Trends in Ambulatory Prescribing of Antiplatelet Therapy among US Ischemic Stroke Patients: 2000–2007

Sudeep Karve,Milap Nahata,Rajesh Balkrishnan,Eric Seiber,Deborah Levine

doi:10.1155/2012/846163

Abstract

Objective. Study objectives were to assess temporal trends and identify patient- and practice-level predictors of the prescription of antiplatelet medications in a national sample of ischemic stroke (IS) patients seeking ambulatory care. Methods. IS-related outpatient visits by adults were identified using the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey for the years 2000–2007. We assessed prescribing of antiplatelet medications using the generic drug code and drug entry codes in these data. Temporal trends in antiplatelet prescribing were assessed using the Cochran-Mantel-Haenszel test for trend. Results. We identified 9.5 million IS-related ambulatory visits. Antiplatelet medications were prescribed at 35.5% of visits. Physician office prescribing of the clopidogrel-aspirin combination increased significantly from 0.5% in 2000 to 22.0% in 2007 (P = 0.05), whereas prescribing of aspirin decreased from 17.9% to 7.0% (P = 0.50) during the same period. Conclusion. We observed a continued increase in prescription of the aspirin-clopidogrel combination from 2000 to 2007. Clinical trial evidence suggests that the aspirin-clopidogrel combination does not provide any additional benefit compared with clopidogrel alone; however, our study findings indicate that even with lack of adequate clinical evidence physician prescribing of this combination has increased in real-world community settings.

Highlights

In 2008, approximately 7 million individuals were reported to have a history of stroke [1]
Clinical trial evidence suggests that the aspirin-clopidogrel combination does not provide any additional benefit compared with clopidogrel alone; our study findings indicate that even with lack of adequate clinical evidence physician prescribing of this combination has increased in real-world community settings
We identified all patients age 18 years or older who had an ambulatory visit with a primary physician diagnosis of ischemic stroke (IS) using valid ICD9-CM codes (433.x1, 434.xx, 436.xx) [23,24,25,26] and recorded in the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) data from January 2000 through December 2007

Summary

Introduction

In 2008, approximately 7 million individuals were reported to have a history of stroke [1]. To reduce the recurrence of ischemic stroke (IS), the major stroke type accounting for 85% of strokes, modification of vascular risk factors [2,3,4], and antithrombotic therapy are recommended for stroke survivors [5, 6]. Antithrombotic therapy may include vitamin K antagonist therapy if atrial fibrillation is present (cardioembolic strokes) or antiplatelet therapy (noncardioembolic strokes). Antiplatelet therapy can reduce the relative risk of IS by approximately 15% [7]. Clinicians have uncertainty regarding the selection of antiplatelet therapy for secondary stroke prevention among patients with noncardioembolic IS [8,9,10,11,12,13,14,15,16,17]

Methods

Results

Conclusion