Department of Emergency Medicine, University of Cincinnati, Cincinnati, OH; UC Health Air Care & Mobile Care, Cincinnati, Ohio.
Department of Decision and Technology Analytics, Lehigh University, Bethlehem, PA; Lehigh University College of Health, Bethlehem, PA.
Air Med J. 2024 Mar-Apr;43(2):111-115. doi: 10.1016/j.amj.2023.11.002. Epub 2023 Nov 25.
Interhospital transfer by air (IHTA) represents the majority of helicopter air ambulance transports in the United States, but the evaluation of what factors are associated with utilization has been limited. We aimed to assess the association of geographic distance and hospital characteristics (including patient volume) with the use of IHTA.
This was a multicenter, retrospective study of helicopter flight request data from 2018 provided by a convenience sample of 4 critical care transport medicine programs in 3 US census regions. Nonfederal referring hospitals located in the home state of the associated critical care transport medicine program and within 100 miles of the primary receiving facility in the region were included if complete data were available. We fit a Poisson principal component regression model incorporating geographic distance, the number of emergency department visits, the number of hospital discharges, case mix index, the number of intensive care unit beds, and the number of general beds and tested the association of the variables with helicopter emergency medical services utilization.
A total of 106 referring hospitals were analyzed, 21 of which were hospitals identified as having a consistent request pattern. Using the hospitals with a consistent referral pattern, geographic distance had a significant positive association with flight request volume. Other variables, including emergency department visit volume, were not associated. Overall, the included variables offered poor explanatory power for the observed variation between referring facilities in the use of IHTA (r = 0.09). Predicted flights based on the principal component regression model for all referring hospitals suggested the majority of referring hospitals used multiple flight programs.
Geographic distance is associated with the use of IHTA. Unexpectedly, most basic hospital characteristics are not associated with the use of IHTA, and the degree of variation between referring facilities that is explained by patient volume is limited. The evaluation of nonhospital factors, such as the density and availability of critical care or advanced life support ground emergency medical services resources, is needed.
美国的空中（直升机）院际转运（IHTA）主要用于转运患者，但评估哪些因素与 IHTA 的使用相关的研究有限。我们旨在评估地理距离和医院特征（包括患者量）与 IHTA 使用之间的关系。
这是一项多中心、回顾性研究，纳入了来自美国 3 个地区的 4 个重症监护转运医学项目的直升机飞行请求数据。如果有完整的数据，非联邦转诊医院位于相关重症监护转运医学项目所在州内，且位于该地区主要接收医院 100 英里范围内，则纳入研究。我们拟合了包含地理距离、急诊就诊量、出院量、病例组合指数、重症监护病房床位数、普通床位数的泊松主成分回归模型，并检验了这些变量与直升机紧急医疗服务使用之间的关系。
共分析了 106 家转诊医院，其中 21 家为有一致请求模式的医院。使用具有一致转诊模式的医院，地理距离与飞行请求量呈显著正相关。其他变量，包括急诊就诊量，与飞行请求量无关。总体而言，纳入的变量对观察到的转诊医院之间在 IHTA 使用方面的差异解释能力有限（r = 0.09）。基于主成分回归模型对所有转诊医院进行预测，表明大多数转诊医院使用多个飞行项目。
地理距离与 IHTA 的使用相关。出乎意料的是，大多数基本医院特征与 IHTA 的使用无关，且患者量可解释的转诊医院之间的差异程度有限。需要评估非医院因素，如重症或高级生命支持地面紧急医疗服务资源的密度和可用性。
