Ekonomi Bölümü Koleksiyonu

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Citation - WoS: 3
Citation - Scopus: 4
Does Credit Composition Matter for Current Account Dynamics? Evidence From Turkey
(Taylor & Francis, 2016) Toraganlı, Nazlı; Ertuğrul, Hasan Murat
Based on a dynamic approach using the Kalman filter we depict effects of time-varying interactions between different components of credit stock on the current account in the Turkish Economy for the period 2002Q3–2014Q3. We decompose the credit stock into consumer and non-financial corporate sector credit and show empirically that both types of credit stock have negative effects on the current account dynamics
Citation - Scopus: 8
Patterns of Treatment and Correction of Hyponatremia in Intensive Care Unit Patients
(W.B. Saunders, 2015) Badawi, Omar; Chiodo, Joseph; Waikar, Sushrut S.; Boklage, Susan; Dasta, Joseph; Xie, Lin; Başer, Onur
Purpose: The goal of this study was to examine the real-world patterns of care and interventions among intensive care unit (ICU) patients with hypervolemic and euvolemic hyponatremia using a large clinical database. Materials and Methods: The Phillips eICU Research Institute database was used to investigate hyponatremia treatment patterns and trends, mortality, and ICU and hospital length of stay. Demographics, clinical characteristics, and outcome variables were compared in patients corrected for hyponatremia using both a more strict and a less strict definition. Results: At admission, 35%, 55%, and 10% of patients had mild, moderate, and severe hyponatremia, respectively. At the end of an ICU stay, the percentage of patients who did not have corrected serum sodium concentration was 48% (using a more strict definition) and 24% (using a less strict definition). Using either definition of correction, patients with serum sodium correction had lower mortality and longer survival than did patients without corrected serum sodium concentration. Conclusions: A significant proportion of hyponatremia is not corrected during an ICU stay. Critically ill patients with hyponatremia who have their serum sodium corrected have lower mortality and longer survival, highlighting the need for more attention to hyponatremia and its correction in critically ill patients. © 2015 Elsevier Inc.
Citation - WoS: 17
Citation - Scopus: 23
Benefit of Early Discharge Among Patients With Low-Risk Pulmonary Embolism
(2017) Wang, Li; Wells, Phil; Fermann, Gregory J; Peacock, W. Frank; Schein, Jeff; Coleman, Craig I; Crivera, Concetta; Başer, Onur
Clinical guidelines recommend early discharge of patients with low-risk pulmonary embolism (LRPE). This study measured the overall impact of early discharge of LRPE patients on clinical outcomes and costs in the Veterans Health Administration population. Adult patients with >= 1 inpatient diagnosis for pulmonary embolism (PE) (index date) between 10/2011-06/2015, continuous enrollment for >= 12 months pre-and 3 months post-index date were included. PE risk stratification was performed using the simplified Pulmonary Embolism Stratification Index. Propensity score matching (PSM) was used to compare 90-day adverse PE events (APEs) [recurrent venous thromboembolism, major bleed and death], hospital-acquired complications (HACs), healthcare utilization, and costs among short (<= 2 days) versus long length of stay (LOS). Net clinical benefit was defined as 1 minus the combined rate of APE and HAC. Among 6,746 PE patients, 95.4% were men, 22.0% were African American, and 1,918 had LRPE. Among LRPE patients, only 688 had a short LOS. After 1:1 PSM, there were no differences in APE, but short LOS had fewer HAC (1.5% vs 13.3%, 95% CI: 3.77-19.94) and bacterial pneumonias (5.9% vs 11.7%, 95% CI: 1.24-3.23), resulting in better net clinical benefit (86.9% vs 78.3%, 95% CI: 0.84-0.96). Among long LOS patients, HACs (52) exceeded APEs (14 recurrent DVT, 5 bleeds). Short LOS incurred lower inpatient ($2,164 vs $5,100, 95% CI: $646.8-$5225.0) and total costs ($9,056 vs $12,544, 95% CI: $636.6-$6337.7). LRPE patients with short LOS had better net clinical outcomes at lower costs than matched LRPE patients with long LOS.
