Another aspect of the issue that could not be verified by McCoy's project is whether the findings hold true for mortality after patients are discharged from the hospital, perhaps to a skilled nursing care or hospice setting. The research was only able to review in-hospital death rates.
"We're just at the early stage," he says. "A long time ago, we didn't really know that heart patients benefitted from timely response times or chest compressions. It was only after researchers studied populations that they could separate out which patients benefitted from immediate care, and that's where we're at with this."
Another issue for health policy makers, hospitals, physicians and emergency response teams is the varying structure of 911 response teams, which may be owned or operated by private for-profit or non-profit organizations, municipal governments or counties, and not hospitals.
In those different organizational structures, resource and personnel variation may influence response times that could turn the data upside down. It's important for EMS systems, with their base hospital collaborators, to identify patients that may be helped by more rapid transport.
"In particular," the report says, "scene time (time spent treating the patient at the scene prior to transport) is the out-of-hospital interval that EMS systems have the most power to control, given that this interval is composed of evaluation and management that is guided by local EMS policy, procedures and protocols."