Multi-state models are routinely used in research where change of status over
time is of interest. In epidemiology and medical statistics, for example, the
models are used to describe health-related processes over time, where status
is defined by a disease or a condition. In social statistics and in demography,
the models are used to study processes such as region of residence, work
history, or marital status. A multi-state model that includes a dead state is
called a multi-state survival model.