acute deterioration of patients in general wards often leads to major adverse events (MAEs), including unplanned intensive care unit transfers, cardiac arrest, or death. Traditional early warning scores (EWSs) have shown limited predictive accuracy, with frequent false positives. We conducted a prospective observational external validation study of an artificial intelligence (AI)-based EWS, the VitalCare - Major Adverse Event Score (VC-MAES), at a tertiary medical center in the Republic of Korea. Methods: Adult patients from general wards, including internal medicine (IM) and obstetrics and gynecology (OBGYN)—the latter were rarely investigated in prior AI-based EWS studies—were included. The VC-MAES predictions were compared with National Early Warning Score (NEWS) and Modified Early Warning Score (MEWS) predictions using the area under the receiver operating characteristic curve (AUROC), area under the precision-recall curve (AUPRC), and logistic regression for baseline EWS values. False-positives per true positive (FPpTP) were assessed based on the power threshold. Results: Of 6,039 encounters, 217 (3.6%) had MAEs (IM: 9.5%, OBGYN: 0.26%). Six hours prior to MAEs, the VC-MAES achieved an AUROC of 0.918 and an AUPRC of 0.352, including the OBGYN subgroup (AUROC, 0.964; AUPRC, 0.388), outperforming the NEWS (0.797 and 0.124) and MEWS (0.722 and 0.079). The FPpTP was reduced by up to 71%. Baseline VC-MAES was strongly associated with MAEs (P<0.001). Conclusions: The VC-MAES significantly outperformed traditional EWSs in predicting adverse events in general ward patients. The robust performance and lower FPpTP suggest that broader adoption of the VC-MAES may improve clinical efficiency and resource allocation in general wards.