Strategies to Mitigate Model Drift of a Machine Learning Prediction Model for Acute Kidney Injury in General Hospitalization

Background: Model drift is a major challenge for applications of clinical prediction models. We aimed to investigate the effect of two strategies to mitigate model drift based on a previously reported prediction model for acute kidney injury (AKI).

Methods: Deidentified electronic medical data of inpatients in Sichuan Provincial People’s Hospital from January 1, 2019, to December 31, 2022, were collected. AKI was defined by the KDIGO criteria. The top 50 laboratory variables, alongside with sex, age, and the top 20 prescribed medicines were included as predictive variables. In model optimization, the convolution neural network module was replaced by a self-attention module. Periodical refitting with accumulative data was also conducted before temporally external validations. The performance of the innovated model (ATRN) was compared with the previous model (ATCN) and other four models.

Results: A total of 150,373 admissions were identified. The annual incidences of AKI varied between 5.57% and 5.8%. The performance of the models which had used temporal features profoundly declined over time. The ATRN model with module more suitable to capture short-term time dependencies outperformed the other five models both in C-statistics and recall rates perspectives. Periodic refitting the prediction model with accumulative data also helped to effectively mitigate the model drift, especially in models with time series data.

Conclusions: Enhancing the model’s ability to capture short-term time dependencies in time series data and periodic refitting with accumulative data were both capable of mitigating the model drift. The best improvement of model performance was observed in the combination of these two strategies.