Heart disease remains one of the leading causes of mortality globally, affecting millions of lives each year. By leveraging data analytics and predictive modeling, we aim to identify patients at a higher risk of developing heart disease based on their medical attributes. This project uses a heart disease dataset to create a machine learning model that predicts the likelihood of heart disease in the near future, offering a potentially valuable tool for early intervention.
This dataset originates from the University of California Irvine's Machine Learning Repository (here) and is also accessible through OpenML. It includes various patient attributes that can signal heart health, providing an ideal foundation for predicting cardiovascular disease risk. Download the dataset
The dataset contains key medical metrics and health indicators associated with cardiovascular well-being. Below are the main features:
Age: Patient's age in years.
Sex: Patient's gender, coded as:
1: Male
0: Female
Chest Pain Type: Types of chest pain experienced, reflecting heart stress levels:
1: Typical angina (chest pain due to restricted blood flow)
2: Atypical angina (not directly heart-related)
3: Non-anginal pain (unrelated to the heart)
4: Asymptomatic (no chest pain)
Resting Blood Pressure (BP): Blood pressure when the heart is at rest, measured in mmHg.
Cholesterol: Serum cholesterol levels in mg/dl, often associated with cardiovascular risk.
Indicates whether fasting blood sugar is above 120 mg/dl.
1: True
0: False
Resting Electrocardiographic (EKG) Results: Reflects the heart’s electrical activity:
0: Normal
1: ST-T wave abnormality (e.g., T wave inversions or ST elevation)
2: Possible left ventricular hypertrophy
Maximum Heart Rate Achieved (Max HR): Maximum heart rate recorded during a stress test.
Exercise-Induced Angina: Presence of angina during exercise:
1: Yes
0: No
ST Depression Induced by Exercise (ST_depressi): Reflects ST segment depression during exercise, indicating ischemia.
Slope of Peak Exercise ST Segment (Slope_of_ST): Assesses heart stress through the ST segment’s slope:
1: Upsloping
2: Flat
3: Downsloping
Number of Major Vessels Colored by Fluoroscopy: Visible major blood vessels under fluoroscopy, suggesting artery blockage.
Thallium Stress Test Result: Observes blood flow into the heart:
3: Normal
6: Fixed defect (no blood flow in a heart region)
7: Reversible defect (restricted blood flow during exercise)
Heart Disease: The target variable indicating heart disease presence or absence.
This project applies machine learning techniques & uses Python as the tool to analyze these medical features and predict heart disease risk, providing insights that may aid in timely diagnosis and intervention.
Below are some initial insights from the descriptive analysis of key numerical features:
🔍 Age: Patients span from 29 to 77 years, with an average age of 54, highlighting a broad demographic distribution.
💓 Blood Pressure: The average resting blood pressure is 131 mm Hg, with a peak of 200 mm Hg, underlining varying cardiovascular stress levels.
🧪 Cholesterol: Cholesterol levels vary widely, with some reaching up to 564 mg/dl, pointing to elevated cardiovascular risks in certain cases.
🏃 Max Heart Rate: Peaks at 202 bpm, reflecting the diverse physical and cardiovascular health conditions across the dataset.
📉 ST Depression: A maximum of 6.2 mm suggests significant ischemic changes, indicative of critical heart conditions in some individuals.
🩺 Vessel Visibility: Fluoroscopy reveals up to 3 visible blood vessels, signaling coronary artery disease in several patients.
This heatmap serves as a great visual aid to identify potential interactions between variables, which can guide feature selection for the predictive modeling.
📉 Age vs. Max Heart Rate:
A moderate negative correlation (-0.4) reveals that maximum heart rate tends to decline with age, consistent with medical insights on cardiovascular function over time.
📊 ST Depression vs. Max Heart Rate:
A slight negative correlation (-0.35) suggests that higher ST depression values, often linked to ischemia, might coincide with lower maximum heart rates.
🔗 Age vs. Number of Vessels (Fluoroscopy):
A moderate positive correlation (0.36) indicates that older patients are more likely to have visible vessels under fluoroscopy, hinting at an increased risk of cardiovascular issues with age.
