Correlation analysis of joint damages in rheumatoid arthritis. For each joint damage, we calculated the pairwise Pearson’s correlation from all other joint damages. Joints from finger, wrist, toe are shown in blue, orange, and green, respectively. The double lines represent joint space narrowing and the single line represents bone erosion. a, The correlation heatmap represents the correlations from the same side. b, The correlation heatmap represents the correlations from the other side.