Changing Cycle Lengths in State-Transition Models: Doing it the Right Way

iNTRODUCTiON State-transition models (STMs) are commonly used in health care to inform funding and reimbursement decisions of new technologies, to optimize the use of limited resources, or to guide public health policies. These models typically simulate progression of events (e.g. disease stage, death) that evolve over time under some uncertainty. The common applications of STMs stipulate that time advances in fixed discrete steps known as cycles (e.g. month or year), and state transitions occur only at the beginning or end of a cycle.