📉 Age vs. Max Heart Rate:
A moderate negative correlation (-0.4) reveals that maximum heart rate tends to decline with age, consistent with medical insights on cardiovascular function over time.
📊 ST Depression vs. Max Heart Rate:
A slight negative correlation (-0.35) suggests that higher ST depression values, often linked to ischemia, might coincide with lower maximum heart rates.
🔗 Age vs. Number of Vessels (Fluoroscopy):
A moderate positive correlation (0.36) indicates that older patients are more likely to have visible vessels under fluoroscopy, hinting at an increased risk of cardiovascular issues with age.
📈 Increasing Risk with Age:
Heart disease presence rises significantly with age, particularly among individuals 50 and older. Structural changes in blood vessels and the heart contribute to this trend, aligning with established medical insights.
👵 High Prevalence in Older Groups:
In those 60+, cumulative exposure to factors like high cholesterol and hypertension leads to a visibly higher prevalence of heart disease.
🧒 Lower Risk in Younger Groups:
For individuals under 40, heart disease cases are minimal, reflecting fewer accumulated risks or stronger cardiovascular health in younger ages.
🔍 Unique Outliers:
Instances of heart disease in younger individuals may highlight genetic predispositions, congenital conditions, or significant lifestyle influences.
💡 Validation of Research:
These trends align with findings from the American Heart Association (AHA), emphasizing how aging, blood vessel elasticity loss, and cholesterol buildup heighten cardiovascular risks.
Fluoroscopy, an advanced X-ray technique, helps visualize and assess coronary artery disease (CAD) by counting blockages in up to three blood vessels. CAD, caused by plaque buildup, narrows arteries and can lead to heart attacks or angina, making this imaging vital for effective diagnosis and treatment planning.
🌟 Age and Vessel Blockage
The chart highlights a clear trend: as age increases, more blood vessels tend to be affected by blockages. This aligns with medical insights that the risk of coronary artery disease (CAD) grows with age.
🔍 Severity of CAD
Higher "Number of Vessels Fluoro" values signal more severe CAD. Blocked vessels mean reduced blood flow to the heart, significantly raising the risk of complications.
📊 Predictive Value
This feature is a powerful predictor of heart disease. Patients with more blocked vessels are more likely to be diagnosed, emphasizing its importance in the model.
🩺 Treatment Decisions
This insight directly supports clinical decisions. Patients with multiple blockages may require urgent interventions like angioplasty or bypass surgery to improve outcomes.
These charts could serve as a strong foundation for overall analysis, particularly if we are looking to identify age-based risk factors or health patterns.
📈 Blood Pressure vs. Age:
Blood pressure tends to rise with age, with some noticeable fluctuations around 60-70 years. This is consistent with common health trends, where older individuals generally experience higher blood pressure levels.
🔄 Cholesterol Level vs. Age:
Cholesterol levels show some variability but don’t follow a clear upward or downward trend with age. This suggests that age alone might not play a major role in influencing cholesterol levels in this sample.
❤️ Maximum Heart Rate vs. Age:
As expected, the maximum heart rate declines with age. This downward trend aligns with physiological norms, where the heart’s maximum capacity decreases as individuals age.
⚠️ ST Depression vs. Age:
ST depression values fluctuate across various age groups, with noticeable spikes in the 30-50 age range. This variability may indicate differing heart stress responses among these groups, which could be worth further exploration in relation to heart disease risk.
Introduction: 🚀
Random Forest is a powerhouse in machine learning, widely used for both classification and regression tasks. Built on ensemble learning, this algorithm combines multiple models to deliver more accurate, stable predictions. In the case of Random Forest, several decision trees are created and then aggregated for a final decision. This method is perfect for tackling complex datasets, as it reduces overfitting and boosts the model’s robustness. In this case, we’re applying Random Forest to predict heart disease risk, ensuring we maximize both accuracy and interpretability at every step.
Random Forest Basics: 🌳
Ensemble Learning: 🤝
Random Forest thrives on ensemble learning, where multiple decision trees collaborate to improve prediction accuracy. Think of it as a team of experts making decisions together!
