Aspirin: Interpreting Changes in RecommendationsPosted August 3, 2011 by Kevin A. Peterson, MD, MPH
It was only 2007 that the American Diabetes Association and the American Heart Association recommended together that almost everyone with diabetes over 40 years old should take aspirin. Clinical performance groups picked up the recommendation, and we soon began to see the emergence of “pay for performance programs” that added aspirin to their measure of optimal diabetes care and reimbursed providers accordingly.
Now those recommendations have changed. Last year the ADA, AHA, and ACC issued joint recommendations urging caution in the use of acetylsalicylic acid (ASA) for primary prevention of CVD. Their new recommendation is only to encourage low dose ASA for adults with diabetes that have a 10-year risk of cardiovascular disease of over 10%. This includes most men over 50 and women over 60 with one additional major risk factor (smoking, hypertension, dyslipidemia, family history, or albuminuria). People with diabetes that have less than a 5% risk of CVD over 10 years, however, should not take ASA, since the risk of gastrointestinal bleeding or hemorrhagic stroke is probably greater than the potential benefit. People with an intermediate risk (5-10% over 10 years) should consider ASA and discuss it with their doctor. Since the FDA does not approve ASA for primary prevention of CVD, insurance is not likely to pay for it.
How Did We Get Here?
Metaanalysis provided by the Antithrombotic Trialists’ (ATT) study clearly demonstrated that ASA reduced cardiovascular morbidity and mortality in high-risk patients for MI or stroke. However, with the publication of the Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes (JPAD) study and the Prevention of Progression of Arterial Disease and Diabetes (POPADAD)studies, better data are available about ASA and the primary prevention of cardiovascular disease. It is not such a surprise that in individuals at low risk, ASA doesn’t help prevent cardiovascular disease.
The findings for diabetes patients suddenly look a lot like the recommendation of the United States Preventive Services Task Force (USPSTF) concerning aspirin use by people without diabetes. The USPSTF encourages the use of ASA in men age 45-79, and women 55-79 (Evidence A-good evidence for) if the risk outweighs benefit, but recommends against ASA use at younger ages (Evidence D -good evidence against). Deciding if risk outweighs benefit means putting everyone into a risk calculator that estimates 10-year risk of CVD adjusted for age and sex, and comparing that to the age-adjusted risk of gastrointestinal bleeding and hemorrhagic stroke to determine whether aspirin use is right for the individual.
Putting the New Recommendations Into Practice
So where do the new recommendations fit into the clinical work flow? With an average face-to-face time of 12 minutes, every second is important, and these recommendations just added a few minutes to the average visit workload. We haven’t looked at what the effect of further diminishing patient-physician interaction time will do to overall health care. Of course, our electronic health record (EHR) should do this, but I don’t know of any EHR that actually does. So now we have more software to buy.
We also need to ensure that high quality health care delivery is based on evidence, not payment reform. To do so, aspirin should be recommended based on the comparative risks of a CV event versus a GI bleed. Since A1c metrics have changed, A1c targets should also be tailored to individual risks and benefits. Blind adherence to standardized targets can cause the best treatment for the individual to get lost.
The best diabetes care for the individual has always required an individual guideline. As recommendations continue to evolve, I am reminded that algorithms and target metrics are crude measures of population health, and that the highest quality of diabetes care is best delivered one person at a time.
1. Baigent C, et al. Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials. Lancet. 2009 May 30;373(9678):1849-60.
2. Ogawa, H., et al., Low-dose aspirin for primary prevention of atherosclerotic events in patients with type 2 diabetes: a randomized controlled trial. JAMA. 2008 Nov 12;300(18):2134-41. Epub 2008 Nov 9
3. Belch J., et al. The prevention of progression of arterial disease and diabetes (POPADAD) trial: factorial randomised placebo controlled trial of aspirin and antioxidants in patients with diabetes and asymptomatic peripheral arterial disease. BMJ. 2008 Oct 16;337:a1840.