Citation - WoS: 7
Citation - Scopus: 7
Market Access and Regional Dispersion of Human Capital Accumulation in Turkey
(Wiley, 2020) Karahasan, Burhan Can; Bilgel, Fırat
Building on early advances in development economics, the theoretical construct of new economic geography asserts that geography plays a crucial role in educational human capital accumulation. Based on this expectation, this study investigates the impact of market access on provincial human capital accumulation in Turkey. Results indicate that market access matters for understanding why some regions lag behind others in terms of average years of schooling. Our results are robust to the inclusion of spatial mechanisms, different specifications of the spatial weight matrix, endogeneity and alternative measurements of market access and to a host of other factors that affect regional human capital accumulation.
Citation - WoS: 5
Citation - Scopus: 5
Evidence for Financial Contagion in Endogenous Volatile Periods
(Wiley, 2015) Ulusoy, Veysel; Kılıç, Erdem
The objective of this study is to analyze cross-border contagious dynamics in both foreign exchange markets and stock exchange markets. Propagation is analyzed with respect to the transmission of excessive volatility that is endogenously determined. The contagion process is discussed in the context of financial systems, foreign direct investments and trade. Implementing a vector autoregressive-multivariate generalized autoregressive conditional heteroskedasticity (VAR-MGARCH) model, we show that country-specific turbulence in financial markets is able to create unanticipated financial contagion across countries. Diversified trade and financial relations decrease the risk of exposure to contagion from external markets. The world's largest economies, however, play a price-setter role, and diversification is of secondary importance. Asymmetric transmission of the empirically predicted contagion prevails in the latter case.
Citation - WoS: 6
Citation - Scopus: 9
Gendering Resistance: Multiple Faces of the Kurdish Women's Struggle
(Wiley, 2019) Göksel, Nisa
The article explores the Kurdish women's movement in Turkey by bridging two forms of resistance: those of guerrilla women fighters and of activist women. Based on my extensive ethnographic and archival research, I ask how women under conditions of war engage in different modes of resistance. In what ways does the "heroic resistance" of guerrilla women resonate with and/or contradict the everyday, "ordinary" struggles of activist women? The potent image of the Kurdish guerrilla woman that emerged in the early 1990s is constitutive of many other modes of political subjectivities, even among women who do not or cannot become guerrillas. One of those subjectivities is that of the activist woman. My analysis suggests that women's activism opens up a middle ground of action between "heroic" and "ordinary" resistance by reconciling revolutionary politics with everyday activism around gender-based violence, democracy, and human rights. Although both revolutionary movement participants and scholars of revolutionary resistance often contrast the "ordinary" with the realm of armed resistance, this article challenges this dichotomy. I take the two realms of resistance-the ordinary and the heroic-as the core constituents of revolutionary resistance, and I reconsider the gendered interplay between them.
Citation - WoS: 4
Citation - Scopus: 6
Does the Unification of Health Financing Affect the Distribution Pattern of Out-Of Health Expenses in Turkey?
(Wiley, 2019) Çınaroğlu, Songül; Başer, Onur
Turkey has implemented health reforms for over a decade and has taken significant steps toward unifying health financing. This study investigated the financial burden associated with out-of-pocket (OOP) expenditures under universal health coverage, using national 2003–2015 household budget data from the Turkish Statistical Institute. Progress was evaluated using Kakwani–Suits indices and Lorenz concentration curves. The results indicate that overall, more than a decade after its unification, redistribution of wealth in the Turkish health financing system has benefitted the wealthy but not the poor. Both curve and index approaches (Kakwani index 2003 = -0.50; 2015 = -0.44) reveal an increasingly regressive pattern of OOP health expenditures. The effective use of fiscal space and good political leadership are essential for the successful continuation of reforms to combat poverty in Turkey.
