Evaluation of the Appropriateness of Aspirin Therapy in a Veteran Population
Background: Aspirin is commonly used for primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD) but may cause more harm than benefit. This study aimed to assess the percentage of patients who were inappropriately prescribed aspirin in the veteran patient population and to assess safety outcomes associated with inappropriate aspirin use.
Methods: Retrospective chart reviews were conducted on up to 200 patients with active prescriptions for 81-mg aspirin tablets filled between October 1, 2019, and September 30, 2021, at the Captain James A. Lovell Federal Health Care Center in Illinois. The primary endpoint was the percentage of patients inappropriately on aspirin therapy and whether these patients were being followed by a clinical pharmacy practitioner. Each patient record was reviewed to determine the appropriateness of aspirin therapy by assessing the indication for use. Safety data were collected for patients who were deemed to be using aspirin inappropriately, including documentation of any major or minor bleeding events.
Results: A total of 105 patients were included in this study. For the primary endpoint, 31 patients (30%) had a possible ASCVD risk and were taking aspirin for primary prevention, while 21 patients (20%) had no ASCVD and were taking aspirin for primary prevention. For the secondary endpoint, 25 patients were aged > 70 years, 15 patients were concurrently taking medications that might increase bleeding risk, and 11 patients had chronic kidney disease. Looking at the entire study patient population, for the safety endpoint, 6 patients (6%) experienced a major bleeding event while on aspirin, and 46 (44%) experienced a minor bleeding event while on aspirin.
Conclusions: Common factors seen in this study to warrant deprescribing aspirin for primary prevention included individuals aged > 70 years, concurrent use of medications that increase bleeding risk, and patients with chronic kidney disease. By assessing ASCVD and bleeding risks and having a risk/benefit discussion with patients and prescribers, aspirin used for primary prevention can be appropriately deprescribed when the risks of bleeding outweigh the benefits.
Strengths and Limitations
As there have been recent updates to guidelines on the use of aspirin for primary prevention, a strength of this study is that it evaluates a topic that is relevant in health care. Another strength of this study is that it focuses on specific patient factors that HCPs can assess when determining whether aspirin for primary prevention is appropriate in their patients. These specific patient factors can also be used as a guide to help HCPs deprescribe aspirin for primary prevention when appropriate.
One of the limitations of this study is that bleeding events that occurred outside of the FHCC were unable to be assessed unless the HCP specifically commented on the bleeding event in the chart. This could potentially underestimate the bleeding events seen in this study. Another limitation is that the bleeding risk for patients who were not on aspirin was not assessed. There was no comparison group to ascertain whether the bleeding risk was higher in the aspirin group compared with a no aspirin group. However, many of the major clinical trials saw an increased risk of bleeding in the aspirin group compared with placebo.
Conclusions
Aspirin therapy for secondary prevention remains an important part of treatment. Aspirin therapy for primary prevention may be appropriate for patients with a possible ASCVD risk. The therapy may be inappropriate in cases where patients have an increased bleeding risk and low or no ASCVD risk. It is important to continuously assess the need for aspirin therapy for patients in the setting of primary prevention. Common factors seen in this study to warrant deprescribing aspirin for primary prevention include patients aged > 70 years, concurrent use of medications that increase bleeding risk, and patients with CKD. By assessing ASCVD risk as well as bleeding risk and having a risk/benefit discussion between the HCP and patient, aspirin used for primary prevention can be appropriately deprescribed when the risks of bleeding outweigh the benefits.
Acknowledgments
The authors thank the Captain James A. Lovell Federal Health Care Center research committee (Hong-Yen Vi, PharmD, BCPS; Shaiza Khan, PharmD, BCPS; Yinka Alaka, BPharm, PharmD; Jennifer Kwon, PharmD, BCOP) and coinvestigator Aeman Choudhury, PharmD, BCPS, BCACP.
