Weon Jung's research while affiliated with Samsung Medical Center and other places

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Publications (14)


The order and alert process (A) and screenshot (B). Circled numbers in the process chart are matched with those in the screenshot. Hollow stars represent the point when the alert log is recorded. The alert log ID is replaced with the order log ID (solid star) when the order is overridden and confirmed.
Alert override definition. Four representative alert-user interface cases are illustrated. Alert types are grouped into two (adjustable, non-adjustable). (A) Process of alert interaction. (B) Concept of data generation. Processes (1) and (4) reflect intended (but withdrawn) orders.
Medication order selection process. Medication-related order and alert data from January 2018 to April 2020 and August 2019 to December 2020 were used for statistical comparison. Both confirmed and intended (but withdrawn) orders were included in the analysis. The starred (★) alerts were later used to measure alert override rates.
Monthly alert trend. * DDI: drug-drug interaction; **Etc. includes sex, pregnancy, lactation, disease, duplication, and route type alerts. The mentioned alert types were only present in period A; age-type alerts during period B were newly grouped based on alert messages indicating contraindications due to age. In February 2019, the medication clinical decision support system was turned off for two weeks for maintenance purposes. The decrease in dose-type alerts reflects dosage threshold alterations made in the alert firing rule during the study period.
Comparison of knowledgebases. The knowledgebase transition was made from A to B. Coverage is described for each knowledgebase.
Effect of knowledgebase transition of a clinical decision support system on medication order and alert patterns in an emergency department
  • Article
  • Full-text available

December 2023

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24 Reads

Scientific Reports

Weon Jung

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Jaeyong Yu

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Hyunjung Park

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[...]

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A knowledgebase (KB) transition of a clinical decision support (CDS) system occurred at the study site. The transition was made from one commercial database to another, provided by a different vendor. The change was applied to all medications in the institute. The aim of this study was to analyze the effect of KB transition on medication-related orders and alert patterns in an emergency department (ED). Data of patients, medication-related orders and alerts, and physicians in the ED from January 2018 to December 2020 were analyzed in this study. A set of definitions was set to define orders, alerts, and alert overrides. Changes in order and alert patterns before and after the conversion, which took place in May 2019, were assessed. Overall, 101,450 patients visited the ED, and 1325 physicians made 829,474 prescription orders to patients during visit and at discharge. Alert rates (alert count divided by order count) for periods A and B were 12.6% and 14.1%, and override rates (alert override count divided by alert count) were 60.8% and 67.4%, respectively. Of the 296 drugs that were used more than 100 times during each period, 64.5% of the drugs had an increase in alert rate after the transition. Changes in alert rates were tested using chi-squared test and Fisher’s exact test. We found that the CDS system knowledgebase transition was associated with a significant change in alert patterns at the medication level in the ED. Careful consideration is advised when such a transition is performed.

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Overall study flow in the development of PReCAP (Pre-hospital Real-time Cardiac Arrest outcome Prediction model). CPR, cardiopulmonary resuscitation; EMS, emergency medical service; AED, automated external defibrillator; ER, emergency room; ED, emergency department; Dfib, defibrillation.
Study population.
Population included for each minute from 0 to 60 min for developing time-adaptive cohorts. The PReCAP model was built independently for each minute, with an independent time cohort.
Predicted scene return of spontaneous circulation ROSC, survival to discharge from the emergency department (ED), the 30-day survival rate, and the final Cerebral Performance Category (CPC). The prediction rate of non-time adaptive model is shown as a blue line while the prediction rate of PReCAP is shown as an orange line.
Feature importance of ROSC on scene in Pre-Hospital Real Time Precision Model (PReCAP) at 0 min, 5 min and 10 min. noflow_time, Estimated Occurrence time to response time; bystander_time, Bystander CPR time; dr_epi, Prehospital Epinephrine injection; firstrhyth, First Rhythm; typeloc, Location type; pre_air, Prehospital advanced airway; arr_witn, witnessed arrest; by_aed, Bystander AED done; def_amb, Defibrillation in ambulance; frstcpr, first CPR initiator; by_cpr, Bystander CPR done; dev_ab, mechanical CPR device used by EMS/private ambulance; pre_def, prehospital defibrillation; def_frp, defibrilation performed by first responder; def_bylay, defibrillation performed by bystander-lay person.
Machine learning pre-hospital real-time cardiac arrest outcome prediction (PReCAP) using time-adaptive cohort model based on the Pan-Asian Resuscitation Outcome Study

