Mortality analysis of COVID-19 infection in chronic kidney disease, haemodialysis and renal transplant patients compared with patients without kidney disease: a nationwide analysis from Turkey
Authors: Ozturk Savas , Turgutalp Kenan , Arici Mustafa , Odabas Ali Riza , Altiparmak Mehmet Riza , Aydin Zeki , Cebeci Egemen , Basturk Taner , Soypacaci Zeki , Sahin Garip , Elif Ozler Tuba , Kara Ekrem , Dheir Hamad , Eren Necmi , Suleymanlar Gultekin , Islam Mahmud , Ogutmen Melike Betul , Sengul Erkan , Ayar Yavuz , Dolarslan Murside Esra , Bakirdogen Serkan , Safak Seda , Gungor Ozkan , Sahin Idris , Mentese Ilay Berke , Merhametsiz Ozgur , Oguz Ebru Gok , Genek Dilek Gibyeli , Alpay Nadir , Aktas Nimet , Duranay Murat , Alagoz Selma , Colak Hulya , Adibelli Zelal , Pembegul Irem , Hur Ender , Azak Alper , Taymez Dilek Guven , Tatar Erhan , Kazancioglu Rumeyza , Oruc Aysegul , Yuksel Enver , Onan Engin , Turkmen Kultigin , Hasbal Nuri Baris , Gurel Ali , Yelken Berna , Sahutoglu Tuncay , Gok Mahmut , Seyahi Nurhan , Sevinc Mustafa , Ozkurt Sultan , Sipahi Savas , Bek Sibel Gokcay , Bora Feyza , Demirelli Bulent , Oto Ozgur Akin , Altunoren Orcun , Tuglular Serhan Zubeyde , Demir Mehmet Emin , Ayli Mehmet Deniz , Huddam Bulent , Tanrisev Mehmet , Bozaci Ilter , Gursu Meltem , Bakar Betul , Tokgoz Bulent , Tonbul Halil Zeki , Yildiz Alaattin , Sezer Siren , Ates Kenan 
Published: October 2020

Abstract

Background
Chronic kidney disease (CKD) and immunosuppression, such as in renal transplantation (RT), stand as one of the established potential risk factors for severe coronavirus disease 2019 (COVID-19). Case morbidity and mortality rates for any type of infection have always been much higher in CKD, haemodialysis (HD) and RT patients than in the general population. A large study comparing COVID-19 outcome in moderate to advanced CKD (Stages 3–5), HD and RT patients with a control group of patients is still lacking.

Methods
We conducted a multicentre, retrospective, observational study, involving hospitalized adult patients with COVID-19 from 47 centres in Turkey. Patients with CKD Stages 3–5, chronic HD and RT were compared with patients who had COVID-19 but no kidney disease. Demographics, comorbidities, medications, laboratory tests, COVID-19 treatments and outcome [in-hospital mortality and combined in-hospital outcome mortality or admission to the intensive care unit (ICU)] were compared.

Results
A total of 1210 patients were included [median age, 61 (quartile 1–quartile 3 48–71) years, female 551 (45.5%)] composed of four groups: control (n = 450), HD (n = 390), RT (n = 81) and CKD (n = 289). The ICU admission rate was 266/1210 (22.0%). A total of 172/1210 (14.2%) patients died. The ICU admission and in-hospital mortality rates in the CKD group [114/289 (39.4%); 95% confidence interval (CI) 33.9–45.2; and 82/289 (28.4%); 95% CI 23.9–34.5)] were significantly higher than the other groups: HD = 99/390 (25.4%; 95% CI 21.3–29.9; P &lt; 0.001) and 63/390 (16.2%; 95% CI 13.0–20.4; P &lt; 0.001); RT = 17/81 (21.0%; 95% CI 13.2–30.8; P = 0.002) and 9/81 (11.1%; 95% CI 5.7–19.5; P = 0.001); and control = 36/450 (8.0%; 95% CI 5.8–10.8; P &lt; 0.001) and 18/450 (4%; 95% CI 2.5–6.2; P &lt; 0.001). Adjusted mortality and adjusted combined outcomes in CKD group and HD groups were significantly higher than the control group [hazard ratio (HR) (95% CI) CKD: 2.88 (1.52–5.44); P = 0.001; 2.44 (1.35–4.40); P = 0.003; HD: 2.32 (1.21–4.46); P = 0.011; 2.25 (1.23–4.12); P = 0.008), respectively], but these were not significantly different in the RT from in the control group [HR (95% CI) 1.89 (0.76–4.72); P = 0.169; 1.87 (0.81–4.28); P = 0.138, respectively].

Conclusions
Hospitalized COVID-19 patients with CKDs, including Stages 3–5 CKD, HD and RT, have significantly higher mortality than patients without kidney disease. Stages 3–5 CKD patients have an in-hospital mortality rate as much as HD patients, which may be in part because of similar age and comorbidity burden. We were unable to assess if RT patients were or were not at increased risk for in-hospital mortality because of the relatively small sample size of the RT patients in this study.