Ekonomi Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1936

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A Comparative Analysis of the Health Care Utilization and Costs of Patients Diagnosed With and Without Liver Cancer in the Us Medicare Population
(2017) Ogbomo, A.; Lin, Y.; Keshishian, A; Xie, L; Yuce, H; Başer, Onur
...
Citation - WoS: 6
Citation - Scopus: 8
Arbitrageur Behavior in Sentiment-Driven Asset-Pricing
(World Scientific Publishing, 2021) Kılıç, Erdem; Oğuzhan, Göksel
This study aims to model arbitrageur behavior in a sentiment-driven capital asset-pricing model under the premise of reflecting a more detailed decomposition of investor types in the equity markets. We explore the behavior and the impact of arbitrageur behavior, particularly, on pricing and on key financial ratios. We observe that the prevalence of the arbitrageur counteracts the effects of unsophisticated investors, resulting in a lower volatility of the price–dividend ratio, lower predictive power of changes in consumption for future price changes and lower equity premium. Thus, the results of our research allow us to conjecture that the extrapolation bias in the prices is lowered.
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: 3
Citation - Scopus: 3
Cancer Chemotherapy Treatment Patterns and Febrile Neutropenia in the Us Veterans Health Administration
(2014) Wang, Li; Dale, David C; Barron, Richard; Langeberg, Wendy J; Başer, Onur
Background: The Veterans Health Administration (VHA) is the largest integrated health care system in the United States and a major cancer care provider. Objective: To use VHA database to conduct a population-based study of patterns of myelosuppressive chemotherapy use and to assess the incidence and management of febrile neutropenia (FN) among VHA patients with lung, colorectal, or prostate cancer or non-Hodgkin lymphoma (NHL). Methods: Data were extracted for the initial myelosuppressive chemotherapy course for 27,899 patients who began treatment in the period 2006 to 2011. FN-related costs were defined as claims containing FN diagnosis. Results: Most patients were men (98.0%); most were 65 years or older (55.8%). Patients received a mean 3.4 to 3.9 chemotherapy cycles/course (median cycle duration 34-43 days). The incidence of FN among patients with lung, colorectal, or prostate cancer or NHL was 10.2%, 4.6%, 5.4%, and 17.3%, respectively. Primary or secondary prophylactic antibiotics/colony-stimulating factors were received by 21% and 12% of patients, respectively. Antibiotics were more commonly given as primary or secondary prophylaxis for patients with lung, colorectal, and prostate cancer; colony-stimulating factors were more common for patients with NHL. Among patients with FN, those with lung cancer had the highest inpatient mortality (10%); patients with NHL had the highest costs ($24,571) and the longest hospital length of stay (15.4 days). Conclusions: VHA cancer care was generally consistent with National Comprehensive Cancer Network recommendations; however, compared with the general population, chemotherapy cycles were longer, combination chemotherapy was used less, and treatment to prevent FN was used less, differences that may be attributed to the unique VHA patient population. The impact of these practices warrants further investigation.
Citation - WoS: 10
Citation - Scopus: 12
Contagion Effects of U.s. Dollar and Chinese Yuan in Forward and Spot Foreign Exchange Markets
(Elsevier, 2017) Kılıç, Erdem
Financial contagion in forex markets is modeled by the application of a bivariate Hawkes stochastic jumpprocess. The self-exciting and mutually exciting properties of the jump-clustering model allow for illustratinginternal and cross-sectional transmission processes. The results obtained suggest stronger effects from US tomutual markets than in the reverse case. Cross-sectional excitation dynamics in the spot markets are larger thanin the forward markets. As a central result, we can observe that the results for the Hawkes-model parameters aremore significant in the forward markets. Transmission dynamics beyond volatility determine the likelihood ofcontagion occurrence. The significance of the decay parameters towards the long term jump intensities supportsthe importance of abrupt fluctuations in the contagion discourse.
