I can only use Portsmouth hospital for an example because that's where I volunteered and I know a ton of people who worked there. Some of the people I knew did live in Portsmouth or the surrounding towns like rye and new castle but a lot of the people lived in Dover,Durham, Rochester, Barrington,Lee,madbury,heck even Strafford and commuted in. I know for a fact that for awhile Portsmouth hospital had a rule that if you worked in a job that requires you to be on call you either had to live within so many miles of the hospital or stay in house(meaning sleep in the hospital) if you were on call.

One of my friends mentioned that she could leave the hospital and do things within Portsmouth when she was on call but she was required to be within a 20 minute drive from the hospital so she couldn't go far