Application of machine learning approaches to administrative claims data to predict clinical outcomes in medical and surgical patient populations.

OBJECTIVE: This study aimed to develop and validate a claims-based, machine learning algorithm to predict clinical outcomes across both medical and surgical patient populations. METHODS: This retrospective, observational cohort study, used a random 5% sample of 770,777 fee-for-service Medicare beneficiaries with an inpatient hospitalization between 2009-2011. The machine learning algorithms tested included: support vector machine, random forest, multilayer perceptron, extreme gradient boosted tree, and logistic regression. The extreme gradient boosted tree algorithm outperformed the alternatives and was the machine learning method used for the final risk model. Primary outcome was 30-day mortality. Secondary outcomes were: rehospitalization, and any of 23 adverse clinical events occurring within 30 days of the index admission date. RESULTS: The machine learning algorithm performance was evaluated by both the area under the receiver operating curve (AUROC) and Brier Score. The risk model demonstrated high performance for prediction of: 30-day mortality (AUROC = 0.88; Brier Score = 0.06), and 17 of the 23 adverse events (AUROC range: 0.80-0.86; Brier Score range: 0.01-0.05). The risk model demonstrated moderate performance for prediction of: rehospitalization within 30 days (AUROC = 0.73; Brier Score: = 0.07) and six of the 23 adverse events (AUROC range: 0.74-0.79; Brier Score range: 0.01-0.02). The machine learning risk model performed comparably on a second, independent validation dataset, confirming that the risk model was not overfit. CONCLUSIONS AND RELEVANCE: We have developed and validated a robust, claims-based, machine learning risk model that is applicable to both medical and surgical patient populations and demonstrates comparable predictive accuracy to existing risk models.

Evaluation of a new circuit configuration for the VDR-4 high-frequency percussive ventilator.

High-frequency percussive ventilation (HFPV) by the VDR-4(R) has been a successful mode of ventilation in the management of inhalation injuries for nearly 20 years. A limitation of the standard VDR-4 ventilator circuit is that the sliding venturi manifold is heavy in weight and is normally connected directly to the patient's endotracheal tube (ETT), resulting in potentially hazardous torque on the ETT. In this study, we evaluate the mechanics of a new circuit for the VDR-4 that relocates the sliding venturi manifold portion of the circuit away from the ETT into the ventilator proper. This new VDR-4 circuit configuration may have an important impact on patient safety.