How about adding function to compare the cost on the treatment?
When we compare the cost between target vs. comparator cohort (eg., phenytoin cohort vs. levetiracetam cohort),we can compare the cost for the medicine itself (we can calculate whole cost for phenytoin and levetiracetam in the cohort by using āincluding concept_id for treatment costā function to the cost estimation package).
Since levetiracetam is more expensive than phenytoin, I want to compare the expense of the treatment, too.