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Racial Disparities in Diabetes Care Processes, Outcomes, and Treatment Intensity

Heisler, Michele MD, MPA*†‡§; Smith, Dylan M. PhD*‡; Hayward, Rodney A. MD*†‡§; Krein, Sarah L. PhD, RN*‡§; Kerr, Eve A. MD, MPH*†‡§

Original Articles

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 ≥130) and blood pressure control (BP ≥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.

Type 2 diabetes is one of the most prevalent and fastest growing chronic diseases in the United States. 1 Black Americans, Latinos, and Native Americans experience a 50% to 100% higher burden of illness and mortality as a result of diabetes than white Americans. 2 Black and Hispanic Americans have disproportionately high rates of end-stage renal disease (ESRD), retinopathy and blindness, neuropathy, and nontraumatic lower-extremity amputations. 3–6

Inadequate access to medical care contributes to higher rates of adverse health outcomes among some ethnic minorities in the United States. 2,7 Moreover, black and other minority patients often receive worse technical health care than white Americans. 2,8–11 Whether and how differences in medical care contribute to worse clinical outcomes in minority groups with diabetes, however, is less understood. Evidence is mixed on whether there are racial differences in diabetes processes of care. 3,12–14 In addition, although nationwide black patients with diabetes have worse glycemic and blood pressure control than other groups, 1,3,15 studies have not assessed whether these patients receive less aggressive treatment for these conditions.

To assess the contribution of disparities in medical care to differential clinical outcomes, we need to determine if there are racial differences in the quality-of-care processes that can directly influence outcomes. Previous studies on disparities in diabetes care have not included information on care processes and clinical outcomes in the same study. They have also lacked data on patient characteristics that could influence both diabetes care and outcomes such as diabetes severity and self-management, and on the facilities in which patients receive care. 16–18 Accordingly, it has not been possible to assess the relative contribution of patient, provider, and healthcare facility factors, and the interactions among these, toward explaining variations in diabetes care and outcomes.

To address these gaps in knowledge, we asked the following research questions in a sample of patients with diabetes receiving care at 1 of 25 facilities in the Department of Veterans Affairs Health Care System (VA): 1) Are there racial disparities in the receipt of diabetes services and in intermediate outcomes? 2) If so, how do patient characteristics influence differences? 3) Are racial disparities the result of patients receiving care at different facilities or differential receipt of care within facilities? 4) Do differences in treatment intensity contribute to any observed variations in outcomes?

From the *Veterans Affairs Center for Practice Management & Outcomes Research, VA Ann Arbor Healthcare System, Ann Arbor, Michigan.

From †The Robert Wood Johnson Clinical Scholars Program,

‡Department of Internal Medicine,

and §Michigan Diabetes Research and Training Center, University of Michigan School of Medicine, Ann Arbor, Michigan.

Address correspondence and reprint requests to: Michele Heisler, MD, MPA, HSR&D Field Program, P.O. Box 130170, Ann Arbor, MI 48113-0170. E-mail:

© 2003 Lippincott Williams & Wilkins, Inc.