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JSM 2013

Presented at a contributed SPEED session at the Joint Statistical Meetings, August 2013. Accompanying poster is available at http://z.umn.edu/jsm2013poster

Julian Wolfson

on 7 August 2013

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Transcript of JSM 2013

Censored Bayesian Networks
Predicting 5-year risk of cardiovascular events using electronic health record data.
Combines health information from clinic/hospital visits, prescription database, and vital records.
Bayesian network
A machine learning technique often used for classification problems.
2. Use assumptions on P(X|Y) to make life easier, e.g., independence = "Naive Bayes":
Electronic health record (EHR)
Censored Bayesian networks
Huge sample sizes
Incomplete follow-up and censoring
Missing data
Complex interactions
Opportunities and challenges
Our dataset provides 10 years of health information on >400,000 people.
BP, cholesterol, etc. measured irregularly (if at all), especially among young people.
CVD is multifactorial and several risk factors may interact.
Extending Naive Bayes to censored, time-to-event data
Naive Bayes assumption &
nonparametric smoothing
Kaplan-Meier estimator
Julian Wolfson, Assistant Professor, Division of Biostatistics
University of Minnesota School of Public Health
(in collaboration with the UMN/HP iPredict Research Group)
julianw@umn.edu z.umn.edu/julianw @DrJWolfson

1. Model class probabilities by applying Bayes' rule:
Yep, this assumption is pretty crazy. Amazingly, Naive Bayes often works pretty well even if the assumption is severely violated!
At the poster session this afternoon:
An app which uses these methods to calculate your five-year cardiovascular risk.
Full transcript