The impact of COVID-19 infection before the vaccination era on the hospitalized patients requiring hemodialysis: a single-center retrospective cohort

Due to effective vaccinations, the COVID-19 (coronavirus disease 2019) infection that caused the pandemic has a milder clinical course. We aimed to assess the mortality of hospitalized COVID-19 patients before the vaccination era. We investigated the mortality in those patients between 1 October 2020 and 31 May 2021 who received hemodialysis treatment [patients with previously normal renal function (nCKD), patients with chronic kidney disease previously not requiring hemodialysis (CKDnonHD), chronic kidney disease (CKD), and patients on regular hemodialysis (pHD)]. In addition, participants were followed up for all-cause mortality in the National Health Service database until 1 December 2021. In our center, 83 of 108 (76.9%) were included in the analysis due to missing covariates. Over a median of 26 (interquartile range 11-266) days of follow-up, 20 of 22 (90.9%) of nCKD, 23 of 24 (95.8%) of CKDnonHD, and 17 of 37 (45.9%) pHD patients died (p < 0.001). In general, patients with nCKD had fewer comorbidities but more severe presentations. In contrast, the patients with pHD had the least severe symptoms (p < 0.001). In a model adjusted for independent predictors of all-cause mortality (C-reactive protein and serum albumin), CKDnonHD patients had increased mortality [hazard ratio (HR) 1.91, 95% confidence interval (CI), 1.02-3.60], while pHD patients had decreased mortality (HR 0.41, 95% CI 0.20-0.81) compared to nCKD patients. After further adjustment for the need for intensive care, the difference in mortality between the nCKD and pHD groups became non-significant. Despite the limitations of our study, it seems that the survival of previously hemodialysis patients was significantly better.

Automated summary

This study assessed the mortality of hospitalized COVID-19 patients before the vaccination era and found that previously hemodialysis patients had significantly better survival. In contrast, patients with chronic kidney disease who did not receive hemodialysis treatment had increased mortality.