Racial, socioeconomic disparities in outcomes ‘systemic,’ not hospital-based

Despite overall advances in healthcare and targeted initiatives to address disparities in care, black patients and those with lower socioeconomic status tend to have worse outcomes for a range of conditions in the U.S. However, based on a recent analysis published in JAMA Network Open, hospital-level differences don’t explain the phenomenon.

“Hospital performance according to race and socioeconomic status was generally consistent within and between hospitals, even as there were overall differences in outcomes by race and neighborhood income,” reported Yale University researchers led by Harlan M. Krumholz, MD, SM. “This finding indicates that disparities are likely to be systemic, rather than localized to particular hospitals.”

Krumholz and colleagues used Medicare claims data to analyze outcomes of patients following hospitalizations for acute myocardial infarction, heart failure and pneumonia between 2009 and 2011. They studied outcomes based on race (black or white) and socioeconomic status to see if any patterns emerged that could explain disparities in 30-day risk standardized mortality rates (RSMRs) or 30-day risk-standardized readmission rates (RSRRs).

Blacks had lower mortality rates than whites for all three conditions, although the difference (of 4.7 percent) was only statistically significant for heart failure. However, the risk of readmissions among black patients was significantly higher for all conditions.

Neighborhood income—based on patients’ zip codes—didn’t have a significant impact on readmission rates for any condition. Likewise, hospitals’ proportions of black patients and patients from lower-income neighborhoods didn’t significantly impact RSMRs or RSRRs, although the researchers noted there was substantial variation between hospitals.

“The minimal difference in risk-standardized mortality and readmission ratios between the race and income groups, and the high (intra-class correlation coefficients), indicate that hospitals that performed better than predicted for one race and neighborhood income subgroup also did so for the other,” the authors wrote. “Black patients and those from lower-income neighborhoods were not disproportionately concentrated in worse-performing hospitals.”

Taken together, the authors believe those findings point to “systemic differences” as contributing to disparate outcomes.

“Consequently, initiatives seeking to address these differences likely will require far-reaching interventions in and out of the healthcare system,” Krumholz et al. noted.

A primary limitation of the study was it excluded almost three-quarters of hospitals nationwide because they lacked sufficient Medicare patients in each racial and neighborhood-income subgroup to make comparisons across those groups. In general, the hospitals that were included in the analysis were more likely to be large, teaching hospitals than those excluded. Also, it is unclear whether the study’s results would translate to younger patients.