Well you should only have 10 Special Clinics and 5 Back to work schools. I know it doesn't seem like much, but it will get you all of the workers you possibly can (it did me)
As for Health index; It isn't like the education index. Education, if you have twice the number of schools needed, then your index is 200, 1.5 more than needed 150 index, Etc.
Health on the other hand is not so. Actually, if one where to have the exact Number of Hospitals needed, then your index would only amount to about 94, if twice the number, around 160. Therefore, Health DOES NOT share a 1 to 1 relationship with its index.
Moral of the story? Maintaining a high Health Index is very demanding on a country's economy because of the primary expenditures of the actual Health System, and the secondary expenditures of the Social Security System.
an index of 200 to 250 is therefore unrealistic for most countries (unless you have tens of millions of people, maybe then it would be possible) Still, you are correct in stating the higher the index the better the death rate (and also the birth rate) so you get more population.