Department of Statistics, Article

Search within this collection:


Entity Type
Publication (283)

Has File(s)
No (230)
Yes (53)

Kalafat, Erkan (41)
Purutçuoğlu Gazi, Vilda (28)
İlk Dağ, Özlem (24)
Khalil, Asma (24)
Yozgatlıgil, Ceylan (21)

Statistics and Probability (45)
Statistics, Probability and Uncertainty (29)
General Medicine (19)
Obstetrics and Gynaecology (18)
Applied Mathematics (12)

Date Issued
1990 - 1999 (7)
2000 - 2009 (56)
2010 - 2019 (157)
2020 - 2022 (63)

Item Type
Journal Article (215)
Article (1)
Conference Paper (1)

Recent Submissions

Adverse neonatal outcome in twin pregnancy complicated by small-for-gestational age: twin vs singleton reference charts
Briffa, C.; Di Fabrizio, C.; Kalafat, Erkan; Giorgione, V.; Bhate, R.; Huddy, C.; Richards, J.; Shetty, S.; Khalil, A. (2022-03-01)
Objective The use of twin-specific vs singleton growth charts in the assessment of twin pregnancy has been controversial. The aim of this study was to assess whether a diagnosis of small-for-gestational age (SGA) made usin...
Clinical severity of SARS-CoV-2 infection among vaccinated and unvaccinated pregnancies during the Omicron wave
Birol Ilter, P.; Prasad, S.; Berkkan, M.; Mutlu, M. A.; Tekin, A. B.; Celik, E.; Ata, B.; Turgal, M.; Yildiz, S.; Turkgeldi, E.; O'Brien, P.; von Dadelszen, P.; Magee, L. A.; Kalafat, Erkan; Tug, N.; Khalil, A. (2022-03-01)
Should angiogenic markers be included in diagnostic criteria of superimposed pre-eclampsia in women with chronic hypertension?
Binder, J.; Kalafat, Erkan; Palmrich, P.; Pateisky, P.; Khalil, A. (2022-02-01)
Objective Although the most recent guidance from the International Society for the Study of Hypertension in Pregnancy (ISSHP) has highlighted the role of angiogenic marker assessment in the diagnosis of pre-eclampsia (PE) ...
The Comparison of Fixed and Flexible Progestin Primed Ovarian Stimulation on Mature Oocyte Yield in Women at Risk of Premature Ovarian Insufficiency
Kalafat, Erkan; Dizdar, Merve; Turkgeldi, Engin; Yildiz, Sule; Keles, Ipek; Ata, Baris (2022-02-01)
While gonadotrophin releasing hormone (GnRH) antagonists have been the standard of pituitary suppression during ovarian stimulation for ART, progestin primed ovarian stimulation (PPOS) has emerged as an alternative. Proges...
Do live birth rate and obstetric outcomes vary between immediate and delayed embryo transfers following freeze-all cycles?
Yildiz, Sule; Turkgeldi, Engin; Kalafat, Erkan; Keles, Ipek; Gokyer, Dilan; Ata, Baris (2021-12-01)
Research question: Do live birth rates (LBR), obstetric and perinatal outcomes vary between women who underwent frozen embryo transfer (ET) in the immediately subsequent menstrual cycle, and with those who underwent delaye...
Personalized reference intervals – statistical approaches and considerations
Coskun, Abdurrahman; Sandberg, Sverre; Unsal, Ibrahim; Gökalp Yavuz, Fulya; Cavusoglu, Coskun; Serteser, Mustafa; Kılercık, Meltem; Aasne K , Aarsand (2021-12-01)
For many measurands, physicians depend on population-based reference intervals (popRI), when assessing laboratory test results. The availability of personalized reference intervals (prRI) may provide a means to improve the...
COVID-19 vaccination in pregnancy-number needed to vaccinate to avoid harm
Magee, Laura A; von Dadelszen, Peter; Kalafat, Erkan; Duncan, Emma L; O'Brien, Pat; Morris, Edward; Heath, Paul; Khalil, Asma (2021-12-01)
Short-term outcomes of pregnant women with convalescent COVID-19 and factors associated with false-negative polymerase chain reaction test: A prospective cohort study.
Sahin, Orhan; Yildirmak, Taner; Karacalar, Serap; Aydin, Emine; Ciftci, Mehmet Ali; Bagci, Helin; Yildirim, Sukran; Emeklioglu, Cagdas; Balci, Burcu Gulsah; Genc, Simten; Cingillioglu, Basak; Mihmanli, Veli; Khalil, Asma; Kalafat, Erkan (2021-11-01)
Aim To evaluate the clinical factors associated with false-negative RT-PCR results and to report the outcome of a cohort of pregnant women with COVID-19. Methods This cohort study was conducted in a tertiary referral pande...
A new definition of recurrent implantation failure on the basis of anticipated blastocyst aneuploidy rates across female age.
