If the column is always dependant, and you're using a DBMS that supports it, you can use a computed column. For SQL Server, that looks like:
alter table YourTable
add YourColumn as
(
case
when OtherColumn like '%Health%' then 'HLTH'
else 'Default'
end
)
To add a real column with values, you could use a two-step approach. After adding the column:
alter table YourTable
add YourColumn varchar(5)
Run an update query to set its value:
update YourTable
set YourColumn =
case
when OtherColumn like '%Health%' then 'HLTH'
else 'Default'
end
That should initialize the new column. But unlike the computed column, it's now up to you to maintain it.