Decision Trees: 🌲
Each decision tree in the Random Forest is trained on a random subset of data and features. This randomness helps prevent overfitting and ensures the trees don’t become too similar to one another, making the overall model more reliable.
Voting: 🗳️
For classification tasks like predicting heart disease, each decision tree makes a prediction, and the Random Forest takes the "majority vote" to make the final call. This voting mechanism helps avoid individual errors and increases accuracy.
Feature Importance: 📊
One of the key strengths of Random Forest is its ability to assess which features (such as age, cholesterol, etc.) are the most influential in predicting outcomes. This helps to better understand the factors driving the model’s predictions.
Steps for Using Random Forest to Predict Heart Disease: 💡
1. Data Preparation 📊
Load the Data: 📥
Begin by importing the dataset using libraries like pandas, bringing in the data which needs to analyze.
Handle Missing Values: 🚫❓
Ensure no missing data is left unaddressed. We can either impute missing values or remove incomplete entries—both essential for a clean dataset.
Convert Categorical Features: 🔄
For categorical variables (e.g., gender, pain level), convert them into numerical format using encoding techniques like one-hot or ordinal encoding. This step makes sure the model can properly interpret the data.
Normalize/Scale Data: 📏
While Random Forest doesn’t require feature scaling, normalizing data like blood pressure or cholesterol can sometimes give the model a performance boost—helping to ensure all features are on a comparable scale.
Feature Selection: 🧠
Random Forest is good at handling irrelevant features, but by selecting only the most important ones, we can improve both model performance and reduce computation time.
2. Split the Data 🔄
Train-Test Split: 💻
Divide your data into training and testing sets, commonly an 80/20 split. This gives us a solid foundation to train the model and then assess its performance on unseen data.
3. Train the Random Forest Model 🌳
Import and Initialize: ⚙️
Import the Random Forest classifier from scikit-learn, and configure it with parameters like n_estimators (number of trees) and max_depth (maximum tree depth).
Fit the Model: 🏋️♂️
Train the model using the prepared training data. It will learn patterns from the data that help predict heart disease risk.
4. Evaluate the Model 🔍
Performance Metrics: 📏
Assess the model's performance using accuracy, precision, recall, F1-score, and AUC-ROC. Cross-validation helps provide more reliable performance metrics, ensuring the model generalizes well.
5. Interpret Results 🧩eature Importance: 💡
Random Forest provides valuable insights into which features (e.g., age, cholesterol levels) have the greatest impact on predicting heart disease. This helps to understand what drives the model’s decision-making process.
Understanding Data Types in the Dataset: 🧮
Ordinal Data: 📊
This is categorical data with a meaningful order, such as pain levels (mild, moderate, severe). Understanding this helps us encode the data appropriately.
Nominal Data: 🏷️
Categorical data without a meaningful order, such as color or gender. Correct encoding ensures the model properly handles these variables.
Model Training Process:
The journey of training the Random Forest model to predict heart disease started with careful data preparation and systematic training:
1. Data Preprocessing 🧹
To ensure that the dataset was ready for the model, several important steps were taken:
Target Variable Encoding: 💡
The target variable, Heart_Disease, was transformed into a numeric format for easier processing: 'Presence' was mapped to 1, and 'Absence' to 0.
Ordinal Encoding: 🔢
For features with a natural order (like Chest_pain_type, EKG_results, Slope_of_ST, and Thallium), ordinal encoding was applied to give the model a clear understanding of the relationships between values.
Data Splitting: 🔀
The data was split into an 80/20 split—80% for training and 20% for testing. This allows us to evaluate the model’s ability to generalize to unseen data.
2. Model Training 🚂
The heart of the process—training the model:
Random Forest Classifier: 🌳
A RandomForestClassifier was trained with 100 decision trees (n_estimators=100). This ensemble method helps the model make more accurate predictions by combining the power of multiple decision trees.
Making Predictions: 🔮
After training the model, predictions were made using the test data to assess its performance on real-world unseen data.
