Application type

When selecting target age demographics for an intervention, the HIIC allows users to specify whether selected target age-groups correspond to the age of the target population in the base year (cohort approach), or the age of the target population in future years (period approach).

Cohort approach

Interventions following the cohort approach are applied to individuals on the basis of their age in the starting year of the model (i.e. 2021). While individuals eventually 'age out' of the specified target_age, cohort interventions continue to be applied to individuals so long as they satisfied age-selection criteria in the starting year of the model. Critically, cohort interventions cease to be applied after all members of the cohort have passed away - even if this occurs before the implied end of the intervention as specfied through duration and time_lag inputs.

Period approach

Interventions following the period approach are applied to individuals on the basis of their age in future years. Period interventions begin to be applied to individuals once they have reached the lower-bound of the specified target_age, and cease to be applied once the individual exceeds the upper-bound of the specified target_age. Unlike cohort interventions, individuals may age 'in to' and 'out of' target age-groups to which an intervention is applied.