Citation - WoS: 17
Citation - Scopus: 20
Consumer Confidence and Economic Activity: a Factor Augmented Var Approach
(Taylor & Francis, 2016) Kılıç, Erdem; Çankaya, Serkan
This study aims to analyse the effects of the consumer confidence on economic activity for the USmarket. We use the empirical factor-augmented vector autoregression (FAVAR) method, whichenables us to incorporate a wide range of economic activity factors into the analysis. Theconsumer confidence index (CCI) is chosen as the principal variable that is presumed to representthe degree of optimism on the state of economic activity. The results show that consumerconfidence and economic activity are strongly correlated for manufacturing-related factors,such as industrial production and inventories. We also observe strong relation among CCI andpersonal consumption expenditures, as well as housing market variables.
Citation - WoS: 30
Citation - Scopus: 29
Out-Of Inr Values and Outcomes Among New Warfarin Patients With Non-Valvular Atrial Fibrillation
(2015) Schein, Jeffrey R; Wang, Li; Damaraju, Chandrasekharrao, V; Nelson, Winnie W; Başer, Onur
Background Although efficacious in stroke prevention in non-valvular atrial fibrillation, many warfarin patients are sub-optimally managed. Objective To evaluate the association of international normalized ratio control and clinical outcomes among new warfarin patients with non-valvular atrial fibrillation. Setting Adult non-valvular atrial fibrillation patients (a parts per thousand yen18 years) initiating warfarin treatment were selected from the US Veterans Health Administration dataset between 10/2007 and 9/2012. Method Valid international normalized ratio values were examined from the warfarin initiation date through the earlier of the first clinical outcome, end of warfarin exposure or death. Each patient contributed multiple in-range and out-of-range time periods. Main outcome measure The relative risk ratios of clinical outcomes associated with international normalized ratio control were estimated. Results 34,346 patients were included for analysis. During the warfarin exposure period, the incidence of events per 100 person-years was highest when patients had international normalized ratio < 2:13.66 for acute coronary syndrome; 10.30 for ischemic stroke; 2.93 for transient ischemic attack; 1.81 for systemic embolism; and 4.55 for major bleeding. Poisson regression confirmed that during periods with international normalized ratio < 2, patients were at increased risk of developing acute coronary syndrome (relative risk ratio: 7.9; 95 % confidence interval 6.9-9.1), ischemic stroke (relative risk ratio: 7.6; 95 % confidence interval 6.5-8.9), transient ischemic attack (relative risk ratio: 8.2; 95 % confidence interval 6.1-11.2), systemic embolism (relative risk ratio: 6.3; 95 % confidence interval 4.4-8.9) and major bleeding (relative risk ratio: 2.6; 95 % confidence interval 2.2-3.0). During time periods with international normalized ratio > 3, patients had significantly increased risk of major bleeding (relative risk ratio: 1.5; 95 % confidence interval 1.2-2.0). Conclusion In a Veterans Health Administration non-valvular atrial fibrillation population, exposure to out-of-range international normalized ratio values was associated with significantly increased risk of adverse clinical outcomes.
Citation - WoS: 46
Citation - Scopus: 70
Adoption and Use of Learning Management Systems in Education: the Role of Playfulness and Self-Management
(MDPI [Commercial Publisher], 2021) Akküçük, Ulaş; Balkaya, Selen
This article investigates the factors affecting primary and secondary education teachers' behavioral intention to adopt learning management systems (LMSs). Information technology (IT) innovations have the power to change the way we work, educate, learn, and basically the way we live. The effect of IT innovations on education makes it critical to understand the current usage situation of LMSs and the factors affecting their adoption by teachers. The unified theory of acceptance and use of technology (UTAUT) was extended with factors from education and game-based learning literature. In order to see the effect of individual- and organizational-level characteristics, multi-group structural equation modeling (SEM) analysis was conducted and discrepancies in relationships were reported. Evaluation of users and non-users and teachers of different fields were also compared to each other. The findings of this study not only contribute to theory through the development and testing of a thorough model relating technology features and individual characteristics to behavioral intention to use, but also offer strong implications for practitioners who would like to increase LMS usage and create a more effective learning environment.