3. Evaluation Results 📊
Now, let's evaluate how well the model performed:
Accuracy: 0.7962962962962963
Classification Report:
precision recall f1-score support
(Absence) 0 0.81 0.88 0.84 33
(Presence) 1 0.78 0.67 0.72 21
accuracy 0.80 54
macro avg 0.79 0.77 0.78 54
weighted avg 0.79 0.80 0.79 54
Confusion Matrix:
[[29 4]
[ 7 14]]
Accuracy: ✅
The model achieved an accuracy of 79.6% on the test data. This means that 80% of the predictions made were correct, showing the model is reasonably reliable.
Classification Report: 📈
Precision is strong for Class 0 (no heart disease) at 81%, meaning most of the time when the model predicts no heart disease, it's correct. For Class 1 (heart disease), it’s a little lower at 78%.
Recall for Class 0 is excellent at 88%, showing the model is good at identifying cases of no heart disease. However, for Class 1, the recall is only 67%, meaning the model misses a fair number of heart disease cases.
F1-Score: The harmonic mean of precision and recall gives an overall measure of performance: 0.84 for no heart disease and 0.72 for heart disease.
4. Confusion Matrix: 🧩
This matrix breaks down the predictions made by the model:
True Negatives (29): Correctly predicted no heart disease.
False Positives (4): Incorrectly predicted heart disease when there was none.
False Negatives (7): Missed detecting heart disease when it was actually present.
True Positives (14): Correctly identified heart disease cases.
5. Conclusion: 🎯
While the model does well with detecting cases of no heart disease, it’s less sensitive when identifying heart disease cases, as evidenced by the lower recall for Class 1. This is something to work on, but overall, the Random Forest model offers a solid prediction framework for heart disease risk.
Why Use Grid Search for the Best Configuration? 🔧
While the initial performance of the Random Forest model is promising, there’s always room for improvement. The current model was trained with default parameters, but hyperparameter tuning can significantly enhance its performance. This is where Grid Search comes into play!
Grid Search is a process that systematically tests a range of hyperparameter values to identify the best possible combination for optimal model performance. Here’s why we use it:
Improving Accuracy: 📊
By finding the best hyperparameters, Grid Search can boost the overall accuracy of the model, ensuring it provides more reliable predictions.
Enhancing Recall for Heart Disease: ❤️
One of the key goals of this tuning process is to improve the recall for class 1 (heart disease), making the model more sensitive to detecting actual cases of heart disease.
In summary, Grid Search helps us discover the ideal configuration, ensuring the model is as effective as possible in predicting heart disease risk.
Best Model Evaluation Results (After Grid Search): 🚀
Accuracy: 0.8518518518518519
Classification Report:
precision recall f1-score support
0 0.84 0.94 0.89 33
1 0.88 0.71 0.79 21
accuracy 0.85 54
macro avg 0.86 0.83 0.84 54
weighted avg 0.86 0.85 0.85 54
Confusion Matrix:
[[31 2]
[ 6 15]]
After tuning the Random Forest model with Grid Search, we observed significant improvements in performance. Here are the new evaluation metrics:
Accuracy: ✅
The accuracy has jumped from 79.6% to 85.2%, demonstrating the positive impact of fine-tuning the model.
Key Performance Insights:
Class 0 (No Heart Disease):
Recall: 94% 🎯
This means the model is now correctly identifying a higher percentage of individuals who don’t have heart disease. The reduction in False Positives helps avoid incorrectly classifying healthy individuals as having heart disease.
Class 1 (Heart Disease):
Precision: 88% 💎
The model is now more accurate when predicting the presence of heart disease, which reduces the number of False Positives for heart disease cases.
Recall: Improved from 67% to 71% 📈
The model is now better at detecting actual heart disease cases, although there’s still some room to improve its sensitivity for this class.
Performance Summary: 📊
The Grid Search process has greatly enhanced the model’s accuracy, precision, and recall. The model is now more balanced, accurately identifying both heart disease and non-heart disease cases. This fine-tuning shows the importance of hyperparameter optimization in making machine learning models not only more accurate but also more reliable in real-world applications.
