By virtue of the population that surrounds our university medical center, most of the patients we see are from underserved areas (the worst parts of Chicago). More times than not patients are Medicaid/public aid patients.
On the plus side, these people really, really need healthcare. I imagine that working with this population on a daily basis would leave you with a pretty healthy feeling of satisfaction. Quality healthcare is such a valuable resource, and when you make it available to people who have almost nothing you can literally transform lives. The poor 6 year-old kid who's terrible asthma was poorly controlled can now go to class and only miss 1-2 days each year rather than 20-30, all because you got him set up with a good medication regimen. It's the emotional stuff that gets made fun of in the personal statement threads, but in my experience that really isn't far off from what it's like.
However, there are also many frustrations, and it's dealing with things like this that have turned me off to dedicating my career to the underserved. No-show rates are extremely high in clinic. A good day would be 75% of patients that made appointments showing up. The result of this is that many patients never come for regular check-ups, and in the peds population specifically they get behind on vaccinations, don't have meds, etc. so when they show up for their school physical, they look like garbage. And it really comes down to the fact that those people either don't take responsibility for caring for themselves and/or their kids, or it is simply too taxing to do so. You also have to deal with bureaucracy to a much larger degree - physicians are limited in the drugs they can prescribe because of restrictions on what will be covered by public aid. It can be difficult or impossible to get timely referrals. Patients who have been waiting 6 months for that colonoscopy then decide not to show up - rinse and repeat, and 5 years has gone by and they STILL have not gotten an intervention that is clearly demonstrated to reduce morbidity and mortality. You argue with medical directors at the state office trying to convince them why a patient needs a particular test outside of the usual algorithm. And no, this is not something that is done by the office nurse or some other department - this is YOUR TIME.
It sounds callous, but at the end of the day I don't think I could work in that kind of environment without getting extremely frustrated, cynical, and angry - not necessarily at my patients, but at "the system" which you clearly see is NOT looking out for your patients' best interests. And yet, you cannot do anything about it - even if you're going to see a patient for free, so what? What if they need labs, medications, procedures, or other interventions done? The likelihood that those outside entities will also do their portion of care for free is almost zero. With some patients it is very much an exercise of banging your head against the wall, hoping that one day the wall will finally crumble down. However, in many cases it doesn't seem like it ever does.
Don't get me wrong, this is a job that needs to be done, and it is so, so important to the people that receive that care. But I think a certain personality is required to work in that kind of environment to avoid going completely psychotic after a few years. Politicians and others claim that people on Medicaid and other public aid get "all the care they need" and this other nonsense, but when you see how it actually works it becomes patently obvious that that really is not at all what's happening. The system needs to change, but unfortunately I myself do not have it in me to be that change. If that sounds appealing to you, though, then you would likely enjoy working in that kind of environment and with that population.