November 2023

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43 Reads

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2 Citations

Scientific Reports

To save time during transport, where resuscitation quality can degrade in a moving ambulance, it would be prudent to continue the resuscitation on scene if there is a high likelihood of ROSC occurring at the scene. We developed the pre-hospital real-time cardiac arrest outcome prediction (PReCAP) model to predict ROSC at the scene using prehospital input variables with time-adaptive cohort. The patient survival at discharge from the emergency department (ED), the 30-day survival rate, and the final Cerebral Performance Category (CPC) were secondary prediction outcomes in this study. The Pan-Asian Resuscitation Outcome Study (PAROS) database, which includes out-of-hospital cardiac arrest (OHCA) patients transferred by emergency medical service in Asia between 2009 and 2018, was utilized for this study. From the variables available in the PAROS database, we selected relevant variables to predict OHCA outcomes. Light gradient-boosting machine (LightGBM) was used to build the PReCAP model. Between 2009 and 2018, 157,654 patients in the PAROS database were enrolled in our study. In terms of prediction of ROSC on scene, the PReCAP had an AUROC score between 0.85 and 0.87. The PReCAP had an AUROC score between 0.91 and 0.93 for predicting survived to discharge from ED, and an AUROC score between 0.80 and 0.86 for predicting the 30-day survival. The PReCAP predicted CPC with an AUROC score ranging from 0.84 to 0.91. The feature importance differed with time in the PReCAP model prediction of ROSC on scene. Using the PAROS database, PReCAP predicted ROSC on scene, survival to discharge from ED, 30-day survival, and CPC for each minute with an AUROC score ranging from 0.8 to 0.93. As this model used a multi-national database, it might be applicable for a variety of environments and populations.




FIG. 1. Model development and validation process. For latent shock patients, vital signs measured within 24 h of latent shock were collected. For non-latent shock patients, vital signs measured within 24 h of the last measurement in the ER were collected. Vital signs were grouped by hour. If there were multiple measurements within an hour, the average was calculated. In cases where patient length of stay or time from visit to latent shock was less than 2 h, the values before visit were left empty.
FIG. 2. Flowchart. DOA, dead on arrival; EMR, electronic medical records; ER, emergency room; KTAS, Korean Triage Acuity Scale; LWBS, left without being seen; MBP, mean blood pressure.
EARLY PREDICTION OF UNEXPECTED LATENT SHOCK IN THE EMERGENCY DEPARTMENT USING VITAL SIGNS

July 2023

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25 Reads

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1 Citation

Shock (Augusta, Ga.)

Objective/introduction: Sequential vital-sign information and trends in vital signs are useful for predicting changes in patient state. This study aims to predict latent shock by observing sequential changes in patient vital signs. Methods: The dataset for this retrospective study contained a total of 93,194 emergency department (ED) visits from January 1, 2016, and December 31, 2020, and Medical Information Mart for Intensive Care (MIMIC)-IV-ED data. We further divided the data into training and validation datasets by random sampling without replacement at a 7:3 ratio. We carried out external validation with MIMIC-IV-ED. Our prediction model included logistic regression (LR), random forest (RF) classifier, a multi-layer perceptron (MLP), and a recurrent neural network (RNN). To analyze the model performance, we used area under the receiver operating characteristic curve (AUROC). Results: Data of 89,250 visits of patients who met pre-specified criteria were used to develop a latent-shock prediction model. Data of 142,250 patient visits from MIMIC-IV-ED satisfying the same inclusion criteria were used for external validation of the prediction model. The AUROC values of prediction for latent shock were 0.822, 0.841, 0.852, and 0.830 with RNN, MLP, RF, and LR methods, respectively, at 3 h before latent shock. This is higher than the shock index or adjusted shock index. Conclusion: We developed a latent shock prediction model based on 24 hours of vital-sign sequence that changed with time and predicted the results by individual.


