In this talk, Jasmine Wilkerson talks about the need for explainability in healthcare. Presented on 06/06/2019 **These slides are from a talk given at Rsqrd AI. Learn more at rsqrdai.org**

1. Jasmine Wilkerson
jasminewilkerson@gmail.com
Application of Explanation
Model In Healthcare

2. Agenda
• Why Explanation Model
• Which Explanation models
• Internal vs external application

3. Interpretable machine learning
• Explanations of AI/machine learning models to humans with domain knowledge
[Craik 1967, Doshi-Velez 2014]
• Why is the prediction being made?
• Comprehensible to humans in
• (i) natural language
• (ii) easy to understand representations

4. Why do we need explanation model?
• When fairness is critical:
• Any context where humans are required to provide explanations so that people cannot
hide behind machine learning models [Al-Shedivat 2017B, Doshi-Velez 2014]
• When consequences are far-reaching:
• Predictions can have far reaching consequences e.g., recommend an operation,
recommend sending a patient to hospice etc.
• When the cost of a mistake is high:
• Ex: misclassification of a malignant tumor can be costly and dangerous
• When a new/unknown hypothesis is drawn:
• “It's not a human move. I've never seen a human play this move.” [Fan Hui]
• Pneumonia patients with asthma had lower risk of dying [Caruana 2015]

5. Why do we need explanation model?
Well, the computer
assures me that you are
fine and it has given me
100 reasons for it.
Doctor, are you sure
that I am ok now? My
head still hurts.

6. Why do we need explanation model?
• Understanding end-to-end application criteria
o Who are the end users
o Scoring scenarios
o Engineering requirements
o Model Properties
Explanation Model Local
(n=1)
Global
(n=N)
Explanation Type Model Specificity
LIME X Relative Importance Agnostic
SHAP Kernel
Explainer
X X Relative Importance Agnostic
SHAP Tree Explainer X X Relative Importance Tree Based Models
GAM X Graphical Self
GA2M X Graphical Self
ICE Plots X Graphical Agnostic
Partial Dependence
Plots
X Graphical Agnostic
Model Distillation X Graphical Agnostic
Logistic Regression X Relative Importance Self
Decision Trees X Rules Self
XGB Explainer X Relative Importance XGBoost

7. Explanation Model Evaluation Criteria
Performance
• What is the acceptable tolerance of model performance (Precision, Recall, MAE, AUC etc)
Scalability
• Size of features
• Scoring Time
• Size of training set
Model Composition
• Ante-hoc: explanation are part of the models themselves
• Post-hoc: Explanations are generated by other techniques from the predictive model

8. Explanation Model Evaluation Criteria
Model Explanation Fidelity
• Does the explanation correspond to how the model is making the prediction
Model Specificity
• Is the explanation model specific to a particular ML model or can it be used
with all models
Risk
What is the risk associated with the outcome that is being predicted e.g., predicting end
of life incorrectly has a much higher associated risk as compared to predicting pharmacy
cost

9. Explanation Model Evaluation Criteria

10. Use cases
Data
MIMIC III ICU
Features
• Demographic
• Procedure
• Diagnosis
• Vital
• Lab
• Utilization
Prediction Model
Xgboost
Explanation Model
Shapley Value
Problem Statement:
Predict Length Of Stay of ICU encounters

11. Shapley Global Explanation - LOS

12. Shapley Global Explanation Correlation - LOS

13. Shapley Global Explanation Features Clusters - LOS

14. Shapley Local Explanation
Patient 1
Predicted LOS : 2.04
Actual LOS : 2.35
Patient 2
Predicted LOS : 13.21
Actual LOS : 15.21
Coronary atherosclerosis and other heart disease
Acute and unspecified renal failure
Congestive heart failure; nonhypertensive
Essential hypertension
Respiratory failure; insufficiency; arrest (ad...
Cardiac arrest and ventricular fibrillation
Acute myocardial infarction
Pneumonia (except that caused by tuberculosis ...
Congestive heart failure; non-hypertensive
Epilepsy; convulsions
Coma; stupor; and brain damage
Peripheral and visceral atherosclerosis
Respiratory failure; insufficiency; arrest (ad...
Hepatitis
Diverticulosis and diverticulitis

15. "We don't believe in artificial intelligence. We
believe in assistive intelligence. We leave the
decision on how to act in the hands of well-trained
experts, like the physicians.”
says Dr. Ankur Teredesai, CTO, KenSci Inc.

16. Thanks !!