One of the perceived limitations in achieving a successful outcome for a patient requiring transfer is the potential opportunity cost of awaiting transfer. When no organized system of care exists specifically for the care of ruptured abdominal aortic aneurysm, emergency department (ED) death can occur when local treatment is unavailable. Although some of these ED deaths encompass those who arrive in extremis, a percentage of these deaths also reflect those who deteriorate while awaiting definitive care [2]. A recent study using the Nationwide Emergency Department Sample (NEDS) data found 7 % of patients died in the ED and another 6 % admitted to the presenting hospital died without treatment. It is not possible from the NEDS dataset to determine exactly why patients died in the ED or were not offered transfer; however, one can hypothesize that these patients were either in extremis on presentation precluding transfer or worsened while awaiting transfer. The study suggests that the later explanation may be a larger factor as those more likely to have an ED death included those who were older and who presented to nonmetropolitan hospitals (Table 10.1). Nonmetropolitan hospitals were also most likely to transfer patients. The high ED death rate and transfer rate may imply that these facilities were not able to provide local care. Without a rapid and reliable transfer process, a percentage of these deaths are likely preventable with better regional systems of care.

The need for predefined transfer plans may be even more important in geographic regions where the land mass to hospital facility ratio is greatest. The NEDS study also identified differences in ED death by region. The West had almost double the ED death rate even after adjusting for demographic and hospital factors. Further underscoring the difficulties with transfer across larger geographic constraints, the West was also the least likely to transfer patients. As the Western Region of the United States has approximately 25 % of the US population but 50 % of the land mass, our findings suggest that patients who have greater travel distances and travel times to the initial ED may be more likely to become clinically unstable upon arrival or before transfer can be arranged (REF).

In the current era of publically reported outcomes, many centers remain concerned about the implications on overall institutional mortality when accepting high-risk patient transfers. In the case of ruptured abdominal aortic aneurysms, single-center studies have reported equivalent outcomes for treatment of ruptured abdominal aortic aneurysm after transfer [3–7]. However, in these studies only those receiving treatment for their aneurysm were included. Thus, those transferred who did not undergo treatment or who died prior to reaching the receiving hospital were not captured These studies suffer from survivor bias given that patients had to survive transfer and be stable enough for treatment on arrival.

This limitation was addressed in a follow-up study using an intent-to-treat analysis linking State Inpatient Databases and Emergency Department Databases for New York, California, and Florida to compare outcomes for ruptured abdominal aortic aneurysm between those transferred for care with those treated at the presenting institution [8]. Almost 20 % of patients were transferred for definitive care (REF). Most patients were transferred a short distance (median, 27 miles), and few (<8 %) traveled great distances defined as >100 miles. The study found equivalent mortality rates for those transferred (45 %) patients to those treated without transfer (43 %). Unfortunately, among those transferred, 17 % still died without receiving treatment. When accounting for these patients in the intent-to-treat analysis, transfer was actually associated with an increased mortality (Table 10.2).

Although transfers were more common on weekends, mortality was independent of time of presentation. One of the interesting findings was the annual increase in transfer rates over time from 15 % in 2005 to 24 % in 2010. Transferred patients had fewer comorbid medical conditions and were more likely to present to smaller nonteaching hospitals. These findings further support the hypothesis that those most likely to benefit from transfer are those that are stable enough to receive an operation when they arrive at the receiving facility. Establishing transfer guidelines is unlikely to benefit those who are in extremis at the initial treating facility, but likely will have the greatest impact on those patients who are harmed by delays in care that convert them from stable to potentially unstable while awaiting transfer. The key finding thus far is that the benefits of the current de facto transfer process seen on a population level could be interpreted that transfer is associated with a higher mortality; the alternative and likely more accurate summation is that attention should be focused on improving the transfer process to increase the likelihood of clinical stability during transfer and consequently improve overall survival [9].