Predicting Acute Kidney Injury at Hospital Re-entry Using High-dimensional Electronic Health Record Data
This work addresses AKI prediction for rehospitalized patients, an incremental improvement focusing on a specific cohort to enhance risk assessment at hospital admission.
The study tackled predicting Acute Kidney Injury (AKI) at hospital re-entry for rehospitalized patients by leveraging high-dimensional EHR data, achieving predictions evaluated with cross-validation and calibration analysis on a dataset of 34,505 patients and 90,013 samples. The result included identifying modifiable risk factors like medications, with potential to inform a predictive tool for clinical use.
Acute Kidney Injury (AKI), a sudden decline in kidney function, is associated with increased mortality, morbidity, length of stay, and hospital cost. Since AKI is sometimes preventable, there is great interest in prediction. Most existing studies consider all patients and therefore restrict to features available in the first hours of hospitalization. Here, the focus is instead on rehospitalized patients, a cohort in which rich longitudinal features from prior hospitalizations can be analyzed. Our objective is to provide a risk score directly at hospital re-entry. Gradient boosting, penalized logistic regression (with and without stability selection), and a recurrent neural network are trained on two years of adult inpatient EHR data (3,387 attributes for 34,505 patients who generated 90,013 training samples with 5,618 cases and 84,395 controls). Predictions are internally evaluated with 50 iterations of 5-fold grouped cross-validation with special emphasis on calibration, an analysis of which is performed at the patient as well as hospitalization level. Error is assessed with respect to diagnosis, race, age, gender, AKI identification method, and hospital utilization. In an additional experiment, the regularization penalty is severely increased to induce parsimony and interpretability. Predictors identified for rehospitalized patients are also reported with a special analysis of medications that might be modifiable risk factors. Insights from this study might be used to construct a predictive tool for AKI in rehospitalized patients. An accurate estimate of AKI risk at hospital entry might serve as a prior for an admitting provider or another predictive algorithm.