Fig. 4: Chord diagrams showing the patterns of one-step multimorbidity progress among ICD-10 chapters by sex and progress direction.

a females, uni-directional progress. b males, uni-directional progress. c females, bi-directional progress. d males, bi-directional progress. The blue arcs represent the amount of uni-directional one-step multimorbidity that progresses from one chapter to another chapter following the direction of the arrows. The red arcs represent the amount of bi-directional one-step multimorbidity that progresses between two chapters. The thicker the arcs, the larger the amount. Fragments going around the circumference represent the total amount of one-step multimorbidity in the chapter. Arcs without inner lines represent self-links. Only pairs with effect sizes larger than 0.01 are counted.