What would be the effect of referral to high-volume hospitals in a largely rural state?

CONTEXT: Volume of certain surgical procedures has been linked to patient outcomes. The Leapfrog Group and others have recommended evidence-based referral using specific volume thresholds for nonemergent cases. The literature is limited on the effect of such referral on hospitals, especially in rural areas.
PURPOSE: To examine the impact of evidence-based referral by volume standard for 5 hospital procedures (abdominal aortic artery repair, coronary angioplasty, coronary artery bypass graft, esophageal cancer surgery, and pancreatic resection) in a largely rural state.
METHODS: Healthcare Cost and Utilization Project Iowa State Inpatient Dataset was analyzed to identify hospitals meeting the volume standard versus those not meeting the standard.
FINDINGS: Relatively few hospitals perform these procedures in Iowa. Hospitals performing the procedures at a volume above the threshold standard set by the Leapfrog Group tend to be larger, receive more transfers from other hospitals for these procedures, and perform fewer of these procedures on an emergency basis. In Iowa, hospitals that met the volume standard did not differ from hospitals that did not meet the volume standard in risk-adjusted mortality rates. The impact of evidence-based referral would be substantial in terms of travel time for some procedures (ie, coronary artery bypass graft, pancreatic resection, and esophageal cancer surgery) and produce considerable lost revenue for some hospitals.
CONCLUSIONS: Evidence-based referral would be associated with substantial burden for some patients and hospitals in Iowa. This negative impact does not appear to be offset by improvement in in-hospital mortality rates. These initial findings suggest that there are a number of issues that need to be considered, especially in a rural state, before evidence-based referral is embraced as a means to enhance patient outcomes.