Because of the scope of the problem of cardiovascular disease (CVD) in patients with diabetes and the conflicting evidence about the efficacy of aspirin for primary prevention in this group, the American Diabetes Association (ADA), the American Heart Association (AHA) and the American College of Cardiology Foundation (ACCF) convened a group to review and synthesise the available evidence and use this information to create updated recommendations. The following questions were addressed:

1. What is the evidence regarding aspirin to prevent initial cardiovascular events in people with diabetes?

2. How can we reconcile the results of the different primary prevention trials?

3. What are the risks of aspirin, and are these similar or different for people with diabetes compared to those without?

4. What do we know about the recommended dosage or dosage range?

5. How can we integrate potential benefits and risks of aspirin to determine which patients with diabetes should receive aspirin for the primary prevention of cardiovascular events?

6. What are the needs for future research?

Overall, the group concluded that the effect of aspirin for primary prevention of CVD events in adults with diabetes is currently unclear as trials to date have reached mixed results, but overall suggest that aspirin modestly reduces risk of cardiovascular events. For now, the following: recommendations have been issued:

• Low-dose (75–162 mg/day) aspirin use for prevention is reasonable for adults with diabetes and no previous history of vascular disease who are at increased CVD risk (10 year risk CVD events >10%) and who are not at increased risk for bleeding. Those adults with diabetes at increased CVD risk include most men over age 50 years and women over age 60 years, who have one or more of the following additional major risk factors: smoking, hypertension, dyslipidaemia, family history of premature CVD, and albuminuria.

• Aspirin should not be recommended for CVD prevention for adults with diabetes at low CVD risk (men under age 50 years and women under 60 years with no major additional CVD risk factors; 10-year CVD risk < 5%) as the potential adverse effects from bleeding offset the potential benefits.

• Low-dose (75–162 mg/day) aspirin use for prevention might be considered for those with diabetes at intermediate CVD risk (younger patients with one or more risk factors, or older patients with no risk factors, or patients with 10-year CVD risk of 5–10%) until further research is available.