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Community-Based Control and Persistence of Warfarin Therapy and Associated Rates and Predictors of Adverse Clinical Events in Atrial Fibrillation and Venous Thromboebolism (WAVE) Study

Atria Project


Alan S. Go, MD, Prinicpal Investigator Kaiser Permanente Northern California
David Magid, MD, MPH, Co-Investigator Kaiser Permanente Colorado
John Schmelzer, PhD, Co-Investigator Marshfield Clinic Research Foundation
Matthew Gillman, MD, SM, Co-Investigator Harvard Pilgrim Health Care
Steve Steinhubl, MD, Co-Investigator Geisinger Health System

Study Summary

The CVRN WAVE Study dataset is comprised of patients who have been newly prescribed warfarin as anticoagulation therapy for the treatment of atrial fibrillation (AF) or venous thromboembolism (VTE). The cohort is comprised of adults who newly started warfarin between January 1, 2004 and December 31, 2013.  The CVRN WAVE dataset includes patient data from five participating sites: Kaiser Permanente Northern California (KPNC), Kaiser Permanente Colorado (KPCO), Harvard Pilgrim Health Care (HPHC), Marshfield Clinic Research Foundation (MCRF), and Geisinger Health System (GHS). Each of the participating sites followed the same data collection steps and transferred all their data to KPNC, where it was compiled to produce an analytic dataset with a single, common structure. The CVRN WAVE dataset provides a contemporary real-world assessment of the quality of control and persistence of warfarin therapy for patients with AF and VTE in large, community-based network of clinical practices. The compiled dataset is hosted at KPNC and may be analyzed as a whole or may be broken down by site. 


The CVRN WAVE cohort consists of 34, 331 adults aged 21 years or older at the time of newly prescribed warfarin. They must also have an AF diagnosis with a least one outpatient International Normalized Ratio (INR) measurement after the qualifying warfarin prescription. 

Table 1. CVRN WAVE Dataset Member Counts by Site

​Number of Members
Percent of Dataset​
​Kaiser Permanente Northern California
Kaiser Permanente Colorado​
Harvard Pilgrim Health Care​1,499​
​Marshfield Clinic Research Foundation
Geisinger Health System​1,167​
Total​ 34,331​

Cohort Characteristics

Figure 1. Distribution of Age and Gender for 34,331 Subjects in the CVRN WAVE Study

Figure 2. Distribution of Race for 34,331 Subject in the CVRN WAVE Study

Data Source

All member data was extracted using the Virtual Data Warehouse (VDW). The VDW is a standardized resource comprised of: (1) computerized datasets stored behind separate security firewalls, including variables with identical names, formats, and specifications; (2) informatics tools that facilitate storage, retrieval, processing, and managing the datasets; and (3) detailed data documentation. All data are linked by a unique identifier so that data elements can be rolled up to the individual person-level. Determining the exact time and duration of warfarin therapy is complicated since dosing may be changed in response to International Normalized Ratio (INR) tests done at varying frequency. Therefore, a typical "90-day supply" of warfarin may last more or less than 90 days. Using a previously validated approach patient`s longitudinal warfarin exposure is based on the number of days` supply per prescription and timing of outpatient INRs.

Key Publications

Baumgartner, C., Fan, D., Fang, M. C., Singer, D. E., Witt, D. M., Williams, M. S., ... & Go, A. S. (2017). Anxiety but Not Depression Influences Risk of Stroke in Adults With Atrial Fibrillation: CVRN WAVE Study. Circulation136(suppl_1), A14586-A14586

Go, A. S., Fan, D., Chang, Y., Chan, J., Lieu, T. A., Magid, D. J., ... & Sung, S. H. (2010). Quality of anticoagulation management in atrial fibrillation and venous thromboembolism: the CVRN WAVE study.