Probabilities of renal adaptation according to the score. Probabilities of fair renal adaptation according to the scores (A) and observed and predicted probabilities of fair renal adaptation according to the score groups. A score of ≥12 ensures fair renal adaptation with a probability of >95%. (B). Probabilities of good renal adaptation according to the scores (C) and observed and predicted probabilities of good renal adaptation according to score groups (D).
Receiver operating characteristic (ROC) curves and area under the precision-recall curve (AUPRC) for each outcome. The area under the ROC was 0.846 (95% confidence interval [CI], 0.762–0.930) and 0.626 (0.541–0.712), while the AUPRC was 0.965 (95% CI, 0.944–0.978) and 0.709 (0.647–0.788) for fair (A,B) and good (C,D) renal adaptation, respectively.
Web-based interactive clinical decision support system: Renal Adaptation Prediction Tool prior to Operation (RAPTO). RAPTO consists of an input (A) and an output (B) part. As a result of the input part, the output part provides the sum of scores, along with the probability of fair or good renal adaptation corresponding to that score. The fair and good renal adaptation models included pre-donation eGFR, age, sex, BMI, and normalized GFR (on DTPA) of the remaining kidney, CT volume percentage of the remaining kidney, and CT volume of the remaining kidney/body weight. Additionally, the fair renal adaptation model included cystatin C eGFR, while the good renal adaptation model included pre-donation creatinine clearance and serum creatinine. The RAPTO is available online at https://jaeyongyu.shinyapps.io/rapto/. BMI, body mass index; CT, computed tomography; DTPA, diethylenetriamine pentaacetate; and eGFR, estimated glomerular filtration rate.
Pre-donation baseline characteristics according to good renal adaptation after living kidney donation.
Continued)
Prediction tool for renal adaptation after living kidney donation using interpretable machine learning

July 2023

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24 Reads

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1 Citation

Frontiers in Medicine

Frontiers in Medicine

Introduction Post-donation renal outcomes are a crucial issue for living kidney donors considering young donors’ high life expectancy and elderly donors’ comorbidities that affect kidney function. We developed a prediction model for renal adaptation after living kidney donation using interpretable machine learning. Methods The study included 823 living kidney donors who underwent nephrectomy in 2009–2020. AutoScore, a machine learning-based score generator, was used to develop a prediction model. Fair and good renal adaptation were defined as post-donation estimated glomerular filtration rate (eGFR) of ≥ 60 mL/min/1.73 m ² and ≥ 65% of the pre-donation values, respectively. Results The mean age was 45.2 years; 51.6% were female. The model included pre-donation demographic and laboratory variables, GFR measured by diethylenetriamine pentaacetate scan, and computed tomography kidney volume/body weight of both kidneys and the remaining kidney. The areas under the receiver operating characteristic curve were 0.846 (95% confidence interval, 0.762–0.930) and 0.626 (0.541–0.712), while the areas under the precision-recall curve were 0.965 (0.944–0.978) and 0.709 (0.647–0.788) for fair and good renal adaptation, respectively. An interactive clinical decision support system was developed. ¹ Conclusion The prediction tool for post-donation renal adaptation showed good predictive capability and may help clinical decisions through an easy-to-use web-based application.


