National Assessment of Warfarin Anticoagulation Therapy for Stroke Prevention in Atrial Fibrillation Jeffrey S. Dlott, Roberta A. George, Xiaohua Huang, Mouneer Odeh, Harvey W. Kaufman, Jack Ansell and Elaine M. Hylek Circulation. 2014;129:1407-1414; originally published online February 3, 2014; doi: 10.1161/CIRCULATIONAHA.113.002601 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 2014 American Heart Association, Inc. All rights reserved. Print ISSN: 0009-7322. Online ISSN: 1524-4539
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Stroke National Assessment of Warfarin Anticoagulation Therapy for Stroke Prevention in Atrial Fibrillation Jeffrey S. Dlott, MD; Roberta A. George, MS; Xiaohua Huang, MS; Mouneer Odeh, MS; Harvey W. Kaufman, MD; Jack Ansell, MD; Elaine M. Hylek, MD Background—Anticoagulation control with warfarin, as assessed by the international normalized ratio (INR), is challenging. Time in the therapeutic range has been inversely correlated with major hemorrhage, thrombosis, and mortality. Quest Diagnostics offers standardized INR laboratory testing services to approximately half of US physician practices. To inform national stroke prevention strategies, we evaluated anticoagulation control in office-based community practices. Methods and Results—We selected individuals with ≥2 months of INR data, INR results of >1.2, and an ICD-9 diagnosis code of atrial fibrillation. Frequency of INR testing and time in the therapeutic range were analyzed by age, sex, length of testing period, number of referred patients per provider, and median household income (based on home ZIP code). We identified 138 319 individuals referred by 37 939 physicians, yielding a total of 2 683 674 INR results. Patients had a mean age of 74 years; 81% were ≥65 years of age, and 55% were ≥75 years of age. The mean time in the therapeutic range was 53.7% overall and improved with time on treatment, increasing from 47.6% for patients with 60 days were excluded, as were individuals with extreme testing frequency (>100 annualized tests). Finally, INR data from hospitals (medical centers) were excluded to avoid patients who may have been hospitalized or managed by hospital-based anticoagulation clinics. INR test results were extracted from the Quest Diagnostics Data Warehouse, along with patient demographics and insurance type. Age was categorized into 7 groups. Economic status was assigned by use of the median income from the 2007 US Census from the patient’s home ZIP code. Median income was categorized into 5 ranges. This study was determined to be exempt from institutional review by the Western Institutional Review Board (Olympia, WA).
Table 1. Atrial Fibrillation Patient Characteristics, INR Frequency, and TTR Patients’ Study Time All (n=138 319)
4.0
125 325 (4.7)
26 509 (6.4)
98 816 (4.4)
TTR, mean (SD), %
53.7 (23.3)
47.6 (27.3)
57.5 (19.6)
1: CT, ME, MA, NH, RI, VT
56.8 (21.7)
50.4 (26.0)
60.0 (18.3)
2: NJ, NY
54.0 (23.2)
47.7 (27.2)
57.4 (19.8)
3: DE, DC, MD, PA, VA, WV
55.4 (22.1)
48.3 (26.3)
58.7 (19.0)
4: AL, FL, GA, KY, MS, NC, SC, TN
52.8 (24.5)
48.2 (28.4)
56.4 (20.2)
5: IL, IN, MI, MN, OH, WI
53.3 (23.8)
47.6 (27.4)
57.2 (20.1)
6: AR, LA, NM, OK, TX
49.1 (24.9)
43.4 (27.8)
53.6 (21.4)
7: IA, KS, MO, NE
56.7 (22.5)
50.4 (27.4)
59.9 (18.8)
8: CO, MT, ND, SD, UT, WY
51.8 (25.4)
46.0 (28.1)
58.1 (20.1)
9: AZ, CA, HI, NV
51.9 (23.5)
46.1 (27.2)
55.8 (19.7)
10: AK, ID, OR, WA
58.8 (22.7)
56.3 (26.1)
61.2 (18.4)
Medicare
66 531 (49.8)
25 067 (49.8)
41 464 (49.7)
Private insurance
63 616 (47.6)
23 133 (45.9)
40 483 (48.6)
3572 (2.7)
2172 (4.3)
1400 (1.7)
TTR, geographic region and states, mean (SD), %
Insurance type, n (%)
Other
INR indicates international normalized ratio; and TTR, time in therapeutic range
Downloaded from http://circ.ahajournals.org/ at YORK UNIV SCOTT LIB on July 2, 2014
Dlott et al Anticoagulant Management in the United States 1409
Laboratory
recombinant human source of tissue factor is used. All assays were performed with Siemens automated coagulation analyzers. Quality control procedures include both validation and surveillance correlation analyses for each instrument/reagent combination across the reportable INR
All Quest Diagnostics laboratories (>100) in the United States use a standard thromboplastin reagent from the same lot with an International Sensitivity Index of 0.97 (Innovin, Siemens, Marburg, Germany). A
