Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1926

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Now showing 1 - 20 of 62

Citation - WoS: 8
Citation - Scopus: 9
A Value-Adding Approach To Reliability Under Preventive Maintenance Costs and Its Applications
(2014) Dubey, Rameshwar; Kılıç, Erdem; Ali, Sadia Samar; Weber, Gerhard Wilhelm
No equipment (system) can be perfectly reliable in spite of the utmost care and best efforts on the part of the designer, decision-maker and manufacturer. The two sides of maintenance are corrective and preventive maintenance. It is generally assumed that a preventive maintenance action is less costly than a repair maintenance action. We examine this proposition in detail on the basis of a failure-time model that relates conformance quality to reliability. Illustratively, we present reliability in the context of contracts with asymmetric information. The model shows how to overcome information rents through price distortions and quantity rationing. The paper ends with a conclusion and an outlook to future studies.
Citation - WoS: 18
Citation - Scopus: 18
Adding Rapid-Acting Insulin or Glp-1 Receptor Agonist To Basal Insulin: Outcomes in a Community Setting
(2015) Dalal, Mehul R; DiGenio, Andres; Xie, Lin; Başer, Onur
To evaluate real-world outcomes in patients with type 2 diabetes mellitus (T2DM)receiving basal insulin, who initiate add-on therapy with a rapid-acting insulin (RAI) or aglucagon-like peptide 1 (GLP-1) receptor agonist.Data were extracted retrospectively from a U.S. health claims database. Adults withT2DM on basal insulin who added an RAI (basal+RAI) or GLP-1 receptor agonist (basal+GLP-1) were included. Propensity score matching (1 up to 3 ratio) was used to control for differencesin baseline demographics, clinical characteristics, and health resource utilization. Endpointsincluded prevalence of hypoglycemia, pancreatic events, all-cause and diabetes-relatedresource utilization, and costs at 1 year follow-up. Overall, 6,718 matched patients were included: 5,013 basal+RAI and 1,705basal+GLP1. Patients in both groups experienced a similar proportion of any hypoglycemicevent (P = .4079). Hypoglycemic events leading to hospitalization were higher in the basal+RAIcohort (2.7% vs. 1.8%; P = .0444). The basal+GLP-1 cohort experienced fewer all-cause(13.55% vs. 18.61%; P<.0001) and diabetes-related hospitalizations (11.79% vs. 15.68%;P<.0001). The basal+GLP-1 cohort had lower total all-cause health care costs ($18,413 vs.$20,821; P = .0002), but similar diabetes-related costs ($9,134 vs. $8,985; P<.0001) comparedwith the basal+RAI cohort. Add-on therapy with a GLP-1 receptor agonist in T2DM patients receiving basalinsulin was associated with fewer hospitalizations and lower total all-cause costs compared withadd-on therapy using a RAI, and could be considered an alternative to a RAI in certain patientswith T2DM, who do not achieve effective glycemic control with basal insulin.
Citation - WoS: 44
Citation - Scopus: 67
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 - Scopus: 8
An Empirical Analysis of Financial Fair-Play: the Case of Russian Premier League
(Pensoft Publishers, 2020) Özaydın, Selçuk
The real impact of financial fair play (FFP) came along with the break-even rule which prevents clubs from over-spending through a variety of sanctions. As UEFA limited clubs’ expenses with their incomes, the transfer market took a hit. This paper demonstrates the impact of FFP on Russian Premier League teams’ transfer activity, examines how transfers’ demography and career profiles changed and investigates the changes in competitive balance after break-even. A regression discontinuity design is conducted in order to estimate the policy impact. The empirical results suggest that Russian clubs have been severely affected by break-even in terms of transfer expenditure and balance and started to transfer more U21 players and players from lesser leagues of the world. Furthermore, competitive balance in the Russian Premier League deteriorated in favor of the giants in the league as a result of break-even.
