Figure 2. Graphic description of the study. (A) 4,846 entries from CHARLS were used to train a deep neural network regressor of chronological age, whose performance was compared to an elastic net model. The age predicted by a regressor is further referenced as “biological age”. Biological age of healthy (test set) participants and participants with a history of serious diseases (discovery set) was compared to identify conditions that are interpreted as accelerated aging by the model. To control for confounders, prediction averages were compared in matched cohorts. (B) The effect of psychological and other factors has been compared using elastic net. All variables, except chronological age, were converted to binary to predict biological age returned by the neural network described in panel (A). The weight of each variable was interpreted as age acceleration.