How often does the interviewer not follow up?

I had an interview in August. The interviewer said she would let me know if I got the job in a few weeks. Never heard a thing. Another job interview that I had in August, I received an email that I didn't get the job. Recently I had quite a few interviews but I haven't heard anything back yet. Is it up to me to call HR and see if they made a decision? Part of me is scared to call because I have a feeling I wasn't picked. Every time I am rejected from a job a little part of me that was proud about finishing nursing school seems to disappear. Wouldn't I have received a call or email by now? How long do you wait until you call HR? I told my mom that some interviewers never let me know if I got the job or not and she was shocked. She said she couldn't believe people would be that rude. Is it too much to ask for an email at least? Or should I try to track these people down even though they said they would contact me?
Whenever you have an interview you should follow up with a thank you letter or email thanking them for the interview.If you don't hear back in a week or so, then it does no harm for you to follow up. It is not rude of them to not follow up if they decide not to hire you.
Reviewers not following up seems to be the trend lately...guess they figure with so many applicants beating their doors down, they don't need to bother When I was hunting, if I didn't hear anything within a week, I'd drop an e-mail or call to follow up: I'd say that I was checking on the status of my application and ask if they needed anything more from me. That usually got them moving one way or another...but if they still didn't follow up with me in the weeks after that, I figured I hadn't gotten the job and moved on.
Someone gave me this advice - near the end of the interview confidently ask when you should expect to be notified of their decision. It is direct and gives you a timeline for follow up if you do not hear back by that time.Doesn't really help for the interviews you have already gone to, sorry! I do think it is important to follow up soon after an interview with a thank you note and also with a call within a week or so of the interview.Good Luck!