Ata, Baris; Kalafat, Erkan; Somigliana, Edgardo (2021-11-01)
Objective: To present a definition of recurrent implantation failure that accounts for the effects of female age and anticipated blastocyst euploidy rates on cumulative implantation rates. Design: Mathematical modeling. Se...
An internally validated prediction model for critical COVID-19 infection and intensive care unit admission in symptomatic pregnant women
Kalafat, Erkan; et. al. (2021-09-25)
Background: Pregnant women are at an increased risk of mortality and morbidity owing to COVID-19. Many studies have reported on the association of COVID-19 with pregnancy-specific adverse outcomes, but prediction models ut...
Prognostic value of angiogenic markers in pregnant women with chronic hypertension
Binder, Julia; Palmrich, Pilar; Kalafat, Erkan; Pateisky, Petra; Oeztuerk, Ebru; Mittelberger, Johanna; Khalil, Asma (2021-09-07)
Women with chronic hypertension face a 5-to 6-fold increased risk of developing preeclampsia compared with normotensive women. Angiogenic markers, especially soluble fms-like kinase 1 (sFlt-1) and placental growth factor (...
Factors associated with livebirth in couples undergoing their first in vitro fertilization cycle: An internally validated prediction model
Kalafat, Erkan; Benlioglu, Can; Gokce, Ali; ŞÜKÜR, YAVUZ EMRE; ÖZMEN, BATUHAN; SÖNMEZER, MURAT; ATABEKOĞLU, CEM SOMER; Aytac, Rusen; BERKER, BÜLENT (2021-09-01)
Objective: The aim of the study is to create a new model to predict successful outcome in assisted reproductive techniques.
Angiogenic markers and their longitudinal change for predicting adverse outcomes in pregnant women with chronic hypertension
Binder, Julia; Kalafat, Erkan; Palmrich, Pilar; Pateisky, Petra; Khalil, Asma (2021-09-01)
Background: Women with chronic hypertension are at increased risk for adverse maternal and perinatal outcomes. Maternal serum angiogenic markers, such as soluble fms-like tyrosine kinase 1 and placental growth factor, can ...
SARS-CoV-2 vaccination in pregnancy: a unique opportunity for equity
Kalafat, Erkan; Magee, Laura A.; von Dadelszen, Peter; O'Brien, Pat; Khalil, Asma (2021-09-01)
Analysis of correlated circular and extremal data with a flexible cylindrical distribution
Kalaylıoğlu Akyıldız, Zeynep Işıl (2021-08-01)
In this article, we introduce a flexible cylindrical distribution for modeling and analysis of dependent extremal and directional observations. The distribution can be used to investigate the connection between two related...
An optimal stopping problem for spectrally negative Markov additive processes
Çağlar, Mine; Kyprianou, Andreas; Vardar Acar, Ceren (2021-07-01)
Previous authors have considered optimal stopping problems driven by the running maximum of a spectrally negative Lévy process as well as of a one-dimensional diffusion; see e.g. Kyprianou and Ott (2014); Ott (2014); Ott (...
Are live birth rate and obstetric outcomes different between immediate and delayed embryo transfers following a freeze-all cycle? A retrospective study combined with a meta-analysis
Yildiz, S.; Turkgeldi, E.; Kalafat, Erkan; Gokyer, D.; Keles, I.; Ata, B. (2021-07-01)
The impacts of COVID-19 lockdown on PM10 and SO2 concentrations and association with human mobility across Turkey
Orak, Nur Hanife; Özdemir, Ozancan (2021-06-01)
The SARS-CoV-2 virus pandemic (COVID-19) has caused 2.25 million deaths worldwide by February 3, 2021 (JHU, 2021) and still causing severe health and economic disruptions with increasing rates. This study investigates the ...
Analysis of Confidence Levels and Application Success Rates in Simulator-Based Dental Anesthesia Education Among Undergraduate Dental Students
Vural, Çağıl; Bozkurt, Poyzan; Vardar Acar, Ceren; Üçok, Cahit (2021-06-01)
Purpose: We investigated the confidence levels of undergraduate dental students who used dental anesthesia simulators and patient reports of undergraduate dental students' confidence levels in delivering anesthesia injecti...
Living at-risk in a multi-hazard country
Başbuğ Erkan, Berna Burçak (2021-06-01)
Citation Formats