Fig. 1
From: A technique for approximating transition rates from published survival analyses
State-transition diagram for illness-death model. State-transition diagram for an illness-death model. The model consists of three health states: healthy (h), ill (i), and dead (d). Variable names adjacent to the solid arrows are transition rates (\(\lambda _{hi}\), \(\lambda _{hd}\), and \(\lambda _{id}\)). This model is said to be “progressive” because transitions are irreversible (i.e. unidirectional). The curved arrows indicate that individuals can remain in a particular state over time. See text for more details