ED LOS and patient visits each month from February 1, 2016, to June 31, 2019. LOS is presented as a linear graph and patient visits as a bar. Proportion of KTAS level is indicated by bar color
Hourly distribution of patients based on their emergency department length of stay. After policy introduced, event on 23 hour was shown in orange color
Proportion of patients who stayed for more than 24 hours from February 1, 2016, to June 31, 2019. The red dotted line represents 5% of total visit patients, which is the target proportion of the policy
Survey response summary of ED medical professionals. Each color represents answer to each survey question. (Light blue: Very improved, Yellow: Improved, Gray: Not that changed, Orange: Worsened, Deep blue: Considerable worsened) Detailed data are presented in Supplementary table 4
Impact of the 24-hour time target policy for emergency departments in South Korea: a mixed method study in a single medical center

December 2022

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58 Reads

BMC Health Services Research

Background In South Korea, after the spread of the Middle East Respiratory Syndrome epidemic was aggravated by long stays in crowded emergency departments (EDs), a 24-hour target policy for EDs was introduced to prevent crowding and reduce patients' length of stay (LOS). The policy requires at least 95% of all patients to be admitted, discharged or transferred from an ED within 24 hours of arrival. This study analyzes the effects of the 24-hour target policy on ED LOS and compliance rates and describes the consequences of the policy. Methods A mixed-methods approach was applied to a retrospective observational study of ED visits combined with a survey of medical professionals. The primary measure was ED LOS, and the secondary measure was policy compliance rate which refers to the proportion of patient visits with a LOS shorter than 24 hours. Patient flow, quality of care, patient safety, staff workload, and staff satisfaction were also investigated through surveys. Mann–Whitney U and χ2 tests were used to compare variables before and after the introduction of the policy. Results The median ED LOS increased from 3.9 hours (interquartile range [IQR] = 2.1–7.6) to 4.5 hours (IQR = 2.5–8.5) after the policy was introduced. This was likely influenced by the average monthly number of patients, which greatly increased from 4819 (SD = 340) to 5870 (SD = 462) during the same period. The proportion of patients with ED LOS greater than 24 hours remained below5% only after 6 months of policy implementation, but the number of patients whose disposition was decided at 23 hours increased by 4.84 times. Survey results suggested that patient flow and quality of care improved slightly, while the workload of medical staff worsened. Conclusions After implementing the 24-hour target policy, the proportion of patients whose ED LOS exceeded 24 hours decreased, even though the median ED LOS increased. However, the unintended consequences of the policy were observed such as increased medical professional workload and abrupt expulsion of patients before 24 hours.



Receiver operating characteristics (ROC) curve for internal validation outcome on the time-validation set.
Ordering a head CT binary decision results on the simulation cases.
Process of simulation scenario.
Decision effect of a deep-learning model to assist a head computed tomography order for pediatric traumatic brain injury

July 2022

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29 Reads

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5 Citations

Scientific Reports

The study aims to measure the effectiveness of an AI-based traumatic intracranial hemorrhage prediction model in the decisions of emergency physicians regarding ordering head computed tomography (CT) scans. We developed a deep-learning model for predicting traumatic intracranial hemorrhages (DEEPTICH) using a national trauma registry with 1.8 million cases. For simulation, 24 cases were selected from previous emergency department cases. For each case, physicians made decisions on ordering a head CT twice: initially without the DEEPTICH assistance, and subsequently with the DEEPTICH assistance. Of the 528 responses from 22 participants, 201 initial decisions were different from the DEEPTICH recommendations. Of these 201 initial decisions, 94 were changed after DEEPTICH assistance (46.8%). For the cases in which CT was initially not ordered, 71.4% of the decisions were changed (p < 0.001), and for the cases in which CT was initially ordered, 37.2% (p < 0.001) of the decisions were changed after DEEPTICH assistance. When using DEEPTICH, 46 (11.6%) unnecessary CTs were avoided (p < 0.001) and 10 (11.4%) traumatic intracranial hemorrhages (ICHs) that would have been otherwise missed were found (p = 0.039). We found that emergency physicians were likely to accept AI based on how they perceived its safety.


