Think about it this way: you want someone to design a website for you so you go off and find someone to do it. Now, you don't know how to program, don't really know anything about computers aside from how to perform a few functions (certainly nothing about how they actually work), and don't really have a professional frame of reference for evaluating the developers skill level.

This is basically what you have to deal with with doctors. There are doctors who are very, very good and doctors who are just barely bright enough to continue to practice. The major problem is how you distinguish between the two or, in other terms, how do you find a good programmer if you don't really know anything about programming? Honestly, I don't have an easily cut-and-dried answer. I generally rely on my family (a large subset of my family are highly skilled physicians) to use their professional expertise and circles to find a very highly respected physician in the area. Similarly, I generally help in evaluating technical issues for them.