I have also worked at a Level 1 Trauma hospital, and I think it depends on the distance from the hospital and the degree of specialty care needed. Also, since Covid, there have been more and more staffing and capacity problems in ERs. Taking a critical patient to an ER with no available resus bays that is also boarding ICU patients due to a lack of ICU staffing is going to be less effective and less safe than going the extra distance to a hospital that does have the capacity to care for the patient. Studies from before 2020 are just not relevant anymore.
I have also worked at a Level 1 Trauma hospital, and I think it depends on the distance from the hospital and the degree of specialty care needed. Also, since Covid, there have been more and more staffing and capacity problems in ERs. Taking a critical patient to an ER with no available resus bays that is also boarding ICU patients due to a lack of ICU staffing is going to be less effective and less safe than going the extra distance to a hospital that does have the capacity to care for the patient. Studies from before 2020 are just not relevant anymore.