Demographic Distribution and Health Care Burden of Patients Diagnosed With Ankylosing Spondylitis in the Us Medicare Population
(2015) Mao, X; Li, L; Shrestha, S; Başer, Onur; Yuce, H; Wang, L
OBJECTIVES: To investigate the demographic distribution and health care burdenof patients diagnosed with ankylosing spondylitis (AS) using Medicare fee-forservice (FFS) data. METHODS: A retrospective analysis was performed using the100% Medicare FFS Datasets from October 1, 2008 through December 31, 2012.Patients diagnosed with AS were identified using International Classification ofDiseases, 9th Revision, Clinical Modification diagnosis code 720.0, and the firstdiagnosis date was designated as the index date. All patients were required tohave continuous medical and pharmacy benefits 1-year pre- (baseline period)and post-index date (follow-up period). Health care resource utilization and costsduring the baseline and follow-up periods were calculated. RESULTS: A total of8,990 AS patients were included in the study. The average age at diagnosis was 75years. Nearly 88.7% of patients were white, 62.97% were women and many residedin the South U.S. region (40.33%). The most common baseline comorbidities werechronic obstructive pulmonary disease (33.20%), diabetes (30.50%), cerebrovasculardisease (22.65%) and congestive heart failure (18.85%). During the follow-up period,73.04% of patients had inpatient admissions, 52.31% had emergency room visits,91.43% had outpatient office visits, 91.43% had outpatient visits and 57.67% hadpharmacy visits, resulting in average costs of, $37,077, $298, $5,397, $5,695 and$6,668, respectively. The average total costs were $49,440 during the follow-upperiod. The four most frequently prescribed medications for AS were prednisonehydrocodone (3.59%), bit/acetaminophen (3.17%), methotrexate sodium (2.79%)and levothyroxine sodium (2.42%). CONCLUSIONS: AS patient demographic andclinical characteristics in the Medicare population were assessed. Study patientswere often diagnosed with comorbid conditions, and had high health care utilization and costs.
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 - WoS: 4
Citation - Scopus: 4
Economic Geography and Human Capital Accumulation in Turkey: Evidence From Micro-Data
(Routledge, 2021) Karahasan, Burhan Can; Bilgel, Fırat
This study examines the impact of market access on human capital accumulation in Turkey. Using individual-level data, the analysis explores the background of human capital accumulation, combining market accessibility, wages and human capital development. Upon the treatment of wages as an endogenous covariate of interest and overtime work as an exogenous source of variation, we find evidence that the impact of market access on human capital development vanishes in ways not predicted by the augmented New Economic Geography set-up for human capital accumulation. Findings confirm that economic policies may be effective in reducing regional variation in human capital endowments.
Citation - WoS: 15
Citation - Scopus: 15
Economic Outcomes in Patients With Chemotherapy-Naive Metastatic Castration-Resistant Prostate Cancer Treated With Enzalutamide or Abiraterone Acetate Plus Prednisone
(Springer, 2020) Lechpammer, Stanislav; Ramaswamy, Krishnan; Wang, Li; Mardekian, Jack; George, Daniel J.; Sandin, Rickard; Schultz, Neil M.; Başer, Onur; Huang, Ahong
