That's normal in Lancaster County. LCR is required to notify PD if EMS and/or fire are responding to a call within our jurisdiction. A lot of times, those notifications come while we're doing something else, and we can't go. A lot of times, they're of a nature where either we're going to be of no help (medically), or EMS will beat us to the call (Our EMS group is
quick to get to calls, especially the serious ones). We get a lot of those calls to doctor's offices, rehab/extended care facilities, etc. No point in clogging up the call when more qualified people are already there and more are on the way.
Honestly, our philosophy is that we have just enough training to be dangerous except at very serious calls, and we try to stay out of EMS/Fire's way. But we're great at carrying bags/equipment and retrieving same from the rigs.

and if they call for help, we get there in a hurry.
Times when you'll absolutely get a PD response: Unconscious/AED, violent/combative patient; anything moderately serious involving a child. My agency's protocol for EMS is to respond to all class 1 calls unless they're at a medical facility or other situation where a provider is already on the scene. I won't say we go to all of them but we try, especially if it sound serious or there are issues we know about.
As for fire calls, I usually go just because we'll beat Fire and we can give updates if needed or start other responses. I encourage my officers to do the same. A lot of times we end up leaving shortly thereafter.
We are blessed in my area with a great working relationship with EMS and Fire. And they are quality, well-trained folks that I'm glad to have around. Makes all of our jobs a LOT easier.