DURHAM, N.C. — Doctors suggest taking aspirin every day for your heart, but the question is whether it is doing you any good.

Tom Stewart has never had a heart attack. He takes a baby aspirin every day to help make sure he never does.

"I had a couple of risk factors and high cholesterol," he said.

Doctors recommend that people with a history of heart disease take an aspirin daily. People with certain risk factors are often encouraged to do so, but not everyone is following the doctor's orders.

Researchers at Duke claim only 80 percent of patients with heart disease take aspirin regularly. Raising that number to at least 95 percent would save 30,000 lives a year.

Dr. Robert Califf said both doctors and patients share the blame for the lack of compliance.

"The doctor tends not to remind the patient. The patient forgets," he said.

Some patients are also confused over conflicting reports about aspirin. Just this week, one study found that up to 75 percent of patients taking aspirin may be resistant to some of its benefits. Califf said everyone responds differently to aspirin.

"This is really a research finding and we're just beginning to measure aspirin resistance and perhaps change the dosage of that," he said.

There can be some side effects from taking aspirin. The most common side effect is gastrointestinal bleeding, which can happen if you are taking too much aspirin. Most doctors recommend one aspirin or baby aspirin.