Not necessarily a collection call. Calls from patient rooms and doctors offices in the hospital dial out using the same phone number, as do St. John's Behavioral Health and St. John's Mercy Villa (nursing home). I just received two calls that turned out to be my cousin trying to reach my mother through me because my uncle is in the hospital. The same phone number shows on caller ID.
More than likely someone was trying to reach you about something other than a bill collection.