1. Aspirin use resulted in a 12% lower risk of serious vascular events but also a 29% higher risk of major bleeding in patients with diabetes but no cardiovascular disease. The benefits of aspirin for vascular events were similar to the risks of major bleeding.
2. There was no significant effect of aspirin on cancer risk or microvascular outcomes. No differences emerged even with long-term follow-up.
3. The risks and benefits of low-dose aspirin were closely balanced in patients with diabetes but no cardiovascular disease. Routine aspirin use cannot be recommended for primary prevention in this population.