Explainable Machine Learning for Early Detection of Mild Cognitive Impairment, Fall Risk, and Frailty Using Sensor-Based Motor Function Data

This study aimed to design and evaluate an explainable machine learning (ML) framework that integrates sensor-based motor assessments with demographic and clinical data to identify early indicators of mild cognitive impairment (MCI), fall risk, and frailty in older adults. Eighty-three community-dwelling older adults (60 years or older) completed multimodal motor assessments using the Mizzou Point-of-Care Assessment System (MPASS) to capture synchronized gait, balance, and sit-to-stand performance. Sensor-derived motor features were combined with demographic and clinical variables to develop predictive models for MCI, frailty, and fall risk using XGBoost and Decision Tree algorithms. A unified multilabel framework was also developed using XGBoost, Decision Tree, and AdaBoost to predict all three outcomes. Model interpretability was evaluated using SHapley Additive exPlanations (SHAP). The ML model for MCI achieved the highest performance (94% accuracy, AUC = 0.88, F1 = 0.94), followed by fall risk (94% accuracy, AUC = 0.90) and frailty (82% accuracy, AUC = 0.77). Unified multilabel models showed moderate performance (67-73% accuracy), with XGBoost achieving the highest accuracy (73%), sensitivity, and F1 score, while the Decision Tree showed higher discrimination (AUC = 0.72). SHAP analyses identified stride length and time, center-of-pressure-based balance measures, and knee angular velocity during sit-to-stand as dominant predictors. This work introduces a novel ML framework using multimodal sensor-based motor assessments to predict MCI, fall risk, and frailty individually and within a unified model. By combining explainable ML with objective motor-function data, the framework supports transparent early screening of multidomain cognitive and physical decline in aging.