Citation - WoS: 5
Citation - Scopus: 3
Exports, Real Exchange Rates and Dollarization: Empirical Evidence From Turkish Manufacturing Firms
(Springer, 2019) Karamollaoğlu, Nazlı; Yalçın, Cihan
We attempt to uncover the relationship between the real exchange rates and exports shares of manufacturing firms in Turkey by taking into account FX exposures and various firm characteristics. We use a large panel of manufacturing firms to carry out an empirical analysis for the period 2002–2010. Contrary to macro-evidence, firm-level empirical evidence suggests that a depreciation of the Turkish lira seems to favor the external competitiveness of firms in general. We document that a real depreciation of the Turkish lira has a positive impact on export shares and its impact is muted to some extent for firms operating in sectors that use imported inputs intensively. In addition, we estimate that export shares increase as a result of real depreciation for firms having low (naturally hedged) and moderate FX debt-to-export ratios. We do not confirm a strong balance sheet channel where a depreciation of the currency may harm firms’ export performance due to currency mismatch. On the contrary, FX borrowing is estimated to support export performance probably due to undermining finance constraints.
Citation - WoS: 25
Citation - Scopus: 25
Impact of Switching From an Initial Tumor Necrosis Factor Inhibitor on Health Care Resource Utilization and Costs Among Patients With Rheumatoid Arthritis
(2015) Roy, Sanjoy; Ganguli, Arijit; Xie, Lin; Başer, Onur; Cifaldi, Mary
Purpose: Despite improved clinical outcomes for the majority of patients, nearly 30% of patients with rheumatoid arthritis (RA) who initiate tumor necrosis factor antagonist (anti-TNF) biologic agents fail to respond to their first-line anti-TNF and switch to another anti-TNF or a non-TNF biologic. How this change affects health care costs and resource utilization is unknown. We therefore compared RA patients taking first-line anti-TNFs who switched to a second anti-TNF versus those patients who switched to an alternate biologic. Methods: Health care claims data were obtained from a large US database for eligible adults with confirmed RA diagnoses who initiated anti-TNF treatment and switched to another biologic. Health care costs and utilization during the first 12 months' postswitch were compared. Generalized linear models were used to adjust for differences in demographic and clinical characteristics before switching. Findings: Patients who switched to a second anti-TNF rather than a non-TNF biologic were generally younger (53.0 vs. 55.3 years; P < 0.0001) and less likely to be female (79.7% vs. 82.7%; P = 0.0490). Of the 3497 eligible patients who switched from first-line anti-TNFs, 2563 (73.3%) switched to another anti-TNF and 934 (26.7%) switched to a non-TNF. Adalimumab was the most frequently prescribed (43.4%) second-line anti-TNF, and abatacept was the most common non anti-TNF (71.4%). Patients who switched to a second anti-TNF remained on their first medication for a significantly shorter period (342.5 vs 420.6 days; P < 0.0001) and had lower comorbidity indices and higher disease severity at baseline than those who switched to a non anti-TNF. After adjusting for baseline differences, patients who switched to second anti-TNFs versus a non-TNF incurred lower RA-related costs ($20,938.9 vs $22,645.2; P = 0.0010) and total health care costs ($34,894.6 vs $38,437.2; P = 0.0010) 1 year postswitch. These differences were driven by increased physician office visit costs among the non-TNF group. Implications: Among the anti-TNF initiators who switched therapy, more patients switched to a second anti-TNF than to a non-TNF. Switching to a second anti-TNF treatment was associated with lower all-cause and RA-related health care costs and resource utilization than switching to a non-TNF. Because switching therapy may be unavoidable, finding a treatment algorithm mitigating this increase to any extent should be considered. These data are limited by their retrospective design. Additional confounding variables that could not be controlled for may affect results. (C) 2015 The Authors. Published by Elsevier HS journals, Inc.