Effect of knowledgebase transition of a clinical decision support system on medication order and alert patterns in an emergency department

July 2022

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6 Reads

Objective A knowledgebase (KB) transition of a clinical decision support (CDS) system occurred at the study site. The transition was made from one commercial database to another, provided by a different vendor. The change was applied to all medications in the institute. The aim of this study was to analyze the effect of KB transition on medication-related orders and alert patterns in an emergency department (ED). Methods Data of patients, medication-related orders and alerts, and physicians in the ED from January 2018 to December 2020 were analyzed in this study. A set of definitions was set to define orders, alerts, and alert overrides. Changes in order and alert patterns before and after the conversion, which took place in May 2019, were assessed. Results Overall, 101,450 patients visited the ED, and 1,325 physicians made 829,474 prescription orders. Alert rates (alert count divided by order count) for periods A and B were 12.6% and 14.1%, and override rates (alert override count divided by alert count) were 60.8% and 67.4%, respectively. Of the 296 drugs that were used more than 100 times during each period, 64.5% of the drugs had an increase in alert rate after the transition. Changes in alert rates were tested using chi-squared test and Fisher’s exact test. Conclusion We found that the CDS KB transition was associated with a significant change in alert patterns at the medication level in the ED. Careful consideration is advised when such a transition is performed.


Citations (5)


... When it comes to donors, machine learning research is very scarce. To our knowledge, there is only one recent work using machine learning, carried out by a Korean study group, to predict renal adaptation of living kidney donors [12]. ...

Reference:

First experiences with machine learning predictions of accelerated declining eGFR slope of living kidney donors 3 years after donation
Prediction tool for renal adaptation after living kidney donation using interpretable machine learning
Frontiers in Medicine

Frontiers in Medicine

... This phenomenon has already been reported previously, showing that this problem can cause physicians to start ignoring these alerts after an excess of generated alerts, increasing the risk of alerts with greater clinical importance going unnoticed. 39 Some studies included in this review evaluated the effect of adjustments in the rules of the clinical decision support system to reduce the number of alerts generated. After these adjustments, only alerts of greater clinical importance were generated; with this, the number of alerts decreased significantly, although the acceptance of these alerts did not increase significantly, and physicians continued to override most of these alerts. ...

Appropriateness of Alerts and Physicians’ Responses with a Medication-related Clinical Decision Support System (Preprint)

JMIR Medical Informatics

... Since the WIC 4 developed in this study is mainly used to predict severe brain injury, it is a typical binary classi cation task since it is divided the head injury level in 50 accidents into two categories severe and non-severe. The Area under the receiver operating characteristic (AUROC, abbreviated as AUC) is a common performance evaluation metric for binary classi cation models 19,35,45 , with values ranging from 0.5 to 1. The closer the value is to 1, the better the model prediction performance. ...

Decision effect of a deep-learning model to assist a head computed tomography order for pediatric traumatic brain injury

Scientific Reports

... 4 -6 Notably, the proportion of patients with a fever or respiratory symptoms (FRS) in the ED decreased, while those waiting for assistance increased, compared to pre-pandemic times. 4 Cancer patients often visit the ED due to symptoms from the disease and side effects of cancer treatments, 7 where they utilize numerous ED resources. 8 A recent study from South Korea found that visits to the ED for acute cancer treatments rose annually from 2017 to 2019, accounting for 5.5% of all ED visits. ...

Effect of fever or respiratory symptoms on leaving without being seen during the COVID-19 pandemic in South Korea

Clinical and Experimental Emergency Medicine

... Alert overrides occur when physicians do not change orders as suggested by the alert. Our previous study defined an alert override as no change in order when an alert occurred on the log data [22]. In this study, however, alert override means no change in order when an alert occurred or a re-order of the same prescription later. ...

Temporal Change in Alert Override Rate with a Minimally Interruptive Clinical Decision Support on a Next-Generation Electronic Medical Record

Medicina