I don't have much information about either of those programs, but here is some advice that may or may not be helpful in making a decision. I was also torn... for me, it was prestige over price. Is there a cost difference for you between Northwestern and Rush? Each program has it's own "feel" too, and which one you're more comfortable and fit in best with can help.
In the end, having one year less probably won't make too much of a difference. If you feel like you may want the extra experience, then go with that. If you just want to get done, and Northwestern is a great (and rigorous!) program, then do that.
Here's one thing I did; I just sat down and laid out both in a list and in my mind all the pros and cons of each decision. I thought and tried to see how I "felt" about each decision... if you choose Rush, imagine attending there, the experiences, having to go an extra year but working in the hospital... then sit and imagine going to Northwestern, getting out a year early, the intensity, their "feel". Sounds corny but when you've exhausted yourself over a decision, at least for me, I was trying anything I could think of. It helped me figure out what looked "best" on the surface, and what decision was best for me overall and "felt" right, I knew I wouldn't regret it in 20-30 years down the road. And, if you make a decision, sit on it and don't tell anyone for a day or so, but make the decision, and see if after you've decided you start second-guessing and regretting. That can be revealing.
But honestly I'm an overthinker, and you will likely be happy going to either, but I would definitely consider finances!! I assume they are similar as you didn't mention, but that is certainly a factor.