Clinical Characteristics, Oral Anticoagulation Patterns, and Outcomes of Medicaid Patients With Atrial Fibrillation: Insights From the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF I) Registry.


BACKGROUND: Whereas insurance status has been previously associated with care patterns, little is currently known about the association between Medicaid insurance and the clinical characteristics, treatment, or outcomes of patients with atrial fibrillation (AF). METHODS AND RESULTS: We used data from adults with AF enrolled in the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF), a national outpatient registry conducted at 176 community, multispecialty sites. The primary outcome of interest was the proportion of patients prescribed any oral anticoagulation (OAC; warfarin or novel oral anticoagulants [NOAC]). Secondary outcomes of interest included the proportion of patients prescribed NOACs (dabigatran or rivaroxaban); time in therapeutic range (TTR) for warfarin users, all-cause mortality, stroke/systemic embolism, and major bleed. Of 10 133 patients, N=470 (4.6%) had Medicaid insurance. Medicaid patients were similarly likely to receive OAC at baseline (72.8% vs 76.3%; unadjusted P=0.079), but less likely to receive NOAC at baseline or follow-up (12.1% vs 16.3%; unadjusted P=0.019). After risk adjustment, Medicaid status was associated with lower use of OAC at baseline among patients with high stroke risk (odds ratio [OR]=0.68; 95% CI=0.49, 0.94), but was not associated with OAC use overall (OR=0.82; 95% CI=0.61, 1.09). Among warfarin users, median TTR was lower among Medicaid patients (60% vs 68%; P<0.0001; adjusted TTR difference, -2.9; 95% CI=-5.7, -0.2; P=0.04). Use of an NOAC over 2 years of follow-up was not statistically different by insurance. Compared with non-Medicaid patients, Medicaid patients had higher unadjusted rates of mortality, stroke/systemic embolism, and major bleeding; however, these differences were attenuated following adjustment for clinical characteristics. CONCLUSIONS: In a contemporary AF cohort, use of OAC overall and use of NOACs were not significantly lower among Medicaid patients relative to others. However, among warfarin users, Medicaid patients spent less time in therapeutic range compared with those with other forms of insurance.





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Publication Info

O'Brien, Emily C, Sunghee Kim, Laine Thomas, Gregg C Fonarow, Peter R Kowey, Kenneth W Mahaffey, Bernard J Gersh, Jonathan P Piccini, et al. (2016). Clinical Characteristics, Oral Anticoagulation Patterns, and Outcomes of Medicaid Patients With Atrial Fibrillation: Insights From the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF I) Registry. J Am Heart Assoc, 5(5). 10.1161/JAHA.115.002721 Retrieved from

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Emily O'Brien

Associate Professor in Population Health Sciences

I am an epidemiologist and health services researcher at the Duke Clinical Research Institute. My research focuses on comparative effectiveness, patient-centered outcomes, and pragmatic health services research in cardiovascular and pulmonary disease.

Areas of expertise: Epidemiology, Health Services Research, and Clinical Decision Sciences


Laine Elliott Thomas

Professor of Biostatistics & Bioinformatics

As Deputy Director, Laine Thomas, PhD provides complementary leadership in strategy and development of the group and DCRI. She has an outstanding record of scientific and strategic collaboration, independent research, leadership and mentoring well known to her colleagues at the DCRI.

Thomas joined the DCRI in 2009. She serves as Associate Director for Biostatistics at DCRI and Associate Chair for Equity, Diversity and Inclusion within the Department of Biostatistics and Bioinformatics. She is a leader in developmental methods for observational and pragmatic studies. She has over 240 peer reviewed clinical and methodological publications arising from scientific collaboration in the therapeutic areas of cardiovascular disease, diabetes, uterine fibroids and SARS-CoV-2 virus. She led the statistical teams on the HERO COVID-19, ORBIT-AF I & II, ACTION-CMS, CHAMP-HF, and COMPARE-UF clinical registries and secondary analyses of the NAVIGATOR and ARISTOTLE clinical trials. She is the primary investigator of numerous methodological studies arising from these collaborations, addressing methods for causal inference in observational data, longitudinal treatment initiation, heterogeneous treatment effects and clinical trials augmented by external controls.

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