Citation - WoS: 7
Citation - Scopus: 8
Hematocrit Levels and Thrombotic Events in Patients With Polycythemia Vera: an Analysis of Veterans Health Administration Data
(Springer, 2019) Parasuraman, Shreekant; Robyn Scherber; Jingbo Yu; Li Wang; Dilan Paranagama; Sulena Shrestha; Başer, Onur
Patients with polycythemia vera (PV) have a high incidence of thrombotic events (TEs), contributing to a greater mortality risk than the general population. The relationship between hematocrit (HCT) levels and TE occurrence among patients with PV from the Veterans Health Administration (VHA) was evaluated to replicate findings of the CYTO-PV trial with a real-world patient population. This retrospective study used VHA medical record and claims data from the first claim with a PV diagnosis (index) until death, disenrollment, or end of study, collected between October 1, 2005, and September 30, 2012. Patients were aged ? 18 years at index, had ? 2 claims for PV (ICD-9-CM code, 238.4) ? 30 days apart during the identification period, continuous health plan enrollment from 12 months pre-index until end of study, and ? 3 HCT measurements per year during follow-up. This analysis focused on patients with no pre-index TE, and with all HCT values either < 45% or ? 45% during the follow-up period. The difference in TE risk between HCT groups was assessed using unadjusted Cox regression models based on time to first TE. Patients (N = 213) were mean (SD) age 68.9 (11.5) years, 98.6% male, and 61.5% white. TE rates for patients with HCT values < 45% versus ? 45% were 40.3% and 54.2%, respectively. Among patients with ? 1 HCT before TE, TE risk hazard ratio was 1.61 (95% CI, 1.03–2.51; P = 0.036). This analysis of the VHA population further supports effective monitoring and control of HCT levels < 45% to reduce TE risk in patients with PV.
Citation - WoS: 1
Citation - Scopus: 1
Great Recession and News Shocks: Evidence Based on an Estimated Dsge Model
(Springer, 2021) Nebioğlu, Deniz
This paper examines whether productivity news shocks were among the drivers of the Great Recession. To do this, the Smets and Wouters (Am Econ Rev 97(3):586–606, 2007. https://doi.org/10.1257/aer.97.3.586) model is extended by a generalized preference specification which allows for scaling wealth effects on the labor supply. The resulting model is estimated using Bayesian methods which draw upon the US data from the period 1965Q2 to 2014Q3. There are four main results: (i) Estimation of the model is inconclusive regarding the degree of wealth elasticity of the labor supply. As a result, two complementary versions of the model prevail, each of which has differing implications for the transmission and the quantitative importance of exogenous shocks. (ii) When the degree of wealth elasticity of the labor supply is low, news shocks replace risk premium shocks, suggesting that news shocks are one possible reason for fluctuations in US business cycles. (iii) When the Great Recession period is analyzed through the lenses of the two complementary versions of the model, two explanations emerge as potential reasons behind the deepening of the crisis: worsening credit conditions as well as the collapse of over-optimistic expectations regarding future productivity. (iv) For both model specifications, general developments in productivity are estimated to be positive. Therefore, productivity slowdown is not considered to be among the reasons for the emergence or persistence of the Great Recession.
Unemployment Polarisation and Club Convergence in Türkiye
(Wiley, 2025) Karahasan, Burhan Can
Turkish economy has undergone massive transformation during the 2000s. Annual economic growth reached a peak of 10% in the early 2000s. However, the side effects of global financial crises and the internal macroeconomic imbalances shift the growth trajectory of T & uuml;rkiye into a new path of unstable economic growth. While macroeconomic consequences are densely discussed we know less about the adjustment of local labour markets. To fill this gap, we examine the club formation of Turkish regions by analysing their unemployment trajectories during the post 2000s. Our findings show that despite rapid economic growth Turkish regions get extremely polarised and form distinct convergence clubs. Remarkably polarisation is higher for the female population. Geographically, polarisation is in the form of an isolation for the least developed south-eastern regions and some of the developed urbanised western regions. Additionally, our robustness exercises indicate higher polarisation after 2013 as Turkish economic growth starts to become more volatile and less sustainable. Finally, our spatial extensions show that impact of spatial proximity has significant influence on the accurate extent of unemployment deprivation.
