Fig. 1.

Outline of Markov model. Single conditions: states include diabetes mellitus, coronary heart disease, stroke or colorectal cancer; dual conditions: states include each potential combination of two of these four conditions; triple conditions: states include each potential combination of three of these four conditions; quadruple conditions: state includes all four conditions combined. Individuals in any state may reversibly transition to comorbid depression (not shown) or irreversibly to death. Arrows indicate transitions between states.