Extremely high mortality rates among hemodialysis patients with COVID-19 before the era of SARS -CoV-2 vaccination: results from a large database from the North of Poland

INTRODuCTION Preliminary reports suggested high incidence and mortality rates of SARS-CoV-2 infec-tion in patients receiving kidney replacement therapy. OBjECTIvES We aimed to describe the incidence and outcomes of COVID-19 in hemodialysis patients. PATIENTS AND METNODS We conducted a retrospective multi center cohort study on the incidence and mortality of COVID-19 in hemodialysis patients as compared with the general adult population in the period from the beginning of the pandemic until the commencement of the SARS-CoV-2 vaccination program. The study population included all patients who were receiving hemodialysis in any of the 14 dialysis units of Pomerania Province, Poland on December 31, 2019 and all individuals who were starting long-term hemodialysis between January 1, 2020 and January 31, 2021, amounting to a total of 1567 patients. Data on the general population were obtained from reports of the health authorities. RESuLTS The absolute cumulative incidence of SARS-CoV-2 infection in hemodialysis patients was 22.4%, and after standardization for age it was 3.98-fold higher compared with the general population (P <0.001). The epidemic trajectory of both groups ran in parallel, but the increase and decline in the number of new cases occurred earlier in hemodialysis patients. The fatality rate of COVID-19 among hemodialysis patients was 30.4%. It was the highest among the oldest patients, reaching 43.81% in individuals aged 75 years or older (P = 0.003). Age -standardized fatality and mortality rates in hemodialysis patients were 5.5-and 10.9-fold higher than in controls, respectively (both P <0.001). CONCLuSIONS The results of this study show the extremely high mortality rate of COVID-19 in he-modialysis patients during the first and second waves of the epidemic in Pomerania Province, before the vaccination era.