State Gun Control Laws, Gun Ownership and the Supply of Homicide Organ Donors
(Elsevier, 2020) Bilgel, Fırat
The likelihood of being a potential deceased organ donor is higher for individuals who have been exposed to situations typically characterized by a severe head trauma or stroke that result in brain death. Employing count data models that account for overdispersion and/or excessive counts of zeros, this paper assesses the unintended consequences of enforcing stricter gun control laws and the effects of gun ownership on homicide organ donor supply in the United States using county data for the period 2009–2015. The findings confirm the transplantation paradox hypothesis that stricter gun control laws reduce the expected cases of gun homicides and thereby reduce deceased organ donor supply and exacerbate the organ shortage. The findings are robust to several measures of the strength of gun control laws, restricted samples and spurious outcome variables. However, the direction of the impact of gun ownership levels on homicide organ donor supply proved to be inconclusive.
Citation - WoS: 17
Citation - Scopus: 19
Oil Prices and Economic Activity in Brics and G7 Countries
(Springer, 2019) Kılıç, Erdem; Çankaya, Serkan
The effect of oil prices on countries’ economic activity has been the center of attention for decades. The empirical link between oil prices and economic activity has been steadily investigated during this time period but the measured outcomes have revealed mixed results and been inconsistent. This study examines the effect of oil prices on economic activity for Brazil, Russia, India, China, and South Africa (BRICS) and Group of Seven (G7) countries in both short-run and long-run relationships by estimating a maximum likelihood structural vector autoregression model. The model shows that a positive shock to oil prices tends to affect the monetary aggregate in Brazil, Canada, France, Germany, and Russia. The effect on interest rate spread is most significant in India and Russia. Impulse response functions display almost no effect on the gross domestic product in the US and China. A positive response on the consumer price index is observed mostly for developed countries. The response of real exchange rate reveals a positive effect on all countries in varying degrees, with the exception of the US and South Africa. Finally, Granger causality tests were conducted with proper allowance for the non-stationarity of the data. The findings illustrate that the Russian economy is among the economies that are most significantly affected by oil price fluctuations for almost all the selected variables. The models also reveal that the effect of oil price shocks on the US’s and China’s economic activities is only limited to the effect on real exchange rates. Other variables show no or limited reactions to oil prices. We also used the Markov switching maximum likelihood vector autoregression models, which reveals similar results.
Understanding Covid-19 Mobility Through Human Capital: a Unified Causal Framework
(Springer, 2023) Bilgel, Fırat; Karahasan, Burhan Can
This paper seeks to identify the causal impact of educational human capital on social distancing behavior at workplace in Turkey using district-level data for the period of April 2020 - February 2021. We adopt a unified causal framework, predicated on domain knowledge, theory-justified constraints anda data-driven causal structure discovery using causal graphs. We answer our causal query by employing machine learning prediction algorithms; instrumental variables in the presence of latent confounding and Heckman's model in the presence of selection bias. Results show that educated regions are able to distance-work and educational human capital is a key factor in reducing workplace mobility, possibly through its impact on employment. This pattern leads to higher workplace mobility for less educated regions and translates into higher Covid-19 infection rates. The future of the pandemic lies in less educated segments of developing countries and calls for public health action to decrease its unequal and pervasive impact.
