According to Spiegel in "Too Much of a Good Thing: Choking on Aid Money in Africa", the Washington Center for Global Development calculated that it would require $3,521 of marginal development aid invested, per person, in order to increase per capita yearly income by $3.65 (one penny per day).
The Kenyan economist James Shikwati is even more pessimistic in "For God's Sake, Please Stop the Aid!": The net effect of Western aid to Africa is actively destructive (even when it isn't stolen to prop up corrupt regimes), a chaotic flux of money and goods that destroys local industry.
What does aid to Africa have in common with healthcare spending? Besides, of course, that it's heartbreaking to just say no -