Submitted:
16 September 2025
Posted:
18 September 2025
You are already at the latest version
Abstract
Keywords:
1. Introduction
- Assessing SXI++ as a bivariate scorer for triage accuracy-based binary ESI classification using strong preprocessing and feature engineering,
- Scaling up SXI++ scoring to synchronize with triage accuracy for immediate, short-term, and long-term care, and
- Using a decision tree model to determine key indicators (e.g., heart rate, oxy-gen saturation, chest pain) influencing best ESI classification pathways.
2. Materials and Methods
2.1. Dataset Description
- Emergency cases (Levels 1–2): requiring immediate or high-priority care
- Non-emergency cases (Levels 3–5): indicating lower acuity and potentially deferrable care
- Demographics: age, gender, arrival mode (e.g., ambulance, walk-in), and prior healthcare usage
- Triage vital signs: heart rate, respiratory rate, blood pressure, temperature, and oxygen saturation
- Clinical history: presence or absence of chronic conditions (e.g., cancer, cardiovascular disease)
- Chief complaints: binary indicators of reported symptoms (e.g., dizziness, abdominal pain)
| FEATURES | |
| Target | ESI |
| Past medical history | From 2sndarymalig to whtblooddx |
| Demographics | Age |
| Gender | |
| Arrival mode | |
| previousdispo | |
| Triage Vital Signs | triage_vital_hr |
| triage_vital_rr | |
| triage_vital_sbp | |
| triage_vital_temp | |
| triage_vital_o2 | |
| triage_vital_dbp | |
| Chief Complaints | From cc_abdominalcramping to cc_wristpain |
2.2. Interpretation of ESI Distribution
- Emergency (30.1%)—displayed in pink
- No Emergency (69.9%)—displayed in cyan


2.3. Method Use
3. Results
3.1. SXI Distribution
3.2. Confusion Matrix
3.3. Current Decision Tree
3.4. Target Decision Tree
4. Discussions
4.1. Key Findings
4.2. Strengths and Limitations
4.3. Comparison with Similar Research
4.4. Implications, Recommendations, and User Interaction
- Cross-validate SXI++ algorithm on external data, including global and outpatient populations.
- Integrate SXI++ algorithm into electronic medical records (EMR) for real-time monitoring and prediction.
- Carry out prospective trials to measure its effect on patient outcomes, including the reduction of events associated with heart disease.
4.5. Future Investigation
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Abbreviations
| AUC | Area Under the Curve |
| ESI | Emergency Severity Index |
| XGBoost | Extreme Gradient Boosting |
| DNN | Deep Neural Network |
| EMR | Electronic Medical Record |
| ML | Machine Learning |
| R2 | Coefficient of Determination (R-squared) |
| SXI++ | SRIYA EXPERT INDEX PLUS (A deep-learning framework for dynamic weighting of features) |
| LASSO | Least Absolute Shrinkage and Selection Operator |
| PCA | Principal Component Analysis |
| PPV | Positive Predictive Value (Precision) |
| NPV | Negative Predictive Value (Recall) |
| HER | Electronic Health Record |
| ED | Emergency Department |
| SHAP | Shapley Additive Explanations |
| ROC | Receiver Operating Characteristic curve |
| ESI | Emergency Severity Index |
| EDs | Emergency departments |
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| Target Variable | |||
| Emergency Level | Class | Count | % |
| 1-2 | Emergency | 30,102 | 30.1 |
| 3-5 | Non-Emergency | 69,898 | 69.9 |
| Class Division | |||
| Emergency Level | Colour | Count | % |
| 1 | Purple | 560 | 1 |
| 2 | Green | 163,661 | 29.2 |
| 3 | Red | 238,767 | 42.6 |
| 4 | Blue | 124,988 | 22.3 |
| 5 | Orange | 279,683 | 4.99 |
| XGBoost | 95% CI | SXI | 95% CI | SXI++ | 95% CI | |
| Accuracy (%) | 82.9% | [80.59%, 85.21%] | 90.76% | [88.98%, 92.54%] | 99.8% | [99.52%, 99.98%] |
| Precision (%) | 85.5% | [83.32%, 87.68%] | 80.97% | [78.53%, 83.41%] | 99.8% | [99.52%, 99.98%] |
| AUC | 0.779 | NA | 0.967 | NA | 0.999 | NA |
| Sensitivity | 73.7% | [71.06%, 76.34%] | 90.7% | [88.90%, 92.50%] | 99.8% | [99.52%, 99.98%] |
| Specificity | 91.1% | [89.22%, 92.98%] | 92.0% | [90.34%, 93.66%] | 99.8% | [99.52%, 99.98%] |
| XGBoost | 95% CI | SXI | 95% CI | |
| Accuracy (%) | 97.63% | [94.68%, 100%] | 100% | [87.44%, 100%] |
| Precision (%) | 98.11% | [93.59%, 100%] | 100% | [87.44%, 100%] |
| AUC | 0.99 | NA | 1 | NA |
| Sensitivity | 97.37% | [91.85%, 100%] | 100% | [87.44%, 100%] |
| Specificity | 97.86% | [92.96%, 100%] | 100% | [87.44%, 100%] |
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