COLUMBUS, OHIO – The disparity in amputation rates between blacks and non-Hispanic whites in Chicago was higher than the national average and up to five times greater on the predominantly black South Side than on the predominantly white North Side of the city.
The reasons for this disparity are unclear, but a recent study of white and black Chicagoans has shown that the rates at which the races self-report claudication do not differ, suggesting that better utilization of public health resources in the black community could potentially reduce this disparity.
Dr. Samantha Minc
Reporting at the annual meeting of the Midwestern Vascular Surgery Society, lead investigator Samantha Minc, MD, of Rush University in Chicago, said the difference in amputation rates may be traced to later recognition of disease in nonwhites.
“Possible reasons for late recognition of disease include lack of access to care, communication issues with doctors, education issues, or the patient and/or caregiver and primary care provider having difficulty accessing specialists,” Dr. Minc said. “Another often-cited explanation for the late recognition is the possibility of differences in disease symptom manifestations in nonwhites, which is what we chose to study.”
Investigators from Rush University analyzed data from a combined cohort of Chicago residents age 65 years and older from two studies of aging: The Rush Memory and Aging Project and the Minority Aging Research Study.
Because of the segregated nature of Chicago – the North Side is mostly white, the South Side mostly black and the West Side mostly Hispanic – prior research has coupled census data with the Illinois Department of Public Health database to analyze care patterns. This data showed that the disparity in amputation rates among groups in Chicago was higher than the national average and up to five times greater on the South Side, compared with the North, Dr. Minc said.
The latest study matched blacks and whites from both studies 1:2 based on age, education, gender, and length of follow-up. In all, a cohort of 2,487 subjects was generated: 801 blacks and 1,686 non-Hispanic whites. Among blacks, 6.5% reported claudication at baseline, compared with 5.9% of whites, and at any point of the study 19.5% of blacks and 19.6% of non-Hispanic whites reported claudication, differences that were not statistically significant.
Blacks did have higher rates of diabetes, 27% vs. 12.6%, were more likely to have used tobacco, more likely to be female, and were slightly younger on average, but other demographic factors – such as income or rates of congestive heart failure and coronary artery disease – were not significantly different, Dr. Minc said.
The study findings will inform the Chicago Department of Public Health’s Healthy Chicago 2.0 initiative to reduce the disparity in amputation rates between whites and blacks by 10% by 2020.
Dr. Minc acknowledged limitations of the study, among them that participants were volunteers, aged 65 years and older, and 72% female, that Hispanics were excluded, and that the use of the Modified Rose/World Health Organization questionnaire to detect claudication is “specific, but not very sensitive.”
“Our findings suggest that the delay in recognition in disease in nonwhites is not due to a racial differences in disease manifestation or symptomatology and that addressing socioeconomic issues, such as access to care, communication, and education may reduce the racial disparity in amputation rates,” Dr. Minc said. “Public health resources should focus on early recognition of the disease in higher-risk groups to decrease this disparity.”
Dr. Minc and her coauthors had no relationships to disclose.