"For many surgical procedures, operative mortality [death] rates are substantially lower at hospitals that perform them more frequently," the authors write in background information. "As a result, concentrating selected procedures in higher-volume hospitals is advocated by many. ... Previous analyses suggest that such regionalization policies could avert hundreds, if not thousands, of surgical deaths each year in the United States."
However, many worry that such policies would imply unreasonable travel burdens if patients, especially those in rural areas, were required to travel to higher-volume centers for surgery.
John D. Birkmeyer, M.D., of Dartmouth-Hitchcock Medical Center, Lebanon, N.H., and colleagues used national Medicare claims data and U.S. road network information to assess the travel time implications of setting minimum volume standards for two surgical procedures - pancreatic resection (removal or all or part of the pancreas) and esophagectomy (partial or total removal of the esophagus). Data were analyzed from 15,796 Medicare patients undergoing these two procedures between 1994 and 1999. These procedures were chosen for this study because they are usually scheduled electively and are performed infrequently enough that regionalization (limiting these procedures to certain hospitals) would not affect large numbers of patients, according to the authors. Also, the authors note that surgical death rates with each procedure were 12 percent higher at very low-volume hospitals than at very high-volume centers (16 percent vs. 4 percent for pancreatic resection, 20 percent vs. 8 percent for esophagectomy).
"With low-volume standards (1/year for pancreatectomy; 2/year for esophagectomy), approximately 15 percent of patients would change to higher-volume centers, with negligible effect on their travel times," the authors found. "Most patients would need to travel less than 30 additional minutes (74 percent pancreatectomy; 76 percent esophagectomy). Many patients (about 25 percent) already lived closer to a higher-volume hospital (25 percent pancreatectomy; 26 percent esophagectomy). Conversely, with very high-volume standards (more than 16/year for pancreatectomy; more than 19/year for esophagectomy), approximately 80 percent of patients would change to higher-volume centers. More than 50 percent of these patients would increase their travel time by more than 60 minutes. Travel times would increase most for patients living in rural areas."
"Many patients travel past a higher-volume center to undergo surgery at a low-volume hospital. If not set too high, hospital volume standards could be implemented for selected operations without imposing unreasonable travel burdens on patients," the authors conclude. (JAMA. 2003;290:2703-2708. Available post-embargo at JAMA.com)
Editor's Note: Dr. Birkmeyer is a paid consultant for the Leapfrog Group and serves as chair of its expert panel on evidence-based hospital referral. This study was supported by the Agency for Healthcare Research and Quality and the Center for Medicare & Medicaid Services.