1. Clinic of General Surgery, Ankara City Hospital, Ankara, Turkey

2. Department of General Surgery, Karadeniz Technical University Faculty of Medicine, Trabzon, Turkey

3. Clinic of Gastroenterological Surgery, Kartal Koşuyolu High Speciality Educational And Research Hospital, Istanbul, Turkey

4. Department of Biostatics, Hacettepe University Faculty of Medicine, Ankara, Turkey

5. Clinic of General Surgery, Ankara Numune Training and Research Hospital, Ankara, Turkey