Central Bank of Turkey

Ankara, Turkey

Central Bank of Turkey

Ankara, Turkey
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Oztaner S.M.,Central Bank of Turkey | Temizel T.T.,Middle East Technical University | Remzi Erdem S.,Baskent University | Ozer M.,Scientific and Technological Research Council of Turkey
IEEE Journal of Biomedical and Health Informatics | Year: 2015

The incorporation of pharmacogenomics information into the drug dosing estimation formulations has been shown to increase the accuracy in drug dosing and decrease the frequency of adverse drug effects in many studies in the literature. In this paper, an estimation framework based on the Bayesian structural equation modeling, which is driven by pharmacogenomics, is proposed. The results show that the model compares favorably with the linear models in terms of prediction and explaining the variations in warfarin dosing. © 2013 IEEE.

Baser O.,University of Michigan | Baser O.,STATinMED Research | Burkan A.,Social Security Institution | Baser E.,Central Bank of Turkey | And 3 more authors.
International Journal of Rheumatology | Year: 2013

Objectives. To explore health care costs associated with ankylosing spondylitis (AS) in Turkey. Methods. Research-identified data from a system that processes claims for all Turkish health insurance funds were analyzed. Adult prevalent and incident AS patients with two AS visits at least 60 days apart, identified between June 1, 2010 and December 31, 2010, with at least 1 year of continuous health plan enrollment for the baseline and follow-up years were included in the study. Pharmacy, outpatient, and inpatient claims were compiled over the study period for the selected patients. Generalized linear models were used to estimate the expected annual costs, controlling for baseline demographic and clinical characteristics. Results. A total of 2.986 patients were identified, of which 603 were incident cases and 2.383 prevalent cases. The mean ages were 39 and 41 years, respectively, and 44% and 38% were women for incident and prevalent cases. Prevalent patients had higher comorbidity scores (5.01 versus 2.24, P < 0.001) and were more likely to be prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) (77% versus 72%, P < 0.001) or biologics (35% versus 8%, P < 0.006) relative to incident patients. Seventy-seven percent of prevalent patients were prescribed NSAIDs, followed by biologic and disease-modifying antirheumatic drugs (DMARDs). Total annual medical costs for incident AS patients were 2.253 and 4.233 for prevalent patients. Pharmacy costs accounted for a significant portion of total costs (88% for prevalent patient, 77% for incident patient), followed by physician office visit costs. Prior comorbidities and treatment type also significantly contributed to overall costs. Conclusion. Annual expenditures for AS patients in Turkey were comparable relative to European countries. Pharmaceutical expenditures cover a significant portion of the overall costs. Comparative effectiveness studies are necessary to further decrease health care costs of AS treatment. © 2013 Onur Baser et al.

Baser O.,University of Michigan | Baser O.,STATinMED Research | Burkan A.,Social Security Institution | Baser E.,Central Bank of Turkey | And 3 more authors.
Health Policy | Year: 2013

Objective: Encourage quality improvements and assess high expenditures for patients with coronary artery bypass graft (CABG) surgery and hospital quality in Turkey. Methods: Using the Turkish National Health Insurance Database (2009-2011), CABG surgery patients were identified using International Classification of Diseases Tenth Revision Clinical Modification codes. High-cost cardiac surgery patients had annual healthcare costs in the top 20% post-surgery. The empirical Bayes approach was used to combine mortality rates with hospital volume for quality index, weighing observed mortality according to estimation reliability, with the remaining weight placed on hospital volume. The relationship between hospital quality and high-cost payments was assessed using chi-square tests. Results: Total annual healthcare payments for 20,126 identified CABG patients were approximately €70 million. High-cost patients incurred 31% of the total expenditures. Although disease severity did not differ for patients across hospitals, those in the lowest quartile, in terms of quality, cared for 25% of high-costs surgery patients, compared with only 18% in the highest quality hospitals (p<0.0001) €4M in associated cost savings was calculated for patients shifting from low- to high-quality hospitals. Conclusions: Results imply that hospital quality improvements can reduce costs and improve morbidity and mortality rates in Turkey. © 2012 Elsevier Ireland Ltd.

Baser O.,University of Michigan | Baser O.,STATinMED Research | Burkan A.,Social Security Institution | Baser E.,Central Bank of Turkey | And 3 more authors.
Rheumatology International | Year: 2013

