Photo by Rhoda Baer
The risk of death from acute myeloid leukemia (AML) may be influenced by where a patient lives, according to a study published in Cancer.
Three regions in North Carolina were found to be associated with a higher risk of death, when compared to the rest of the state.
Patients had a significantly higher risk of death if they lived in northeastern North Carolina (from Wilson to Roanoke Rapids), in a region around Greenville, and a region around Wake County, including Durham County.
The increased risk remained even when the researchers controlled for other factors.
“The geographic survival disparities we found could not be explained by other sociodemographic variables or proximity to experienced treating facilities,” said study author Ashley Freeman, MD, of the University of North Carolina (UNC) in Chapel Hill.
“This raises the possibility that more complex features of the local healthcare infrastructure, including provider referral and practice patterns, are affecting patient outcomes.”
To study death rates from AML across North Carolina, Dr Freeman and her colleagues analyzed data on 553 adults who were diagnosed with AML between 2003 and 2009 and received inpatient chemotherapy within 30 days of diagnosis.
The team used the UNC Lineberger Integrated Cancer Information and Surveillance System, a database that links insurance claims information to a state information database called the NC Cancer Registry.
The researchers assessed the risk of death in 9 regions defined by the North Carolina Area Health Education Centers (AHEC) Program, a program established in 1972 to address physician shortages and the uneven distribution of healthcare services in North Carolina.
“We looked at geographic disparities because we are trying to improve outcomes for all citizens in North Carolina, consistent with the mission of our cancer center,” said William A. Wood, MD, of UNC.
“We are also trying to find situations in which disparities shouldn’t exist but do for arbitrary reasons—such as where a patient happens to live—so that we can figure out how to improve equity across the state.”
The researchers determined that a region around Greensboro had the lowest risk of death for AML.
Compared to the Greensboro region, the risk of death was 4 times higher in an area of northeastern North Carolina that included Roanoke Rapids, Rocky Mount, and Wilson—the highest in the state.
Compared to the Greensboro region, the risk of death was more than 2 times greater in the eastern region of the state around Greenville, and it was nearly twice as high in the region around Wake County.
“There are areas of the state where there is an elevated mortality, and we need to better understand the factors that are driving that—whether they’re environmental, patient, or provider-related,” said Anne-Marie Meyer, PhD, of UNC.
Nearly half of patients in the study received their care at hospitals not affiliated with one of the state’s 3 National Cancer Institute (NCI) comprehensive cancer centers.
The researchers did not find a significant link between the risk of death and the distance from patients’ homes to their treating facility or the nearest NCI-designated center.
And there was no significant difference in the risk of death at 1 year between patients who received treatment at an NCI-designated cancer center and those who did not. However, patients with a more serious prognosis were more likely to be treated at an NCI-designated cancer center.
The researchers did identify regional differences in healthcare resources. “Area L,” which is the name for the region in northeastern North Carolina that spans from Wilson to Roanoke Rapids, for example, has some of the lowest proportion of general practitioner physicians and radiation oncologists, as well as the highest burden of disease.
However, it is not clear why the disparities continued even after the researchers controlled for regional factors like poverty and education. The team believes other factors could be involved, such as the providers’ experience with treating rare or complex diseases or how supportive care is delivered.
Although there was not a significant association between survival and treatment at an NCI-designated center, there may be other features of treatment facilities, such as patient volume and academic affiliation, that are important for patient outcomes.
The researchers said their next step is to identify those factors and develop programs to try to close the gaps.
“The message here is that acute myeloid leukemia is representative of diseases that are uncommon, involve high-complexity care, and have high risk for morbidity and mortality,” Dr Wood said.
“If we can figure out how to coordinate and improve delivery of effective interventions for this disease throughout the state of North Carolina, then we may be able to develop a model for improving outcomes in many other diseases throughout the state as well.”