Citation - WoS: 40
Citation - Scopus: 39
Clinical and Economic Burden Associated With Cardiovascular Events Among Patients With Hyperlipidemia: a Retrospective Cohort Study
(2016) Wang, Li; Quek, Ruben G. W; Fox, Kathleen M; Gandra, Shravanthi R; Li, Lu; Başer, Onur
Background: Annual direct costs for cardiovascular (CV) diseases in the United States are approximately $195.6 billion, with many high-risk patients remaining at risk for major cardiovascular events (CVE). This study evaluated the direct clinical and economic burden associated with new CVE up to 3 years post-event among patients with hyperlipidemia. Methods: Hyperlipidemic patients with a primary inpatient claim for new CVE (myocardial infarction, unstable angina, ischemic stroke, transient ischemic attack, coronary artery bypass graft, percutaneous coronary intervention and heart failure) were identified using IMS LifeLink PharMetrics Plus data from January 1, 2006 through June 30, 2012. Patients were stratified by CV risk into history of CVE, modified coronary heart disease risk equivalent, moderate-and low-risk cohorts. Of the eligible patients, propensity score matched 243,640 patients with or without new CVE were included to compare healthcare resource utilization and direct costs ranging from the acute (1-month) phase through 3 years post-CVE date (follow-up period). Results: Myocardial infarction was the most common CVE in all the risk cohorts. During the acute phase, among patients with new CVE, the average incremental inpatient length of stay and incremental costs ranged from 4.4-6.2 days and $25,666-$30,321, respectively. Acute-phase incremental costs accounted for 61-75 % of first-year costs, but incremental costs also remained high during years 2 and 3 post-CVE. Conclusions: Among hyperlipidemic patients with new CVE, healthcare utilization and costs incurred were significantly higher than for those without CVE during the acute phase, and remained higher up to 3 years post-event, across all risk cohorts.
Citation - WoS: 59
Citation - Scopus: 60
Risk of Stroke/Systemic Embolism, Major Bleeding and Associated Costs in Non-Valvular Atrial Fibrillation Patients Who Initiated Apixaban, Dabigatran or Rivaroxaban Compared With Warfarin in the United States Medicare Population
(2017) Amin, Alpesh; Lien Vo; Trocio, Jeffrey; Keshishian, A; Liu, Xianchen; Mardekian, Jack; Zhang, Qisu; Rosenblatt, Lisa; Dina, Oluwaseyi; Başer, Onur; Le, Hannah
Objective: To compare the risk and cost of stroke/systemic embolism (SE) and major bleeding between each direct oral anticoagulant (DOAC) and warfarin among non-valvular atrial fibrillation (NVAF) patients. Methods: Patients (65 years) initiating warfarin or DOACs (apixaban, rivaroxaban, and dabigatran) were selected from the Medicare database from 1 January 2013 to 31 December 2014. Patients initiating each DOAC were matched 1:1 to warfarin patients using propensity score matching to balance demographics and clinical characteristics. Cox proportional hazards models were used to estimate the risks of stroke/SE and major bleeding of each DOAC vs. warfarin. Two-part models were used to compare the stroke/SE- and major-bleeding-related medical costs between matched cohorts. Results: Of the 186,132 eligible patients, 20,803 apixaban-warfarin pairs, 52,476 rivaroxaban-warfarin pairs, and 16,731 dabigatran-warfarin pairs were matched. Apixaban (hazard ratio [HR]=0.40; 95% confidence interval [CI] 0.31, 0.53) and rivaroxaban (HR=0.72; 95% CI 0.63, 0.83) were significantly associated with lower risk of stroke/SE compared to warfarin. Apixaban (HR=0.51; 95% CI 0.44, 0.58) and dabigatran (HR=0.79; 95% CI 0.69, 0.91) were significantly associated with lower risk of major bleeding; rivaroxaban (HR=1.17; 95% CI 1.10, 1.26) was significantly associated with higher risk of major bleeding compared to warfarin. Compared to warfarin, apixaban ($63 vs. $131) and rivaroxaban ($93 vs. $139) had significantly lower stroke/SE-related medical costs; apixaban ($292 vs. $529) and dabigatran ($369 vs. $450) had significantly lower major bleeding-related medical costs. Conclusions: Among the DOACs in the study, only apixaban is associated with a significantly lower risk of stroke/SE and major bleeding and lower related medical costs compared to warfarin.