Diabetes is a disease in which the body cannot properly use and store glucose. It is a life-long condition that requires continuous management. Diabetes can lead to many complications, including heart attacks, strokes, blindness, kidney failure, nerve damage, poor circulation, and loss of limbs. Adults with diabetes often have other conditions, such as high blood pressure or abnormal lipid levels, that also increase risks for complications. Thus, properly managed diabetes often requires several things. These include blood tests; eye and foot checks; medications to control glucose levels, lipid levels, and blood pressure; and counseling about diet, weight, exercise, and aspirin use to help prevent heart attacks. Few studies compare how well different health care systems deliver these components of diabetes care.