Hakan Şıvgın

Dr. Hakan Şıvgın

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 August 2021 in Acta Microbiologica Et Immunologica Hungarica
Verified
Journal Article
Closed access
PDF file
MCMeryem Cetin
Meryem Cetin
PBPervin Ozlem Balci
Pervin Ozlem Balci
HŞHakan Şıvgın
Hakan Şıvgın
SCSirin Cetin
Sirin Cetin
AUAyse Ulgen
Ayse Ulgen
WLWentian Li
Wentian Li
The emergence of new SARS-CoV-2 variants is a challenge to the control of this pandemic. It is therefore important to collect and to analyze data related to the infection caused by different variants. We have obtained more than 3,700 COVID-19 patients between April 2020 and March 2021 from Tokat, Turkey (roughly 3,100 outpatients and close to 600 inpatients) where about 30% were infected with Alpha variant (B.1.1.7). Descriptive statistics was used to characterize different subgroups. Both logistic regression and cause-specific Cox survival analysis of competing-risk was run on inpatients, to examine the impact of Alpha variant on hospitalization, on mortality and on other factors. We observed that the Alpha variant is over-represented in inpatients than outpatients so infection by Alpha variant increases the chance for hospitalization. The impact of Alpha variant on mortality seems to depend on the patient's age. For patients under age of 70, the case-fatality-rate was 0.84% (5.3%) for patients without (with) Alpha variant (Fisher's test P-value = 2.4 × 10−10). For patients above age of 70, the trend is opposite: the case-fatality-rate is 31.5% (13.6%) for patients without (with) Alpha variant (Fisher's test P-value = 0.0016). The two opposite trends would cancel each other, making other analyses such as cause-specific Cox regression and logistic regression non-significant. The Alpha variant increases the risk for hospitalization, increases the case-fatality-rate for lower age group, and decreases the case-fatality-rate for the upper age group. If the increase of case-fatality-rate in not the most senior group holds true, it should provide useful information for a vaccination planning to counter the impact of Alpha variants.

24 May 2021 in Journal of Contemporary Medicine
Verified
Journal Article
Closed access
PDF file
ŞCŞirin Cetin
Şirin Cetin
AUAyse Ulgen
Ayse Ulgen
HŞHakan Şıvgın
Hakan Şıvgın
WLWentian Li
Wentian Li
Knowing the typical length of hospital stay of COVID-19 patients and which factors affecting the stay time is important for hospital management. 3184 COVID-19 patients from the Tokat State Hospital collected from were examined on arrival to the hospital and were either treated as inpatients, or as outpatients. By using simple, conditional and cause-specific Cox proportional-hazard regressions for competing risk, we examined factors impacting hospital stay time, both overall and by taking into account patient’s age or survival status and contribution from a factor to the rate of event of mortality, and to the event of discharge. Surviving ICU patients have longer hospital stay time than non-surviving ICU patients, which is longer than non-ICU patients. Older age is correlated with a longer hospital stay. Increased C-reactive protein (CRP), decreased hemoglobin (HGB) and calcium levels are associated with longer hospital stay, independent from the contribution from surviving status. Almost all factors we collected contribute to a faster/slower mortality or discharge rate. We also observed that glucose is more important than HbA1C or diabetes status in its influence on hospital stay time. This information could be used for a better hospital bed management.

8 October 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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AKAli Kirik
Ali Kirik
Hilmi Erdem SumbulHilmi Erdem Sumbul
Hilmi Erdem Sumbul
Nizameddin KocaNizameddin Koca
Nizameddin Koca
TKTurkan Pasali Kilit
Turkan Pasali Kilit
SSsibel demiral sezer
sibel demiral sezer
TDTeoman Doğru
Teoman Doğru
Introduction: Metabolic dysfunction-associated steatotic liver disease (MASLD) prevalence data in Türkiye is limited. We aimed to determine the nationwide prevalence of MASLD and advanced hepatic fibrosis risk in subjects with cardiometabolic risk factors (CMRF). Despite recent international consensus redefining fatty liver disease terminology, no nationwide MASLD study has been reported in Türkiye. Methods: This cross-sectional study included 14,371 adults with ≥1 CMRF from 44 centers across 31 cities. MASLD was diagnosed using liver ultrasonography plus cardiometabolic criteria. Advanced fibrosis risk was assessed by fibrosis-4 (FIB-4) score (≥1.3 for ≤65 years; ≥2.0 for >65 years). Logistic regression was used to identify independent predictors of high FIB-4. Results: A total of 61.4% of participants were women, the mean age was 51.3 ± 14.4 years, and the mean BMI was 31.4 ± 6.0 kg/m2. MASLD prevalence was 75.7% (n = 10,873), rising with the number of CMRFs (56.5% with one factor vs. 83.4% with all). The prevalence of high FIB-4 scores was 12.0% overall, being lower in MASLD patients than non-MASLD patients (11.2% vs. 14.4%, p < 0.001). FIB-4 scores decreased with increasing BMI (28.1% underweight vs. 8.7% class III obesity). Male sex, T2DM, and hypertension independently predicted high FIB-4 scores, while smoking, higher BMI, and MASLD were inversely associated. Conclusions: Three-quarters of Turkish adults with CMRF have MASLD. Standard FIB-4 thresholds may underestimate fibrosis risk in obese and smoking populations, underscoring the need for adjusted cut-offs or alternative tools. This study is the first to provide nationwide MASLD prevalence data in Türkiye.

