Ethics approval and consent to participate: The study was approved by the Ethics Committee of Istanbul University–Cerrahpaşa (83045809-604.01.02). The project did not receive funding. This study was conducted in accordance with the Declaration of Helsinki on Ethical Principles. Since this was a retrospective database study, informed patient consent was not required.
Consent for publication: Not applicable
Availability of data and materials: All data generated or analysed during this study are included in this published article and its supplementary information files.
Competing interests: Koray Tascilar has served as a speaker for Gilead. Gulen Hatemi has received grant/research support from Celgene and has served as a speaker for AbbVie, Celgene, Novartis, and UCB Pharma. No other disclosures were reported.
Funding: This study did not receive funding.
Authors’ Contributions: G.H., V.H., C.B., S.A., U.K., and S.S.K contributed to the research idea and study design. S.N.E., K.T., H.B., C.B., B.T., S.A., O.P., C.A., D.T., E.S., T.Y.I., N.A.K., E.B., E.T., S.Y.C., E.C.B., S.S.K., U.K., O.C.I., S.U., H.E.O., V.H., and G.H. contributed to the data acquisition and the data interpretation. K.T. performed the statistical analysis. G.H., S.N.E., and K.T. prepared the manuscript. G.H., S.N.E, V.H., and K.T. provided intellectual content of critical importance to the work. All authors read and approved the final manuscript.
Acknowledgements
The authors thank Professor Hasan Yazıcı for critical reading of the manuscript and the Turkish Society for Rheumatology members for their contributions to the study
Collaboration Group Information: Turkish Society for Rheumatology COVID-19 Registry Investigators: Ayse Cefle, MD, Kocaeli University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Kocaeli, Turkey; Ali Karakas, MD, Dokuz Eylül University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Izmir, Turkey; Derya Kaskari, MD, Başkent University Istanbul Hospital, Department of Internal Medicine, Division of Rheumatology, Istanbul, Turkey; Samet Karahan, MD, Kayseri City Training and Research Hospital, Department of Rheumatology, Kayseri, Turkey; Dilek Tezcan, MD, Selçuk University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology Konya, Turkey; Abdurrahman Tufan, MD, Gazi University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Ankara, Turkey; Ayse Ayan, Antalya Training and Research Hospital, Department of Rheumatology, Antalya, Turkey; Levent Kılıc, MD, Hacettepe University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Ankara, Turkey; Salim Donmez, MD, Private Practice, Yalova, Turkey; Mustafa Erdogan, MD, Başakşehir Çam and Sakura City Hospital, Department of Rheumatology, Istanbul, Turkey; Veli Yazisiz, MD, Akdeniz University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Antalya, Turkey; Edip Gokalp Gok, MD, Health Sciences University, Mehmet Akif Inan Training and Research Hospital, Department of Rheumatology, Şanlıurfa, Turkey; Ahmet Eftal Yucel, MD, Başkent University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Ankara, Turkey; Elif Dincses Nas, MD, Istanbul Medeniyet University, Göztepe Training and Research Hospital, Department of Rheumatology, Istanbul, Turkey; Gezmiş Kimyon, MD, Hatay Mustafa Kemal University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Hatay, Turkey; Gunay Sahin Dalgic, MD, Başkent University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Ankara, Turkey; Hakan Erdem, MD, Medicana International Ankara Hospital, Department of Rheumatology, Ankara, Turkey; Kerem Yigit Abacar, Marmara University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Istanbul, Turkey; MD, Ridvan Mercan, MD, Namık Kemal University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Tekirdağ, Turkey; Omer Karadag, MD, Hacettepe University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Ankara, Turkey; Onay Gercik, MD, Health Sciences University, Izmir Tepecik Training and Research Hospital, Department of Rheumatology, Izmir, Turkey; Suleyman Ozbek, MD, Çukurova University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Adana, Turkey; Sebnem Gider, MD, Medicine Hospital, Istanbul, Turkey; Semih Gulle, MD, Dokuz Eylül University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Izmir, Turkey; Sibel Osken, MD, Health Sciences University, Fatih Sultan Mehmet Training and Research Hospital, Department of Rheumatology, Istanbul, Turkey; Sedat Kiraz, MD, Hacettepe University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Ankara, Turkey; Timucin Kasifoglu, MD, Eskişehir Osmangazi University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Eskişehir, Turkey; Fatma Alibaz-Oner, MD, Marmara University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Istanbul, Turkey; Izzet Fresko, MD, Istanbul University−Cerrahpaşa, Cerrahpaşa Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Istanbul, Turkey; Ali Akdogan, MD, Hacettepe University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Ankara, Turkey; Neslihan Yilmaz, MD, Demiroğlu Bilim University, Faculty of Medicine, Department of Internal Medicine, Division of Rheumatology, Istanbul, Turkey