Introduction: Prostate cancer (PC) is the second leading cause of cancer death among US men and accounts for considerable healthcare expenditures. We evaluated economic outcomes in men with chemotherapy-naı¨ve metastatic castration-resistant PC (mCRPC) treated with enzalutamide or abiraterone acetate plus prednisone (abiraterone). Methods: We performed a retrospective analysis on 3174 men (18 years or older) utilizing the Veterans Health Administration (VHA) database from 1 April 2014 to 31 March 2018. Men with mCRPC were included if they had at least one pharmacy claim for enzalutamide or abiraterone (ﬁrst claim date = index date) following surgical or medical castration, had no chemotherapy treatment within 12 months prior to the index date, and had continuous VHA enrollment for at least 12 months pre- and post-index date. Men were followed until death, disenrollment, or end of study and were 1:1 propensity score matched (PSM). All-cause and PC-related resource use and costs per patient per month (PPPM) in the 12 months post index were compared between matched cohorts. Results: We identiﬁed 1229 men with mCRPC prescribed enzalutamide and 1945 prescribed abiraterone with mean ages of 74 and 73 years, respectively. After PSM, each cohort had 1160 patients. The enzalutamide cohort had fewer all-cause (2.51 vs 2.86; p\0.0001) and PC-related outpatient visits (0.86 vs 1.03; p\0.0001), with corresponding lower all-cause ($2588 vs $3115; p\0.0001) and PC-related ($1356 vs $1775; p\0.0001) PPPM outpatient costs compared with the abiraterone cohort. Allcause total costs (medical and pharmacy) PPPM ($8085 vs $9092; p = 0.0002) and PC-related total costs PPPM ($6321 vs $7280; p\0.0001) were signiﬁcantly lower in the enzalutamide cohort compared with the abiraterone cohort. Conclusions: Enzalutamide-treated men with chemotherapy-naı ¨ve mCRPC had signiﬁcantly lower resource utilization and healthcare costs compared with abiraterone-treated men. Plain Language Summary: Plain language summary available for this article.
Citation - WoS: 2
Citation - Scopus: 2
Effects of Covid-19 Lockdowns on Social Distancing in Turkey
(Oxford University Press, 2022) Bilgel, Fırat
This paper elucidates the causal effect of lockdowns on social distancing behaviour in Turkey by adopting an augmented synthetic control and a factor-augmented model approach for imputing counterfactuals. By constructing a synthetic control group that reproduces pre-lockdown trajectory of mobility of the treated provinces and that accommodates staggered adoption, the difference between the counterfactual and actual mobility of treated provinces is assessed in the post-lockdown period. The analysis shows that in the short run following the onset of lockdowns, outdoor mobility would have been about 17–53 percentage points higher on average in the absence of lockdowns, depending on social distancing measure. However, residential mobility would have been about 12 percentage points lower in the absence of lockdowns. The findings are corroborated using interactive fixed effects and matrix completion counterfactuals that accommodate staggered adoption and treatment reversals.
Citation - WoS: 4
Citation - Scopus: 4
Effects of Vaccination and the Spatio-Temporal Diffusion of Covid-19 Incidence in Turkey
(John Wiley and Sons Inc, 2022) Bilgel, Fırat; Karahasan, Burhan Can
This study assesses the spatio-temporal impact of vaccination efforts on Covid-19 incidence growth in Turkey. Incorporating geographical features of SARS-CoV-2 transmission, we adopt a spatial Susceptible–Infected–Recovered (SIR) model that serves as a guide of our empirical specification. Using provincial weekly panel data, we estimate a dynamic spatial autoregressive (SAR) model to elucidate the short- and the long-run impact of vaccination on Covid-19 incidence growth after controlling for temporal and spatio-temporal diffusion, testing capacity, social distancing behavior and unobserved space-varying confounders. Results show that vaccination growth reduces Covid-19 incidence growth rate directly and indirectly by creating a positive externality over space. The significant association between vaccination and Covid-19 incidence is robust to a host of spatial weight matrix specifications. Conspicuous spatial and temporal diffusion effects of Covid-19 incidence growth were found across all specifications: the former being a severer threat to the containment of the pandemic than the latter.