A
65
30
Study Time
The online version of this article, along with updated information and services, is located on the World Wide Web at: http://circ.ahajournals.org/content/129/13/1407
Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Circulation can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Circulation is online at: http://circ.ahajournals.org//subscriptions/
Downloaded from http://circ.ahajournals.org/ at YORK UNIV SCOTT LIB on July 2, 2014
Stroke National Assessment of Warfarin Anticoagulation Therapy for Stroke Prevention in Atrial Fibrillation Jeffrey S. Dlott, MD; Roberta A. George, MS; Xiaohua Huang, MS; Mouneer Odeh, MS; Harvey W. Kaufman, MD; Jack Ansell, MD; Elaine M. Hylek, MD Background—Anticoagulation control with warfarin, as assessed by the international normalized ratio (INR), is challenging. Time in the therapeutic range has been inversely correlated with major hemorrhage, thrombosis, and mortality. Quest Diagnostics offers standardized INR laboratory testing services to approximately half of US physician practices. To inform national stroke prevention strategies, we evaluated anticoagulation control in office-based community practices. Methods and Results—We selected individuals with ≥2 months of INR data, INR results of >1.2, and an ICD-9 diagnosis code of atrial fibrillation. Frequency of INR testing and time in the therapeutic range were analyzed by age, sex, length of testing period, number of referred patients per provider, and median household income (based on home ZIP code). We identified 138 319 individuals referred by 37 939 physicians, yielding a total of 2 683 674 INR results. Patients had a mean age of 74 years; 81% were ≥65 years of age, and 55% were ≥75 years of age. The mean time in the therapeutic range was 53.7% overall and improved with time on treatment, increasing from 47.6% for patients with 60 days were excluded, as were individuals with extreme testing frequency (>100 annualized tests). Finally, INR data from hospitals (medical centers) were excluded to avoid patients who may have been hospitalized or managed by hospital-based anticoagulation clinics. INR test results were extracted from the Quest Diagnostics Data Warehouse, along with patient demographics and insurance type. Age was categorized into 7 groups. Economic status was assigned by use of the median income from the 2007 US Census from the patient’s home ZIP code. Median income was categorized into 5 ranges. This study was determined to be exempt from institutional review by the Western Institutional Review Board (Olympia, WA).
Table 1. Atrial Fibrillation Patient Characteristics, INR Frequency, and TTR Patients’ Study Time All (n=138 319)
4.0
125 325 (4.7)
26 509 (6.4)
98 816 (4.4)
TTR, mean (SD), %
53.7 (23.3)
47.6 (27.3)
57.5 (19.6)
1: CT, ME, MA, NH, RI, VT
56.8 (21.7)
50.4 (26.0)
60.0 (18.3)
2: NJ, NY
54.0 (23.2)
47.7 (27.2)
57.4 (19.8)
3: DE, DC, MD, PA, VA, WV
55.4 (22.1)
48.3 (26.3)
58.7 (19.0)
4: AL, FL, GA, KY, MS, NC, SC, TN
52.8 (24.5)
48.2 (28.4)
56.4 (20.2)
5: IL, IN, MI, MN, OH, WI
53.3 (23.8)
47.6 (27.4)
57.2 (20.1)
6: AR, LA, NM, OK, TX
49.1 (24.9)
43.4 (27.8)
53.6 (21.4)
7: IA, KS, MO, NE
56.7 (22.5)
50.4 (27.4)
59.9 (18.8)
8: CO, MT, ND, SD, UT, WY
51.8 (25.4)
46.0 (28.1)
58.1 (20.1)
9: AZ, CA, HI, NV
51.9 (23.5)
46.1 (27.2)
55.8 (19.7)
10: AK, ID, OR, WA
58.8 (22.7)
56.3 (26.1)
61.2 (18.4)
Medicare
66 531 (49.8)
25 067 (49.8)
41 464 (49.7)
Private insurance
63 616 (47.6)
23 133 (45.9)
40 483 (48.6)
3572 (2.7)
2172 (4.3)
1400 (1.7)
TTR, geographic region and states, mean (SD), %
Insurance type, n (%)
Other
INR indicates international normalized ratio; and TTR, time in therapeutic range
Downloaded from http://circ.ahajournals.org/ at YORK UNIV SCOTT LIB on July 2, 2014
Dlott et al Anticoagulant Management in the United States 1409
Laboratory
recombinant human source of tissue factor is used. All assays were performed with Siemens automated coagulation analyzers. Quality control procedures include both validation and surveillance correlation analyses for each instrument/reagent combination across the reportable INR
All Quest Diagnostics laboratories (>100) in the United States use a standard thromboplastin reagent from the same lot with an International Sensitivity Index of 0.97 (Innovin, Siemens, Marburg, Germany). A
A
65
30
Study Time
