A study to measure and report racial disparities in ambulatory diabetes care across groups of physicians who treat ambulatory diabetes patients found that a major source of disparities is the low quality of the physician-hospital networks from which Black patients receive care.

The authors used Medicare claims data from 2003-2005 to link patients to their primary ambulatory care physicians and linked patients to the hospital where their physicians worked or had their patients admitted, establishing defined physician-hospital networks. They measured the proportion of recommended diabetes testing that Black and non-Black patients received within each network.

Key Findings:

• Black patients received 70 percent of recommended care, while non-Blacks received 76.9 percent.
• Black patients received less recommended care than non-Blacks in the majority of networks.
• In ambulatory care, Blacks and non-Blacks receive similar care within networks, but 47 percent of Blacks received care from the third of networks with the lowest quality, as compared to 31 percent of non-Blacks.

It is possible to measure and monitor the quality of care that minorities receive at the level of the networks that provide ambulatory care. Addressing disparities should focus on disparities within networks and on improving the performance of lower-quality networks. Limitations of this research include having studied only ambulatory-care patients, examining recommended testing alone rather than in addition to treatment, and using limited race categories.