more functional take on the discussion; 3 required things

1. some sense of (a) how other researchers come to a conclusion (what their conclusion is and how they got there), and then (b) not only what your conclusion is, but also how you arrived at that conclusion, with "because" statements for (a) and (b); how you reason with and against other available positions in the field 
2. how your conclusion is (in)consistent with the field of public health at large, how it "fits" or doesn't "fit in" and "where"
3. some sense of a context that would put your reasoning in question; something that at least complicated (b) the way that you arrived at your conclusion or (a) your conclusion itself, that is, so that the reader can get a sense that you acknowledge that your results is just one results among other various results, and that your results is limited to a context at one time and in one place