This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Johnson, S. G. Search for Related Content PubMed PubMed Citation Articles by Johnson, S. G.

Warfarin and Antiplatelet Combination Use Among Commercially Insured Patients Enrolled in an Anticoagulation Management Service^*

^* From the Clinical Pharmacy Anticoagulation Service (Drs. Johnson, Witt, and Eddy) and Clinical Pharmacy Research Team (Dr. Delate), Kaiser Permanente Colorado, Aurora, CO.

Correspondence to: Samuel G. Johnson, PharmD, BCPS, Kaiser Permanente of Colorado, 16601 E Centretech Pkwy, Aurora, CO 80011; e-mail: samuel.g.johnson{at}kp.org

Abstract

Background: Although warfarin and antiplatelet medications have documented efficacy for prevention of primary and secondary cardiovascular events, the appropriateness of warfarin and antiplatelet combination therapy is not well described in national consensus guidelines.

Methods and results: Cross-sectional data from 4,557 Kaiser Permanente Colorado members 18 years old who were receiving warfarin anticoagulation therapy were used to quantify the prevalence of warfarin and antiplatelet agent (ie, aspirin, clopidogrel, dipyridamole, and/or dipyridamole/aspirin) combination therapy as of September 30, 2005, and to identify characteristics of patients receiving combination therapy. The prevalence of warfarin and any antiplatelet combination therapy was 385/1,000 (95% confidence interval [CI], 371/1,000 to 399/1,000). The majority of combination therapy was warfarin and aspirin (prevalence, 378/1,000) with a daily dose of aspirin, 81 mg, being the most reported dose (prevalence, 328/1,000). Patients receiving combination therapy were more likely to be male (63.6% vs 46.4%; adjusted odds ratio, 1.5; 95% CI, 1.3 to 1.7) and have a comorbidity of heart failure (29.0% vs 15.6%; adjusted odds ratio, 1.2; 95% CI, 1.1 to 1.5), coronary artery disease (62.4% vs 17.5%; adjusted odds ratio, 7.6; 95% CI, 6.5 to 8.8), and/or stroke/transient ischemic attack (5.2% vs 1.6%; adjusted odds ratio, 3.5; 95% CI, 2.3 to 5.3).

Conclusion: Nearly 4 of 10 patients receiving warfarin management care were receiving warfarin and antiplatelet combination therapy. The findings suggest that this practice is widespread, especially among patients with established cardiovascular disease, and involves a substantially higher number of patients than previously reported. The clinical outcomes associated with this practice require further investigation.

Key Words: anticoagulation • aspirin • pharmacy

This article has been cited by other articles:

				S. G. Johnson, K. Rogers, T. Delate, and D. M. Witt Outcomes Associated With Combined Antiplatelet and Anticoagulant Therapy Chest, April 1, 2008; 133(4): 948 - 954. [Abstract] [Full Text] [PDF]