While the Random Forest model has shown impressive improvements, there’s still room to boost its recall for Class 1 (Heart Disease). Recall is especially important when it comes to identifying patients with heart disease, as it directly impacts how many true cases the model can catch. To tackle this challenge, we can apply SMOTE (Synthetic Minority Over-sampling Technique), a powerful method used to balance imbalanced datasets. 🏥
Why SMOTE Helps:
SMOTE generates synthetic samples for the minority class (Heart Disease) by creating new data points between existing ones. This allows the model to learn better from the underrepresented class, ultimately improving its sensitivity to heart disease cases. Given that Class 1 often has a lower recall, SMOTE can help by boosting the number of heart disease examples in the dataset. This should lead to better detection of heart disease and reduce the chances of False Negatives.
Accuracy: 0.8518518518518519
Classification Report:
precision recall f1-score support
0 0.86 0.91 0.88 33
1 0.84 0.76 0.80 21
accuracy 0.85 54
macro avg 0.85 0.84 0.84 54
weighted avg 0.85 0.85 0.85 54
Confusion Matrix:
[[30 3]
[ 5 16]]
Accuracy: ✅
Before SMOTE: 0.8519
After SMOTE: 0.8519
Interpretation: While accuracy remained unchanged, the important changes are seen in recall and precision.
Class 0 (No Heart Disease):
Precision: Increased from 0.84 to 0.86 💡
The model now better identifies cases without heart disease, reducing False Positives.
Recall: Dropped slightly from 0.94 to 0.91 ⚖️
A small decrease in recall indicates a slight trade-off in terms of not correctly identifying all true negative cases.
F1-Score: Marginal drop from 0.89 to 0.88 🏅
Overall, the balance between precision and recall is still strong but slightly adjusted.
Class 1 (Heart Disease):
Precision: Decreased from 0.88 to 0.84 🔻
There is a slight increase in False Positives, but this is an acceptable trade-off given the improvements in recall.
Recall: Improved significantly from 0.71 to 0.76 🎉
SMOTE greatly enhanced the model's ability to identify true heart disease cases, which is the critical improvement.
F1-Score: Increased from 0.79 to 0.80 ⬆️
A stronger balance between precision and recall for Class 1, making the model better overall.
3. Confusion Matrix Before and After SMOTE: 🧩
Before SMOTE:
Actual No Disease (0) True Negatives = 31, False Positives = 2
Actual Disease (1) False Negatives = 6, True Positives = 15
After SMOTE:
Actual No Disease (0) True Negatives = 30, False Positives = 3
Actual Disease (1) False Negatives = 5, True Positives = 16
Class 0:
SMOTE caused 1 additional False Positive. This means the model is slightly more likely to mistakenly predict someone as having heart disease when they don’t.
Class 1:
SMOTE reduced False Negatives by 1, helping the model catch 1 more true heart disease case.
Improved Recall for Heart Disease:
SMOTE raised recall for Class 1 from 71% to 76%, meaning the model can now catch more actual heart disease cases. This is crucial for medical applications where missing a diagnosis could be life-threatening.
Slight Trade-off in Precision:
While precision for both classes decreased slightly, this trade-off is acceptable. It’s better to mistakenly flag someone as having heart disease (False Positive) than to miss someone who needs treatment (False Negative).
Better Handling of Imbalanced Data:
Despite accuracy remaining unchanged, the F1-score for Class 1 improved, showing that the model is now better equipped to handle the class imbalance issue that was present before SMOTE.
The Importance of SMOTE in Medical Applications:
In medical contexts, particularly heart disease detection, recall is paramount. Missing a heart disease case could have severe consequences. By increasing recall from 71% to 76%, the SMOTE model ensures fewer patients with heart disease are overlooked, improving the model’s reliability and safety for real-world applications.
While there’s a slight increase in False Positives, this is a reasonable trade-off to catch more positive cases. SMOTE makes the model better at detecting heart disease, ensuring it’s safer and more accurate in practical use.
With SMOTE, this model is now even more suited for applications where identifying true heart disease cases is critical. By reducing the chances of False Negatives, SMOTE makes the model more effective and reliable—critical in life-and-death medical situations.
The Feature Importance Plot chart shows the relative importance of each feature in predicting the presence or absence of heart disease.
