Lead author Rachel Patzer, an assistant professor of surgery at Emory University School of Medicine in Atlanta, analyzed data on kidney transplants as reported by dialysis facilities to the Centers for Medicare and Medicaid Services from 2007 to 2010.
Four-year average standardized transplant ratios ranged from .69 in the Southeast to 1.61 in New England. Standardized transplant ratios represent the number of observed transplants to the number of transplants expected based on the number of end stage renal disease patients in a dialysis facility.
"A variety of factors contributed to this disparity," Patzer said in a statement.
"Understanding the modifiable factors should help us develop better interventions to improve access to transplantation."
The study, published in the American Journal of Transplantation, found lower standardized transplant ratios were associated with for-profit status of dialysis facilities, facilities with a higher percentage of African-American patients, patients with no health insurance and patients with diabetes.
Higher ratios were associated with more facility staff, more transplant centers, a higher percentage of employed patients and more patients who used peritoneal dialysis -- uses the patient's peritoneum in the abdomen as a membrane across which fluids and dissolved substances are exchanged from the blood rather than hemodialysis -- which involves fluid removal via the circulatory system.