Figure 4. Model Performance Evaluation. A.

Joint space narrowing could not be predicted with high accuracy using baseline clinical variables. Data from follow-up visits improved predictive performance. Models built to predict progression in both knees simultaneously were more accurate than those built for the right and left knees separately. B. Pain progression could be predicted with high accuracy using data from a single visit. Models to distinguish worsening or improving subjects from stable ones were moderately accurate, whereas those distinguishing worsening from improving ones were highly accurate.