May 5, 2016Open Access
View Full PaperClinical 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
Key Result
Medicaid insurance was not associated with lower overall use of oral anticoagulation compared to other insurance types (adjusted OR 0.82; 95% CI 0.61-1.09).
Study Design
Type
Observational (n=10,133)
Multicenter
Yes
Structured PICO
Does Medicaid insurance status affect the prescription rates of oral anticoagulation and clinical outcomes in adults with atrial fibrillation?
P
Population
10,133 adults with atrial fibrillation enrolled in a national outpatient registry, including 470 with Medicaid insurance, followed for 2 years.
E
Exposure
Medicaid insurance status
C
Comparator
Non-Medicaid insurance status
O
Outcome
Proportion of patients prescribed any oral anticoagulation (OAC; warfarin or novel oral anticoagulants [NOAC])
While Medicaid insurance is not associated with lower overall oral anticoagulation prescription rates in atrial fibrillation, it is associated with poorer anticoagulation control (lower time in therapeutic range) among warfarin users.
Main Result
Odds Ratio: 0.82 (95% CI 0.61–1.09)
Absolute Event Rate: 72.8% vs 76.3%
p-value: p=0.079
Abstract
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.