🧪 Thallium Test Results and 💉 Number of Vessels Fluoroscopy emerged as the most crucial indicators, emphasizing the importance of advanced medical tests in assessing heart health.
Significant Contributing Factors:
💔 Chest Pain Type, 💪 Maximum Heart Rate, and 📉 ST Depression played a substantial role in predicting heart disease risk, highlighting the significance of patient symptoms and physiological responses.
Moderate Impact:
⏳ Age, 🩸 Cholesterol Levels, and 📈 Blood Pressure were identified as moderately important factors, reinforcing their established connection to heart health.
Visualizes the performance of your heart disease prediction model.
True Negatives (TN) - 30 ✅
The model correctly identified 30 cases where heart disease was absent, showcasing its ability to accurately predict healthy individuals. Great job in avoiding false alarms!
False Positives (FP) - 3 ❌
There were 3 cases where the model incorrectly predicted heart disease, flagging healthy individuals as at risk. A small mistake, but important to improve upon to avoid unnecessary concern for patients.
False Negatives (FN) - 5 ⚠️
5 instances where the model missed predicting heart disease, failing to identify those who actually had the condition. This is the area for improvement, as catching these cases is crucial in medical settings.
True Positives (TP) - 16 ❤️
The model accurately identified 16 patients with heart disease, ensuring that individuals in need of care are correctly flagged. This is the win! It highlights the model’s ability to detect true positive cases, which is the ultimate goal.
The model does a good job identifying healthy individuals (30 TNs), but there's room for improvement in detecting heart disease cases (5 FNs). The goal is to reduce false negatives and increase the sensitivity to ensure that more heart disease cases are identified. False positives (3) are relatively low, but should still be minimized to avoid unnecessary treatment or testing.
With 16 true positives, the model is accurately predicting heart disease for many, but with some tweaks, especially using SMOTE or other techniques, it could do even better in catching the ones it missed.
The ROC curve and AUC score provide valuable insights into model's classification performance, especially its ability to distinguish between positive and negative classes.
The ROC Curve is a powerful tool for evaluating how well a model classifies between two classes. It does this by plotting two key metrics:
True Positive Rate (TPR) – Sensitivity/Recall 📊:
This is the proportion of actual positives correctly identified by the model (think of it as the hit rate for detecting heart disease).
✅ High TPR = Better at catching heart disease cases.
False Positive Rate (FPR) – False Alarms 🚨:
This is the proportion of actual negatives that were incorrectly flagged as positives (i.e., when the model mistakenly says someone has heart disease).
❌ Low FPR = Fewer false alarms.
An ideal ROC curve should hug the top-left corner, indicating high sensitivity and low false alarms – we want the model to catch as many true positives as possible without over-predicting false positives.
AUC – Area Under the Curve: 🏆
The AUC (Area Under the Curve) gives us a single number to summarize the model’s overall performance:
AUC = 1.0: Perfect classification 🎯.
AUC = 0.5: No better than random guessing 🤷♂️.
AUC > 0.8: Good discriminatory power 💪, meaning the model does a great job distinguishing between heart disease and no heart disease.
Here's an engaging version of your ROC Curve and AUC explanation with added emojis to make it more exciting for a hiring manager:
For our heart disease prediction model, the AUC = 0.89 – that's a fantastic score! 🎉
This high AUC indicates that the model is excellent at correctly classifying heart disease cases with great accuracy, while maintaining low false positives.
The 0.89 AUC means that our model can reliably identify patients at risk of heart disease without causing too many false alarms, which is critical for healthcare applications.
This model is not just good, it's very accurate enough at predicting heart disease. With an AUC of 0.89, it demonstrates strong discriminatory power – meaning it can be reliable for real-world use in identifying patients at risk, making it a valuable tool for healthcare professionals!
The precision-recall curve evaluates the trade-off between precision (how many positive predictions were correct) and recall (how many actual positives were captured) across different thresholds.
High Precision, Low Recall 🎯:
At low recall, the model achieves near-perfect precision, meaning it's good at predicting heart disease but misses some cases (low recall).
