222 Discrete Event Simulation for Health Technology Assessment
6.4.1 Role of Predictors in the Equation
The factors included in an equation are all predictors in the sense that any
change in their values leads to a different prediction for the individual mod-
eled in the DES. The rst step is to list all potential predictors and ascertain
their expected role in the equations in relation to the response variables.
A predictor may play several roles, which are not necessarily mutually
exclusive.
The most obvious role is as determinants of the response. In an HTA, the
most important determinant has to do with the intervention that is under
assessment. Other determinants are included, however, because they pro-
vide for a more precise estimate o