Fig. 5.

Distribution of the actual progressors in the screening model ranking (based on 2-year follow-up). Patient categories are represented with colours. Subfigure A compares four categories: no progression (N), only pain-related progression (P), only structure-related progression (S), and combined progression (P ​+ ​S). Subfigures B and C compare two categories: all pain-related progression (P∪P ​+ ​S) vs. others (N∪S), and all structure-related progression (S∪P ​+ ​S) vs. others (N∪P). The top (highest) rank is 1. The distribution of ranks within each category is summarised with a box plot. The box edges mark lower and upper quartiles, with median shown in the middle, and whiskers indicate the minimum and maximum rank.