Nationally there are 17,000 people on the waiting list for a liver transplant. Yet according to A. Sidney Barritt, IV, M.D., M.S.C.R., surgeons are able to perform only about 6,000 transplants annually. And, unfortunately, the obesity and diabetes epidemics in this country may be reducing the number of viable organs for transplantation each year. Thus, science which advances the understanding of how best to treat patients and prevent mortality while they wait for transplants is vital.
Barritt and colleagues from UNC-Chapel Hill funded, in part, by an NIH KL2 grant through the North Carolina Translational and Clinical Sciences (NC TraCS) Institute studied one of the factors that may affect mortality of patients awaiting transplant – the density of gastroenterology (GI) specialists in their home communities. He presented his findings at the annual Liver Meeting of the American Association of the Study of Liver Disease and received an AASLD Presidential Poster of Distinction award in November.
Previous studies have looked at patients’ geographic distance from the transplant center, hypothesizing that the greater the distance, the lower the transplant rate. Instead, Barritt and his team considered the density of GI subspecialists in communities and found a correlation: the more GI subspecialists patients have in their home communities, regardless of how far they lived from the transplant center, the better the outcome.
This study showed that among patients referred for liver transplant, the number of gastroenterologists in their home hospital service area independently increases the odds of receiving a liver transplant by 16% for each additional gastroenterologist per 100,000 population. Increasing Model for End-stage Liver Disease (MELD) score and hepatocellular carcinoma also increase the odds of receiving a transplant. Medicaid and Medicare insurance coverage are detrimental to a patient’s odds of receiving a liver transplant, but are better than no insurance coverage at all.
“We were not looking at referral patterns. We were not looking at whether a gastroenterologist was more likely to send you to UNC,” said Barritt. “We were looking at whether the number of gastroenterologists in a community helps keep you alive and a viable transplant candidate from referral to ultimately getting a transplant.”
“Access to local subspecialty care improved the odds of transplant for our patient population most likely because we are a centrally located tertiary care transplant center and many of our patients continue to receive medical care locally. Access to local experts is a great boon to our center in co-managing these patients and we rely heavily on their expertise to get chronically and often critically ill patients through to liver transplant. As our referral base measures more than 500 miles in diameter, we are unable to follow some of our patients on a weekly basis. Additionally, when our medical center has no available beds for inpatient transfers, our colleagues around the state help facilitate patient care locally,” said Barritt.
The project also tested a clinical transplant database at UNC to see whether it is valid for use as a research database. The investigators hope that in the future they can combine these data with that of certain other transplant centers so they can conduct studies with more generalizable findings than research currently available from large single-center studies or from the United Network of Organ Sharing database, which lacks some patient specific data.
Barritt is an assistant professor in the Department of Medicine, Division of Gastroenterology and Hepatology, UNC School of Medicine. He is also a KL2 Scholar, in the second year of three years of support by NC TraCS. The KL2 program objective is to train and develop junior investigators who will become the next generation of successful translational researchers. It does this by providing classroom and experiential training, mentoring, funding for research and, perhaps most importantly, protected research time.
His colleagues on the project are: Stephen A. Telloni, M.D., Department of Medicine; Clarence W. Potter, M.S., NC TraCS; David A. Gerber, M.D., associate professor, Department of Surgery, Division of Abdominal Transplant; and Paul H. Hayashi, M.D., M.P.H., assistant professor and medical director of liver transplantation.