
38 Discrete Event Simulation for Health Technology Assessment
This is clearly wrong as half the individuals should be treated. By simulating
the individuals instead of the group, these problems due to heterogeneity are
averted.
The number of factors that must be considered because they determine
what happens is commonly high in HTA models. As this number rises, the
inaccuracies multiply if a cohort is modeled and heterogeneity is ignored.
Keeping track of what has happened to each person during a simulation is
important in models of human illness because the past is usually a determi-
nant of the future. For example, the risk of fracture in a person ...