This study aimed to estimate and identify determinants of direct medical costs associated with rheumatoid arthritis (RA) in Turkey using nationwide real-world data. Using the Turkish National Health Insurance Database (2009-2011), RA patients (ages 18-99) were identified using International Classification of Disease Tenth Revision Clinical Modification (ICD-10-CM) codes. Patients were required to have two RA diagnoses at least 60 days apart and were grouped as prevalent and incident cases. The date of the first RA claim was identified for each patient and designated as the index date. Total healthcare costs were examined over the 12-month period following the index date. Descriptive and multivariate analyses are provided. Generalized linear models were used to calculate expected annual costs for incident and prevalent RA patients after controlling for age, gender, region, comorbid conditions and medication. A total of 2,613 patients met all inclusion criteria (693 incident; 1,920 prevalent patients). Prevalent patients were older, less likely to reside in the Marmara region, had higher comorbidity index scores and were more likely to use non-steroidal anti-inflammatory drugs, biologics and disease-modifying anti-rheumatic drugs relative to incident patients. Average direct annual costs were €2,000 [(€1,750, €2,247) 95 % CI] for incident cases and €2,385 [(€2,224, €2,545) 95 % CI] for prevalent cases, most due to pharmacy costs (73 % for incident cases, 60 % for prevalent cases). For incident and prevalent cases, a significant portion of inpatient and outpatient costs were due to physician costs (31 % for incident cases, 40 % for prevalent cases). Although the costs were not significantly different in terms of age or region, prior comorbid conditions and medication use significantly affected the cost estimation. RA total annual costs were found to be lower in Turkey, relative to estimates in Europe. The significant portion of the annual costs was due to pharmaceutical expenditures. Comparative effectiveness analysis may be useful to decrease RA-related pharmacy costs. © 2013 Springer-Verlag Berlin Heidelberg.

Baltagi B.H.,Syracuse University | Baskaya Y.S.,Central Bank of Turkey | Hulagu T.,Central Bank of Turkey
Papers in Regional Science | Year: 2013

This paper estimates wage curves for formal and informal workers using a rich individual level data for Turkey over the period 2005-2009. The wage curve is an empirical regularity describing a negative relationship between regional unemployment rates and individuals' real wages. While this relationship has been well documented for a number of countries including Turkey, less attention has focused on how this relationship differs for informal versus formal employment. This is of utmost importance for less developed countries where informal employment plays a significant role in the economy. Using the Turkish Household Labour Force Survey observed over 26 NUTS 2 regions, we find that real hourly wages of informal workers in Turkey are more sensitive to variations in regional unemployment rates than wages of formal workers. This is true for all workers as well as for different gender and age groups. © 2013 The Author(s). Papers in Regional Science © 2013 RSAI.

Ozorhan M.O.,Central Bank of Turkey | Cicekli N.K.,Middle East Technical University
Computer and Information Sciences II - 26th International Symposium on Computer and Information Sciences, ISCIS 2011 | Year: 2012

This paper discusses automated methods to achieve web service advertisement and discovery, and presents efficient search and matching techniques based on OWL-S. The service discovery and matchmaking is performed via a centralized peer-to-peer web service repository. The repository has the ability to run on a software cloud, which improves the availability and scalability of the service discovery. An OWL-S based unified ontology - Suggested Upper Merged Ontology - is used in web service annotation. User-agents generate query specification using the system ontology, to provide semantic unification between the client and the system during service discovery. Query matching is performed via complex Hilbert Spaces composed of conceptual planes and categorical similarities for each web service. © 2012 Springer-Verlag London Limited.

Aizenman J.,University of Southern California | Binici M.,Central Bank of Turkey | Hutchison M.,UCSC
Oxford Review of Economic Policy | Year: 2013

This paper investigates the impact of credit rating changes on the sovereign spreads in the European Union and investigates the macro and financial factors that account for the time-varying effects of a given credit rating change. We find that changes of ratings are informative, economically important, and highly statistically significant in panel models, even after controlling for a host of domestic and global fundamental factors and investigating various functional forms, time and country groupings, and dynamic structures. Dynamic panel model estimates indicate that a credit rating upgrade decreases credit default swap (CDS) spreads by about 45 basis points, on average, for European Union (EU) countries. However, the association between credit rating changes and spreads shifted markedly between the pre-crisis and crisis periods. European countries had quite similar CDS responses to credit rating changes during the pre-crisis period, but large differences emerged during the crisis period between the now highly sensitive GIIPS group (Greece, Italy, Ireland, Portugal, Spain) and other European country groupings (EU and euro area excluding GIIPS, and the non-EU area). We also find a complicated non-linear pattern dependent on the level of the credit rating. The results are robust to the inclusion of credit 'outlook' or 'watch' signals by credit rating agencies. In addition, contagion from rating downgrades in GIIPS to other euro countries is not evident once own-country credit rating changes are taken into account. © The Authors 2013. Published by Oxford University Press.

Orhan M.,Fatih University | Koksal B.,Central Bank of Turkey
Expert Systems with Applications | Year: 2012

This study is an attempt to compare a comprehensive list of GARCH models in quantifying risks of VaR under stress times. We gather data of stock market indices from both emerging (Brazil and Turkey) and developed (Germany and the USA) markets, over the period of global financial crisis and make use of numerous GARCH specifications to return VaR values. Then we compare the assessments of VaR with the realized returns by Kupiec and Christoffersen Tests. Besides, we calculate Quadratic Losses to evaluate the GARCH specifications in calculating VaR. The results reveal that the ARCH specification is the best performer followed by GARCH(1, 1) and the Student's t distribution is slightly better than the Normal. The other outcome of the paper is that the worst performers are Non-Linear Power GARCH and Non-Linear Power GARCH with a shift. All GARCH estimations are carried out with STATA that uses the Maximum Likelihood method of estimation. © 2011 Elsevier Ltd. All rights reserved.

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