You would have to use a section suppression formula like this:
(
not onlastrecord and
{table.groupfield} = next({table.groupfield}) and
{table.dischargedate} = next({table.admissiondate})
) or
(
not onfirstrecord and
{table.groupfield} = previous({table.groupfield}) and
{table.admissiondate} = previous({table.dischargedate})
)
I added in the group clauses, as I assumed you might be doing this within a group, e.g., on patientID.
-LB