Citation - WoS: 10
Citation - Scopus: 12
Elevated White Blood Cell Levels and Thrombotic Events in Patients With Polycythemia Vera: a Real-World Analysis of Veterans Health Administration Data
(Elsevier Inc., 2019) Wang, Li; Parasuraman, Shreekant V.; Sulena Shrestha; Paranagama, Dilan C.; Yu, Jingbo; Scherber, Robyn Marie; Başer, Onur
Background: Patients with polycythemia vera (PV) have a substantial risk of thrombotic events (TEs). The objective of the present analysis was to describe the association between white blood cell (WBC) levels and occurrence of TEs among patients with PV from a large real-world population. Patients and Methods: The present retrospective analysis using Veterans Health Administration claims data (October 1, 2005, to September 30, 2012) evaluated adult patients assigned to 4 WBC count categories (WBC count < 7.0, 7.0-8.4, 8.5 to < 11.0, and ≥ 11.0 × 109/L) to compare the risk of TEs (reference, WBC count, < 7.0 × 109/L group). Analysis was performed using a Cox proportional hazards model, considering WBC status as a time-dependent covariate. Results: Of the 1565 patients with PV included in the present analysis, the WBC count was < 7.0 × 109/L for 428 (27.3%), 7.0 to 8.4 × 109/L for 375 (24.0%), 8.5 to < 11.0 × 109/L for 284 (18.1%), and ≥ 11.0 × 109/L for 478 (30.5%). Of the 1565 patients, 390 (24.9%) had experienced a TE during the study period. The mean follow-up ranged from 3.6 to 4.5 years. Compared with the reference group (WBC count < 7.0 ×109/L), the hazard ratio for TEs was 1.10 (95% confidence interval [CI], 0.82-1.48; P = .5395), 1.47 (95% CI, 1.10-1.96; P = .0097), and 1.87 (95% CI, 1.44-2.43; P < .0001) for patients with a WBC count of 7.0 to 8.4, 8.5 to < 11.0, and ≥ 11.0 ×109/L, respectively. Conclusion: A positive, significant association between an increased WBC count of ≥ 8.5 ×109/L and the occurrence of TEs was observed in patients with PV. The potential thrombogenic role of WBCs in patients with PV supports the continued inclusion of WBC count control in disease management and evaluation of the response to therapy. © 2019 The AuthorsPatients with polycythemia vera (PV) have a substantial risk of thrombotic events (TEs). In the present retrospective analysis using Veterans Health Administration claims data, 25% of 1565 patients experienced a TE during follow-up. We observed a positive, significant association between white blood cell (WBC) counts ≥ 8.5 × 109/L and TE occurrence (reference, WBC count < 7.0 × 109/L), supporting continued inclusion of WBC count control in disease management. © 2019 The Authors
Evaluating Fracture-Related Expenses and Health Care Resource Utilization Among Post-Menopausal Women in the Us Medicaid Population
(2015) Xie, L.; Keshishian, A; Wang, Y.; Başer, Onur
Objectives: Use of potentially inappropriate medications (PIMs) among the elderlyis a serious public health problem because it is intrinsically linked to increasedmorbidity and mortality, causing the high costs to public health systems. Objectivesof this study were to determine the prevalence and predictors of PIM prescribingin elderly inpatients using STOP and START criteria Methods: The prospectiveobservational study was carried at a private tertiary care hospital. Prescriptionsof elderly inpatients aged 60 years and above were collected and analyzed. PIMswere identified with the help of STOP and START criteria. Predictors associatedwith use of PIMs were identified by bivariate and multivariate logistic regressionanalysis. Results: The results were based on data of 60 patients. More than half(56%) were males and 50% were aged between 60–69 years with a mean averageage of 69 years. Mean number of diagnoses and medications were two and nine,respectively. A total of 18 (30%) patients were prescribed with at least 1 PIM accordingSTOP Criteria. Most commonly prescribed PIMs were systemic corticosteroids (29%)followed by theophyline (18%) and betablockers (10%). On multivariate regression,important predictors for PIM prescribing were found to polypharmacy, number ofdiagnoses. Co nclusions: The results show that PIMs prescribing is high in Indianelderly inpatients STOP and START criteria, it is more effective in identifying thePIMs. This study is ongoing and we will present the data upto 250 patents beforethe presentation
Examining Health Care Utilization and Costs Among Atherosclerosis Patients in the Us Veteran Health Administration Population
(2017) Zhang, Q.; Kariburyo, M. T.; Xu, J.; Başer, Onur
...
