Black Medicare patients have higher 30-day readmission rates for three common medical conditions than do their white counterparts, but this discrepancy has more to do with the sites where patients receive care than with race itself, according to a report in the Feb. 16 issue of JAMA.
"We found that the association of readmission rates with the site of care was consistently greater than the association with race, suggesting that racial disparities in readmissions are, at least in part, a systems problem," said Dr. Karen E. Joynt of Harvard School of Public Health, Boston, and her associates.
In what they described as the first study to examine racial disparities in readmission rates at the national level, the investigators used Medicare records to assess 30-day readmissions after acute myocardial infarction, congestive heart failure, or pneumonia during a 3-year period. The sample included 3,163,011 discharges: 579,492 discharges for acute MI from 4,322 hospitals, 1,346,768 discharges for CHF from 4,560 hospitals, and 1,236,751 discharges for pneumonia from 4,588 hospitals.
A total of 8.7% of patients were black.
Approximately 40% of black patients and 6% of white patients were cared for at hospitals designated as primarily "minority serving." These centers were more likely to be large public hospitals, to be located in the South, to have a high proportion of Medicaid patients, to have fewer nurses per patient days, and to have "somewhat lower performance" on measures of health care quality than other hospitals.
Overall, black patients had a 13% higher rate of readmission for any cause than white patients.
However, patients discharged from minority-serving hospitals had a 23% higher rate of readmission than did those discharged from non–minority-serving hospitals, and readmission rates were higher for white patients who were treated at minority-serving hospitals than they were for black patients treated at non–minority-serving hospitals. These findings show that the site of hospitalization had a greater effect on readmission rates than did race per se.
When readmissions for the same cause as initial hospitalization were considered, the same pattern was found. Black MI patients and black CHF patients both had 13% higher rates of readmission than did white MI patients with those diagnoses. However, patients discharged from minority-serving hospitals had much higher rates of readmission for those diagnoses than did patients discharged from non–minority-serving hospitals.
This pattern persisted when the data were adjusted to account for hospital characteristics such as teaching status, size, and ownership. It also did not change when data on Hispanic, Asian-American, and other nonwhite, nonblack ethnic groups were excluded.
It is important to note that "factors beyond hospitals’ control may explain our findings," Dr. Joynt and her colleagues said.
These include the quality of early outpatient follow-up and disease management after the initial hospitalization. "It may be that the availability of high-quality outpatient care is limited for patients discharged from minority-serving hospitals; these issues should be better understood before hospitals are held solely accountable for high readmission rates," they stressed (JAMA 2011;305:675-81).
The researchers added that their study did not include data on specific medications and treatment procedures, so discrepancies in these important factors between black and white patients could not be addressed. Similarly, their sample included only older patients, so it is not clear whether the findings apply to younger patients or those with other medical conditions.
This study was supported in part by the National Institutes of Health. One coauthor reported financial ties to UpToDate Inc.