Precision Drops with Higher Recall ⬇️:
As recall increases (catching more positives), precision drops slightly, indicating a trade-off between capturing more cases and introducing more false positives.
Balanced Performance:
The curve shows the model keeps high precision even when recall increases, but it struggles a bit with capturing all positives.
Trade-off:
As the model tries to catch more heart disease cases, precision declines slightly, meaning some false positives are introduced.
The model accurately predicts heart disease (high precision) and identifies most true cases (high recall) but could benefit from threshold fine-tuning to balance the trade-off.
Fine-tuning the threshold could help decide whether we prioritize minimizing false positives or catching all possible heart disease cases. 🎛️
The calibration curve compares the predicted probabilities from your Random Forest model to the actual probabilities of the positive class (i.e., how well the model's predicted probabilities align with reality).
Underestimation at Low Probabilities ❌:
For predicted probabilities around 0.2 to 0.4, the model tends to underestimate the true probability (below the diagonal line).
Better Alignment at Higher Probabilities ✅:
At higher probabilities (above 0.6), the model's predictions align more closely with the true probabilities, sticking to the diagonal line.
Well-Calibrated at High Confidence:
The model is well-calibrated for high probability predictions, showing it’s confident and accurate when predicting heart disease.
Potential Underestimation:
At lower probability levels, the model underestimates the likelihood of heart disease, which may affect predictions for borderline cases
The calibration curve indicates the model is generally trustworthy for high-probability predictions, making it reliable for clinical decision-making.
There's room for improvement at lower probability ranges to ensure better handling of uncertain or borderline cases. 🔧
In this heart disease prediction project, the decision threshold plays a critical role in balancing precision (minimizing false positives) and recall (capturing true positives). The default threshold of 0.5 may not be optimal for high-stakes scenarios like healthcare, where the stakes are life-saving.
Life-Saving Priority (High Recall):
In healthcare, maximizing recall is crucial to identify as many true heart disease cases as possible. A higher recall reduces the risk of missing critical cases but might lead to more false positives, resulting in additional tests.
Balancing Trade-Offs ⚖️:
Lowering the threshold increases recall but reduces precision, potentially leading to unnecessary anxiety or treatment. Raising the threshold improves precision but risks missing cases of heart disease (false negatives).
Customization for Safety:
In real-world healthcare systems, thresholds are often adjusted to prioritize patient safety, aiming for high recall (e.g., above 90%) while managing false positives.
Model's Potential in Healthcare:
ROC-AUC: High AUC score indicates excellent ability to distinguish between heart disease and no disease.
Precision-Recall Analysis: The model maintains strong precision while capturing a significant portion of true positive cases.
Calibration Curve: Predictions align well with actual outcomes, ensuring reliability in real-world applications.
While the default threshold of 0.5 offers a balanced approach, adjusting the threshold for specific scenarios (like healthcare) could further enhance the model’s performance, prioritizing life-saving recall and reducing false negatives. This could be done with careful attention to the trade-offs between precision and recall.
Threshold customization was not implemented here but is an important consideration for future work. By optimizing the threshold based on the Precision-Recall trade-offs, the model can become even more effective for applications where patient safety is paramount.
This project focused on developing a reliable heart disease prediction model using a Random Forest classifier. By utilizing techniques such as data preprocessing, SMOTE for handling class imbalance, hyperparameter tuning, and performance evaluation metrics, we were able to build a model with impressive predictive power.
High Performance: The model demonstrated strong performance across several metrics, including the ROC-AUC score, Precision-Recall Curve, and Calibration Curve, confirming its ability to effectively distinguish between patients with and without heart disease.
Accuracy with Trade-offs: While the complexity of heart disease detection introduces some trade-offs, the model achieves high accuracy with minimal compromises, balancing precision and recall for reliable predictions.
Threshold Optimization: Fine-tuning the decision threshold could further enhance the model’s effectiveness, particularly in healthcare scenarios where detecting true positives is crucial.
Clinical Integration: Future work could explore integrating the model into clinical workflows, ensuring it is practical and adaptable in real-world settings.
Validation with Larger Datasets: Expanding the dataset and validating the model on a broader scale would help refine its applicability in diverse healthcare environments.