Prediction of Acute Kidney Injury With a Machine Learning Algorithm Using Electronic Health Record Data

Abstract

Background: A major problem in treating acute kidney injury (AKI) is that clinical criteria for recognition are markers of established kidney damage or impaired function; treatment before such damage manifests is desirable. Clinicians could intervene during what may be a crucial stage for preventing permanent kidney injury if patients with incipient AKI and those at high risk of developing AKI could be identified.

Objective: In this study, we evaluate a machine learning algorithm for early detection and prediction of AKI.

Design: We used a machine learning technique, boosted ensembles of decision trees, to train an AKI prediction tool on retrospective data taken from more than 300 000 inpatient encounters.

Setting: Data were collected from inpatient wards at Stanford Medical Center and intensive care unit patients at Beth Israel Deaconess Medical Center.

Patients: Patients older than the age of 18 whose hospital stays lasted between 5 and 1000 hours and who had at least one documented measurement of heart rate, respiratory rate, temperature, serum creatinine (SCr), and Glasgow Coma Scale (GCS).

Measurements: We tested the algorithm's ability to detect AKI at onset and to predict AKI 12, 24, 48, and 72 hours before onset.

Methods: We tested AKI detection and prediction using the National Health Service (NHS) England AKI Algorithm as a gold standard. We additionally tested the algorithm's ability to detect AKI as defined by the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. We compared the algorithm's 3-fold cross-validation performance to the Sequential Organ Failure Assessment (SOFA) score for AKI identification in terms of area under the receiver operating characteristic (AUROC).

Results: The algorithm demonstrated high AUROC for detecting and predicting NHS-defined AKI at all tested time points. The algorithm achieves AUROC of 0.872 (95% confidence interval [CI], 0.867-0.878) for AKI detection at time of onset. For prediction 12 hours before onset, the algorithm achieves an AUROC of 0.800 (95% CI, 0.792-0.809). For 24-hour predictions, the algorithm achieves AUROC of 0.795 (95% CI, 0.785-0.804). For 48-hour and 72-hour predictions, the algorithm achieves AUROC values of 0.761 (95% CI, 0.753-0.768) and 0.728 (95% CI, 0.719-0.737), respectively.

Limitations: Because of the retrospective nature of this study, we cannot draw any conclusions about the impact the algorithm's predictions will have on patient outcomes in a clinical setting.

Conclusions: The results of these experiments suggest that a machine learning-based AKI prediction tool may offer important prognostic capabilities for determining which patients are likely to suffer AKI, potentially allowing clinicians to intervene before kidney damage manifests.

Keywords: acute kidney injury; machine learning.

Conflict of interest statement

Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Mohamadlou, Barton, Calvert, Lynn-Palevsky, Saber, and Das are employees of Dascena, developers of the predictive algorithm. Shieh reports receiving grant funding from Dascena.

Figures

Figure 1.

Inclusion criteria for patients in the BIDMC and Stanford data sets. Note. Patients who met all inclusion criteria were included in this study. BIDMC = Beth Israel Deaconess Medical Center. aRequired measurements include heart rate, respiratory rate, temperature, Glasgow Coma Scale, and serum creatinine.

Figure 2.

Comparison of the receiver operating characteristic and area under the receiver operating characteristic for machine learning algorithm 0-, 12-, 24-, 48-, and 72-hour advance prediction of stage 2 or stage 3 acute kidney injury development for BIDMC patient data. Note. BIDMC = Beth Israel Deaconess Medical Center.

Figure 3.

Comparison of the receiver operating characteristic and area under the receiver operating characteristic for machine learning algorithm 0-, 12-, 24-, 48-, and 72-hour advance prediction of stage 2 or stage 3 acute kidney injury development for Stanford Medical Center patient data.