In trying to find a good juxtaposition on the differences between development and relief in medical international aid work, there were two good google search results. The first was a chart produced by the Harding University, which is a Christian, Liberal Arts college in Arkansas. On the left are the attributes of development and the right are those of relief:
It's quite clear which one Harding University prefers, but this is also the belief of many who go into international aid. The general conceit is that limited (i.e. non-sustainable) programs are detrimental to the overall good of the population served - and that, reading between the lines, relief is paternalistic and self-absorbed act by the foreigner.
Countering this meme is the second good google search result, a 2006 PLoS article by Goorik Ooms, at that time the Executive Director of Doctors Without Borders - Belgium (MSF-B), in which he forsakes the necessity of long-term action for the immediacy of the benefits of relief work:
Medical relief organisations are not driven by health development approaches (such as supporting health as a human right, achieving the MDGs, or investing in health care for economic growth). Instead, they are driven by a humanitarian impulse; there are overwhelming needs and there is an obligation to respond to those needs...
...Health development advocates should not blame medical relief advocates for ignoring concerns about sustainability. The actions of medical relief agencies have nothing to do with ignorance; they are a deliberate choice. The status quo of insufficient public health budgets deserves only a firm rejection.
The point here isn't that development is a bad idea, though in fact there may be many terrible, even paternalistic, overtures in development ('we know how your society should look in 30 years better than you do'). Rather it's that today matters for a lot of sick patients and relief is the best way to get help to them. Development of health infrastructures requires a better educational system to produce more doctors/nurses/pharmacists/etc - which can take years. And requires a better governance system to employ resources without corruption - which can take years. And requires an improved economy to pay for education and health resources - which, again, can take years.
So in the meanwhile, what happens to those patients who are infirm or injured?