28 August 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
ŞCŞirin Cetin
Şirin Cetin
AUAyse Ulgen
Ayse Ulgen
OPOzge Pasin
Ozge Pasin
HŞHakan Şıvgın
Hakan Şıvgın
MCMeryem Cetin
Meryem Cetin
Background/Objectives: Gallstone disease, a prevalent and costly digestive system disorder, is influenced by multifactorial risk factors, some of which may predispose to malignancy. This study aims to evaluate the association between gallstone disease and malignancy using advanced machine learning (ML) algorithms. Methods: A dataset comprising approximately 1000 patients was analyzed, employing six ML methods: random forests (RFs), support vector machines (SVMs), multi-layer perceptron (MLP), MLP with PyTorch 2.3.1 (MLP_PT), naive Bayes (NB), and Tabular Prior-data Fitted Network (TabPFN). Comparative performance was assessed using Pearson correlation, sensitivity, specificity, Kappa, receiver operating characteristic (ROC), area under curve (AUC), and accuracy metrics. Results: Our results revealed that age, body mass index (BMI), and history of HRT were the most significant predictors of malignancy. Among the ML models, TabPFN emerged as the most effective, achieving superior performance across multiple evaluation criteria. Conclusions: This study highlights the potential of leveraging cutting-edge ML methodologies to uncover complex relationships in clinical datasets, offering a novel perspective on gallstone-related malignancy. By identifying critical risk factors and demonstrating the efficacy of TabPFN, this research provides actionable insights for predictive modeling and personalized patient management in clinical practice.

21 May 2021 in Journal of Health Sciences and Medicine
Verified
Journal Article
Open access
PDF file
AUAyse Ulgen
Ayse Ulgen
ŞCŞirin Cetin
Şirin Cetin
PBPervin Özlem Balci
Pervin Özlem Balci
HŞHakan Şıvgın
Hakan Şıvgın
SŞSevdiye Şivgin
Sevdiye Şivgin
WLWentian Li
Wentian Li
Aim: The decision of admitting COVID-19 patients as inpatients is mostlydetermined by chest X-ray based diagnosis of pneumonia severity. However, prognosis of inpatients may diverge into two groups, onegroup of inpatients did not survive while another group did. Material and Method: More than 100 COVID-19 outpatients are collected from Tokat, Turkey in three categories: outpatients, surviving inpatients, and deceased inpatients. Their blood test profiles are analyzed and compared bydimension reduction techniques and classic statistical tests. Results: We observe that surviving inpatients share a common blood test profilewith the outpatients, whereas non-surviving inpatients aredistinctively different. The non-surviving inpatients areon average older. Among patients older than certain age, non-survivinginpatients have higher neutrophil level, lower lymphocyte level(thus higher neutrophil/lymphocyte ratio), lower calcium level,higher C-reactive-protein, sodium, whole blood cell level, andlower hemoglobin level, than the surviving patients (whether these are inpatients or outpatients). Conclusion: Surviving status is more important than in- and out-patient statusin a patient’s cluster membership based on blood test profile. This result suggests a plan to use both X-ray diagnosis and blood testresults as a criterion to admit COVID-19 inpatients.

27 March 2023 in Journal of Health Sciences and Medicine
Verified
Journal Article
Open access
PDF file
HŞHakan Şıvgın
Hakan Şıvgın
MBMustafa Sami Bostan
Mustafa Sami Bostan
Aim: We aimed to investigate correlation between the effects of age, sex, disease, pathologic diagnosis, parathyroid autotransplantation, presence of parathyroid in the pathology specimen and clinicopathological variables and thyroid volume, postoperative hypocalcemia after bilateral total thyroidectomy. Material and Method: A retrospective study planned in tertiary university hospital on patients undergone bilateral total thyroidectomy and neck dissection when necessary surgery for thyroid pathologies. Minimum calcium values in the postoperative period were recorded as transient or permanent hypocalcemia. The cases were statistically analyzed for the relationship between the volume of the thyroid gland removed and hypocalcemia. The effects of sex, pathological diagnosis, preoperative hyperthyroidism, anatomical retrosternal extension, number of parathyroid glands seen and preserved intraoperatively, parathyroid gland autoimplantation, parathyroid gland removal in the pathological specimen, nerve monitoring, bilateral total thyroidectomy and central and lateral neck dissection were analyzed for postoperative hypocalcemia. Results: Totally 763 patients were included in the study. The mean age of the patients was 50.6 years (SD:12.8) and the sex of 575 (75.4%) patients was female. Hypocalcemia was more common in women than in men (31% vs 17%; p