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: 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.
Citation - WoS: 18
Citation - Scopus: 18
Guns and Homicides: a Multiscale Geographically Weighted Instrumental Variables Approach
(Wiley, 2019) Bilgel, Fırat
This article assesses the locally varying effects of gun ownership levels on total and gun homicide rates in the contiguous United States using cross-sectional county data for the period 2009–2015. Employing a multiscale geographically weighted instrumental variables regression that takes into account spatial nonstationarity in the processes and the endogenous nature of gun ownership levels, estimates show that gun ownership exerts spatially monotonically negative effects on total and gun homicide rates, indicating that there are no counties supporting the “more guns, more crime” hypothesis for these two highly important crime categories. The number of counties in the contiguous United States where the “more guns, less crime” hypothesis is confirmed is limited to at least 1258 counties (44.8% of the sample) with the strongest total homicide-decreasing effects concentrated in southeastern Texas and the deep south. On the other hand, stricter state gun control laws exert spatially monotonically negative effects on gun homicide rates with the strongest effects concentrated in the southern tip of Texas extending toward the deep south.
Citation - WoS: 5
Citation - Scopus: 5
Health Outcomes Among Patients Diagnosed With Schizophrenia in the Us Veterans Health Administration Population Who Transitioned From Once-Monthly To Once-Every Paliperidone Palmitate: an Observational Retrospective Analysis
(Springer, 2019) Khouyr, Antoine El; Wang, Li; Joshi, Kruti; Patel, Charmi; Başer, Onur; Huang, Ahong
There is limited literature on treatment patterns, healthcare resource utilization (HRU), and costs among patients who transition from once-monthly paliperidone palmitate (PP1M) to once-every-3-month paliperidone palmitate (PP3M) in a real-world setting. Hence, this study compared treatment patterns, HRU, and costs 12-month pre- and post-PP3M transition among Veteran’s Health Administration (VHA) patients with schizophrenia.
Citation - WoS: 15
Citation - Scopus: 14
Hepatic Decompensation in Patients With Hiv/Hepatitis B Virus (hbv)/Hepatitis C Virus (hcv) Triple Infection Versus Hiv/Hcv Coinfection and the Effect of Anti-Hbv Nucleos(t)ide Therapy
(2014) Wang, Li; Devine, Scott; Lo Re, Vincent, III; Olufade, Temitope; Başer, Onur
The incidence rate of hepatic decompensation was higher in patients with human immunodeficiency virus (HIV)/hepatitis B virus (HBV)/hepatitis C virus (HCV) triple infection than in those with HIV/HCV coinfection (24.1 vs 10.8 events per 1000 person-years; hazard ratio [HR], 1.89; 95% confidence interval [CI], 1.12–3.18). Compared with HIV/HCVinfected patients, the rate of decompensation was increased among HIV/HBV/HCV-infected patients receiving no anti-HBV therapy (HR, 2.48; 95% CI, 1.37–4.49) but not among those who did receive such therapy (HR, 1.09; 95% CI, .40–2.97)
Citation - WoS: 3
Citation - Scopus: 3
Institutional Quality and Geography of Discontent in the Eu
(John Wiley and Sons Inc, 2023) Pınar, Mehmet; Karahasan, Burhan Can
There has been a significant rise in anti-establishment votes in the European Union (EU). The decline in socio-economic outcomes and migration played an important role in understanding the rising discontent. However, none of the existing studies analysed the effect of socio-economic factors in different institutional settings. Our findings confirm that institutional quality is of paramount importance in explaining the recent rise in populism in the EU, as institutionally developed EU regions are less opposed to EU integration. Remarkably, the effects of socio-economic factors on populist votes vary in different institutional settings. The findings highlight that institutional improvements are vital for the EU perception of less developed and socio-economically isolated EU regions.

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