Geographic access to US Neurocritical Care Units registered with the Neurocritical Care Society

Abstract

Background: Neurocritical care provides multidisciplinary, specialized care to critically ill neurological patients, yet an understanding of the proportion of the population able to rapidly access specialized Neurocritical Care Units (NCUs) in the United States is currently unknown. We sought to quantify geographic access to NCUs by state, division, region, and for the US as a whole. In addition, we examined how mode of transportation (ground or air ambulance), and prehospital transport times affected population access to NCUs.

Methods: Data were obtained from the Neurocritical Care Society (NCS), US Census Bureau and the Atlas and Database of Air Medical Services. Empirically derived prehospital time intervals and validated models estimating prehospital ground and air travel times were used to calculate total prehospital times. A discrete total prehospital time interval was calculated for each small unit of geographic analysis (block group) and block group populations were summed to determine the proportion of Americans able to reach a NCU within discrete time intervals (45, 60, 75, and 90 min). Results are presented for different geographies and for different modes of prehospital transport (ground or air ambulance).

Results: There are 73 NCUs in the US using ground transportation alone, 12.8, 20.5, 27.4, and 32.6% of the US population are within 45, 60, 75, and 90 min of an NCU, respectively. Use of air ambulances increases access to 36.8, 50.4, 60, and 67.3 within 45, 60, 75, and 90 min, respectively. The Northeast has the highest access rates in the US using ground ambulances and for 45, 60, and 75 min transport times with the addition of air ambulances. At 90 min, the West has the highest access rate. The Southern region has the lowest ground and air access to NCUs access rates for all transport times.

Conclusions: Using NCUs registered with the NCS, current geographic access to NCUs is limited in the US, and geographic disparities in access to care exist. While additional NCUs may exist beyond those identified by the NCS database, we identify geographies with limited access to NCUs and offer a population-based planning perspective on the further development of the US neurocritical care system.

Fig. 1

Specific time intervals and time stamps for prehospital transportation of a patient. Adapted with permission from prehospital emergency care by National Association of EMS Physicians (US) reproduced with permission of Hanley & Belfus, Inc. in the format Journal via Copyright Clearance Center

Fig. 2

National access to Neurocritical Care Units within 45 and 90 min of travel time for in-state and cross-state restrictions by either ground or with the addition of air ambulance