ICER is calculated by dividing the difference in costs between two possible interventions by the difference in their effectiveness. The formula is:
\[ ICER = \frac{C_1 - C_0}{E_1 - E_0} \]
Where: - \(C_1\) and \(C_0\) are the costs of the new and standard interventions, respectively, - \(E_1\) and \(E_0\) are the effectiveness measures of the new and standard interventions, respectively.