Background and aims: Acetyl-salicylic acid use is recommended for primary prevention of atherosclerotic vascular disease (ASCVD) for people with and without diabetes when the ASCVD benefit out- weighs the risk of gastrointestinal hemorrhage. In a primary care setting, the complexity and time required to assess acetyl-salicylic acid benefits and risks can result in inappropriate acetyl-salicylic acid use either through overuse or underuse. The objective of this analysis is to assess the appropriateness of acetyl-salicylic acid use for primary prevention in diabetes and other high ASCVD risk patients in a
large primary care setting with good electronic health record acetyl-salicylic acid documentation. Materials and methods: As part of an NIH-funded study to lower ASCVD risk, we successfully implemented electronic clinical decision support (CDS) algorithms to encourage appropriate acetyl-salicylic acid use. The algorithms recommended acetyl-salicylic acid if ASCVD risk scores were high and consistent with benefit greater than GI bleed risk using criteria from the United States Preventive Services Task Force; and acetyl-salicylic acid was not recommended if the ASCVD benefit was low or if major contraindications were identified (anticoagulant use or history of intracerebral hemorrhage). Providers were also alerted to the presence of other potential acetyl-salicylic acid risks including acetyl-salicylic acid allergy or intolerance, history of GI bleed risk conditions, and concomitant use of nonsteroidal antiflammatory drugs. Baseline study data was collected for whether acetyl-salicylic acid was algorithmically recommended for all patients at their first eligible primary care encounter in 20 clinics over 2012-2014. The analysis excluded patients with CHD and included 6065 adults with diabetes (mean age 55.6, mean 10-year ASCVD risk 27.9%) and 10,165 adults meeting pre-specified criteria foor high ASCVD risk without diabetes (mean age 58.4, mean 10-year ASCVD risk 24.6%). Overuse and underuse was determined by comparing concordance with (a) acetyl-salicylic acid algorithm recommendations and (b) documented acetyl-salicylic acid use. Results: For the targeted population with high CV risk, the CDS recommended acetyl-salicylic acid for 3,842 (63.3%) patients with diabetes and 7,552 (74.3%) without diabetes. Among patients with acetyl-salicylic acid recommended, acetyl-salicylic acid was underused in 761(19.8%) with diabetes and 5638 (74.4%) without diabetes. Among patients for whom the CDS did not recommend acetyl-salicylic acid, acetyl-salicylic acid was overused in 1322 (59.5%) with diabetes and 883 (33.8%) without diabetes. Conclusion: In this large primary care setting, acetyl-salicylic acid was more likely to be overused than underused for patients with diabetes. Those with diabetes who were likely to benefit from acetyl-salicylic acid use had higher acetyl-salicylic acid use rates than similar high CV risk patients without diabetes. However, those with diabetes who were unlikely to benefit from acetyl-salicylic acid (risks greater than benefit) also had higher rates of acetyl-salicylic acid overuse compared to patients without diabetes. Strategies to ensure greater evidence-based use of acetyl-salicylic acid, such as providing electronic clinical decision support, may help providers more accurately assess individualized risks and benefits of acetyl-salicylic acid.