Racial disparities in diabetes care processes, outcomes, and treatment intensity

Abstract

Background: Black Americans with diabetes have a higher burden of illness and mortality than do white Americans. However, the extent to which differences in medical care processes and treatment intensity contribute to poorer diabetes outcomes is unknown.

Objective: To assess racial disparities in the quality of diabetes care processes, intermediate outcomes, and treatment intensity.

Methods: We conducted an observational study of 801 white and 115 black patients who completed the Diabetes Quality Improvement Project survey (response rate=72%) in 21 Veterans Affairs (VA) facilities using survey data; medical record information on receipt of diabetes services (A1c, low-density lipoprotein [LDL], nephropathy screen, and foot and dilated eye examinations), and intermediate outcomes (glucose control measured by A1c; cholesterol control measured by LDL; and achieved level of blood pressure); and pharmacy data on filled prescriptions.

Results: There were no racial differences in receipt of an A1c test or foot examination. Blacks were less likely than whites to have LDL checked in the past 2 years (72% vs. 80%, P<0.05) and to have a dilated eye examination (50% vs. 63%, P<0.01). Even after adjusting for patients' age, education, income, insulin use, diabetes self-management, duration, severity, comorbidities, and health services utilization, racial disparities in receipt of an LDL test and eye examination persisted. After taking into account the nested structure of the data using a random intercepts model, blacks remained significantly less likely to have LDL testing than whites who received care within the same facility (68% vs. 83%, P<0.01). In contrast, there were no longer differences in receipt of eye examinations, suggesting that black patients were more likely to be receiving care at facilities with overall lower rates of eye examinations. After adjusting for patient characteristics and facility effects, black patients were substantially more likely than whites to have poor cholesterol control (LDL > or =130) and blood pressure control (BP > or =140/90 mm Hg) (P<0.01). Among those with poor blood pressure and lipid control, blacks received as intensive treatment as whites for these conditions.

Conclusions: We found racial disparities in some diabetes care process and intermediate outcome quality measures, but not in intensity of treatment for those patients with poor control. Disparities in receipt of eye examinations were the result of black patients being more likely to receive care at lower-performing facilities, whereas for other quality measures, racial disparities within facilities were substantial.