Disparities in cancer care reflect hospital resources, U-M study finds
Hospital quality among factors leading to survival differences|
August 20, 2009
"After risk adjustment, hospital factors explained 36% and 54% of the excess mortality for black patients with breast cancer and colon cancer, respectively. Hospitals with large minority populations had higher late mortality rates independent of race....Hospital-level quality improvement should be a major component of efforts to reduce disparities in cancer outcomes."
ANN ARBOR, Mich. - Hospitals that treat more black cancer patients have worse survival rates on average for patients with breast and colon cancer, regardless of race, according to a new study from the University of Michigan Comprehensive Cancer Center.
The research helps explain why African-Americans with breast or colon cancer are less likely than white patients to survive the disease.
"This work highlights the importance of how where a patient receives treatment for cancer affects survival after cancer surgery. An important next step will be to determine which system factors are amenable to interventions aimed at improving the quality of cancer care," says study author Tara M. Breslin, M.D., assistant professor of surgery at the U-M Medical School.
The study used five year survival data from the Surveillance Epidemiology and End Results-Medicare-linked database, a federal collection of cancer incidence, survival, and prevalence. The researchers analyzed data from 25,571 breast cancer patients, 9.7 percent of whom were black, and 22,168 colon cancer patients, 11.8 percent of whom were black. The patients were treated in 436 hospitals.
The study appears in the Aug. 20 issue of the Journal of Clinical Oncology.
Survival rates were lower for black patients than for white patients with both breast and colon cancer. But hospitals where more than half the patients were black had an increased risk of dying after five years for both black and white patients, compared to hospitals where fewer than 10 percent of patients were black.
All breast cancer patients treated at predominantly black hospitals had a 32 percent increased risk of death after five years, compared with those treated at hospitals that see few black patients. Similarly, colon cancer patients had a 27 percent higher risk of dying at five years.
The researchers also examined patient factors, such as age, cancer stage, other medical conditions and socioeconomic status. They found that after accounting for these factors, black patients still had higher mortality rates.
"Efforts aimed at increasing early detection through screening and decreasing incidence with preventative services are essential for decreasing racial disparities in mortality, but where a patient receives care after a cancer diagnosis may be equally important," says senior study author Arden M. Morris, M.D., M.P.H., assistant professor of surgery at the U-M Medical School and chief of general surgery at the VA Ann Arbor Healthcare System.
The study did not identify what specific hospital factors were at play, but the researchers plan further analyses to determine which hospital systems and aspects of standard therapy are poorly delivered or absent in hospitals serving a high percentage of minority patients.
Cancer statistics: 194,280 Americans will be diagnosed with breast cancer this year, and 106,100 will be diagnosed with colon cancer, according to the American Cancer Society.
Additional authors: Niya Gu, Sandra L. Wong, Emily V. Finlayson, Mousumi Banerjee and John D. Birkmeyer, all from U-M
Funding: National Cancer Institute
Reference: Journal of Clinical Oncology, Vol. 27, No. 24, pp. 3945-3950
Hospital Might Explain Cancer Outcome Disparities
By Todd Neale, Staff Writer, MedPage Today
August 21, 2009
* Explain to interested patients that this study did not identify the specific hospital factors that contributed to worse survival among black patients diagnosed with breast and colon cancer.
The nature of the hospitals that treat them might help explain why blacks fare worse than whites after a cancer diagnosis, researchers found.
After adjusting for patient and other factors, the effects of individual hospitals accounted for 36% of the excess mortality from breast cancer and 53.8% of the excess mortality from colon cancer among black patients, according to Tara Breslin, MD, of the University of Michigan in Ann Arbor, and colleagues.
Further studies will be needed to identify the specific system factors contributing to the disparate outcomes, they wrote in the Aug. 20 issue of the Journal of Clinical Oncology.
Breslin and her colleagues used data from the Surveillance Epidemiology and End Results-Medicare linked database to identify patients who underwent surgery after receiving a diagnosis of breast or colon cancer at 436 hospitals.
They included 25,571 patients with breast cancer (of whom 9.7% were black) and 22,168 patients with colon cancer (11.8% were black).
As expected, five-year survival rates were significantly lower among blacks -- 62.1% versus 70.4% among whites for breast cancer and 41.3% versus 45.4% for colon cancer (P<0.001 for both).
The disparity remained after adjusting for age, cancer stage, and socioeconomic status.
The analysis also disclosed that hospitals with predominantly black patient populations had significantly worse five-year survival rates for both white and black patients diagnosed with breast (HR 1.32, 95% CI 1.20 to 1.45) and colon cancer (HR 1.27, 95% CI 1.18 to 1.37) than hospitals in which less than 10% of the patients were black.
"Our study is not the first to demonstrate the importance of system factors in explaining racial disparities in outcomes with specific conditions or procedures," the researchers said.
They cited other studies showing that blacks had lower referral rates to high-volume centers, less access to high-quality surgeons, greater chances of experiencing treatment delays, and worse chances of receiving adjuvant therapy.
Although Breslin and her colleagues could not identify the specific hospital factors associated with worse survival, they said it might have to do with reduced access to high-quality staff and technology, or differences in how resources are allocated in hospitals treating more disadvantaged patients.
The study was limited, they said, by being limited to Medicare patients over 65.
"Racial disparities in late survival after cancer care may be even more pronounced in the large proportion of minority patients without insurance," they said.
Additional limitations included the reliance on administrative data to identify comorbidities, which may have underestimated their contribution to overall mortality; the lack of patient-level measures of income, education, and other socioeconomic variables; limited statistical power for examining hospital subgroups, and the focus on blacks and whites only.
Primary source: Journal of Clinical Oncology
Breslin T, et al "Hospital factors and racial disparities in mortality after surgery for breast and colon cancer" J Clin Oncol 2009; 27: 3945-50.