In our case our pediatrician doesn't communicate well (at all) with the CF clinic. And they're the worst about calling back. I'm still waiting for that call back from last October about H1N1 vaccine availability... <img src="i/expressions/face-icon-small-sad.gif" border="0">
And although our cf clinic is 250 miles away, I usually get a call back within a few hours and even if it isn't anything urgent -- such as a question about a medication -- switching from liquid to capsules -- the nurse calls me by the end of the day to keep me informed that they're checking on it and will get back to me in the morning.
And after hours, I call the CF clinic, his service calls him and usually within half an hour the doctor calls me back.