Citation - WoS: 5
Citation - Scopus: 7
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 - Scopus: 5
Asymmetric Effects of Eu Cohesion Policy on Eu Regional Growth: the Role of Macroeconomic Uncertainty
(Elsevier B.V., 2024) Pınar, Mehmet; Karahasan, Burhan Can
Cohesion policy and the EU funds have been key elements for territorial integration in Europe. Evidence shows that EU funds support the growth performance of regions. However, less has been discussed about the potential impact of macroeconomic uncertainty on the effectiveness of EU funds. Our analyses confirm that EU funds are important in understanding regional economic growth differences. However, the extent of macroeconomic uncertainty decreases the effectiveness of the EU funds. Our results are robust in including local controls, non-linearity of the EU funds’ effect, different EU fund categories, and regional heterogeneity in the EU. © 2024 The Authors
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.
Classifying the European Football Leagues by Using Balance-Performance Matrix
(Pamukkale University, 2021) Özaydın, Selçuk Mustafa
European football has transformed over the last two decades both financially and athletically. Although the aggregate revenue generated by the European football increases, some leagues grew richer than the others. The inequality in the distribution of revenue caused the talents to accumulate in the Big 5 leagues and left the others with no chance to compete. Especially after the introduction of Financial Fair Play, teams from other leagues became in desperate need of transfer income which accelerated the accumulation of talent. This paper proposes a matrix, the Balance-Performance Matrix, for classifying leagues with respect to their transfer balance and sportive performance. As the results of the matrix illustrate, some leagues indeed became suppliers for the Big 5 and they have lost their competitive edge whereas some are still competing despite losing their best talents.
Citation - WoS: 40
Citation - Scopus: 38
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: 15
Citation - Scopus: 18
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: 9
Citation - Scopus: 10
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.
Citation - WoS: 1
Citation - Scopus: 2
Determinants of Turkish Female Labour Force Participation: an Analysis With Manufacturing Firm-Level Data
(Taylor & Francis, 2020) Karamollaoğlu, Nazlı; Soybilgen, Barış
Compared to other developing countries, Turkey has a very low female labour participation rate. Previous studies usually focus on the labour supply side of female employment. Unlike the previous literature, this paper investigates firm-level determinants of female employment in manufacturing firms using a unique micro data set constructed using different sources. After controlling for geographical variation, firm, and industry-specific factors, our results show that larger firms, exporter firms, firms with higher part-time worker ratio, and foreign-owned firms have higher female employment rate whereas younger firms, firms with higher labour productivity, and firms with long working hours have lower female employment rate.
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: 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: 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 - Scopus: 4
Economic Impact and Complications of Treated and Untreated Hepatitis C Virus Patients in Turkey
(2015) Altinbaş, Akif; Baser E; Kariburyo, F; Başer, Onur
Background: According to the Turkish Ministry of Health’s guidelines,standard double therapy, a combination of pegylated interferon-alphaand ribavirin, was the only treatment option for patients withhepatitis C virus (HCV) infection until the end of 2011. Objective: Theprimary objective was to compare risk-adjusted clinical and economicoutcomes between treated and untreated patients with HCV infection.Methods: Patients with HCV infection were identified from theTurkish National Health Insurance Database (2009–2011) using International Classification of Diseases, 10th Revision, Clinical Modification codes.The first prescription date was designated as the index date. Mortalityand hepatocellular carcinoma (HCC) rates and health care costs oftreated and untreated patients were compared using propensity scorematching. Baseline demographic and clinical factors were controlledin the models. Subgroup analysis was conducted for patient groupswith and without a cirrhosis diagnosis. Results: Out of 12,990 patientsincluded in the study, 1,583 were treated for HCV infection. Out of2,467 patients who had a cirrhosis diagnosis, 231 were treated,whereas out of 10,523 patients without cirrhosis, 1,352 patients weretreated. Treated patients were younger, less likely to be diagnosedwith comorbid conditions, and less likely to reside in Central orEastern Anatolia. After adjusting for baseline demographic andclinical factors, mortality (2.27% vs. 5.31%; P o 0.001) and HCC rates(0.69% vs. 1.96%; P o 0.001) were found to be lower for treatedpatients. Differences were more significant among patients diagnosedwith cirrhosis. Treated patients incurred higher risk-adjusted annualcosts (€6172 vs. €1680; P o 0.001), mainly because of pharmaceuticalcosts (€4918 vs. €583; P o 0.001). Conclusions: HCV infection treatment, although costly, significantly reduces mortality and HCC ratesin Turkey.
Citation - WoS: 13
Citation - Scopus: 14
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: 3
Citation - Scopus: 3
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.