Physicians' actions and influence, such as aggressive blood pressure control, greatly improve the health of diabetes patients.

Managing diabetes and preventing its associated morbidities require active partnerships between physicians and patients. Studies to date lack the level of detail to quantify the degree to which interventions that are more controlled by physicians influence outcomes versus those that are more controlled by patients. Using the Archimedes model, we simulated a thirty-year clinical trial and compared the effects of three sets of interventions over which physicians have progressively less control: compliance with process-of-care standards, such as conducting foot and retinal exams and screening for signs of early kidney disease; control of biomarkers, such as hemoglobin A1c and blood pressure; and lifestyle modifications, such as patients' switching to healthier diets and losing weight. We found that if all US adults diagnosed with type 2 diabetes met quality targets in all of these areas, they would experience a nearly 16 percent increase in quality-adjusted life-years and a nearly 23 percent reduction in fifteen-year mortality over the thirty-year simulation period. Meeting aggressive biomarker targets yielded the most benefit. Meeting conservative biomarker targets came next, followed closely by meeting process-of-care standards. The incremental benefits of complying fully with diet and smoking cessation yielded the least benefit. Thus, through measures more readily within their control, and through collaboration with their patients, physicians have a substantial opportunity to improve outcomes. These findings can inform policy makers' rational resource allocation decisions and the design of programs to improve diabetes care.